PROCEEDINGS - NNSymposium · ORGANIZING COMMITTEE Ernesto Cota Araiza Chairman • Andrés Zarate Romero • Carolina Bohórquez Martínez • Francisco Mireles Higuera • Javier

April 1 – 5, 2019.

Ensenada, B.C., México

PROCEEDINGS

SPONSORS

WELCOME TO SNN 2019

Since 1995 the Center of Nanoscience and Nanotechnology (CNyN) has been organizing this event. It was designed originally with the purpose of providing a forum to researchers and graduate students of our institution for the presentation and discussion of their latest scientific results among the different areas of research in materials science carried out in CNyN. It also gave the opportunity to stimulate interactions, to exchange experiences and to strengthen or initiate new collaborations. Since then, the event has increased in attendance and naturally evolved in scope.

For the 2019 edition, the Symposium of Nanomaterials and Nanotechnology (SNN 2019) was organized jointly by CNyN and CICESE, and took place at the Riviera Convention Center in Ensenada, from April 1-5, 2019. The SNN 2019 covered topics in physical and chemical properties of nanomaterials, nanocatalysis, bionanotechnolgy, nanophotonics and technological innovations in nanoscience. There were 10 plenary speakers and 10 workshops on topics related to nanosciences.

ORGANIZING COMMITTEE

Ernesto Cota Araiza Chairman

• Andrés Zarate Romero

• Carolina Bohórquez Martínez

• Francisco Mireles Higuera

• Javier Alonso López Medina

• Julio Cesar Cruz Cárdenas

• Leonardo Morales de la Garza

• Patricia Juárez Camacho

• Raúl Rangel Rojo

• Subhash Sharma

• Trino Zepeda Partida

Book of Abstracts:

• Noemí Abundiz.

• David Domínguez.

ABSTRACT INDEX

Synthesis and Characterization of Magnetite-Zirconia Core-Shell

Nanoparticles for recoverable catalyst support .............................. 19

A comparative study based on Impedance Spectroscopy

measurements of the KNNLiLaTa compound obtained by Sol-Gel

and by RTGG ................................................................................... 20

ALD APPLICATIONS: CAPACITORS BASED ON ZrO2-AL2O3

NANOLAMINATES ........................................................................... 21

Investigation on Structural, Electrical and Multiferrioc properties of

Mn doped (0.70) BiiFeO3 - (0.30) PbTiO3 ceramics in the range 0.0 ≤

x ≤ 0.12 ........................................................................................... 22

Oxygen vacancies in ZnO and ZnO:Mn films ................................... 23

Resonantly hybridized moiré excitons in transition-metal

dichalcogenide heterostructures .................................................... 24

Valley engineering by strain in Kekulé-distorted graphene ............ 25

Driving the anisotropic energy band structure transport in semi-

Dirac materials ................................................................................ 26

Defect-related luminescence in hydroxyapatite nanobelts ............ 27

Impedance spectroscopy characterization of MOR zeolite ............. 28

Multinuclear NMR study of organic-inorganic layered hybrid

nanomaterials ................................................................................. 29

Nitrogen-induced reconstructions on the Cr(001) surface ............. 30

Non-quarter-wave dielectric mirror prepared by thermal atomic

layer deposition .............................................................................. 31

Sensitivity to index profile on rugate notch filter performance ...... 32

Stabilization of compounds that inhibit hyperglycemic effects from

Bromelia Plumieri extract supported on zeolites (FAU, MFI, HEU,

BETA and MCM-41)......................................................................... 33

Surface modification of polyethersulfone membranes by deposition

of TiO2 to achieve the photocatalytic removal of the organic

compounds comprising the cake in a filtration process .................. 34

femtosecond laser-induced periodic surface structure formation on

thin metal films upon atmospheric irradiation ............................... 35

Carbon Nanotubes and Graphene Promote Pyrolysis of Free-Base

Phthalocyanine ............................................................................... 36

Fabrication and characterization of optomagnetics nanoparticles

for the treatment of melanoma ...................................................... 37

GROWTH OF ULTRA-THIN FILMS OF ZNO ON MAGNETO-

CONTROLLABLE CORE-SHELL NANOPARTICLES ............................... 38

Hybrid diamagnetic-ferromagnetic response of SiO_2 opals with Ni

nanoparticles .................................................................................. 39

Magnetron sputtering of titanium and graphite, with and without

magnets, using DC, P-DC and RF ..................................................... 40

Understanding Bi3Ge4O12 electrochemical behavior as Li-ion

anode .............................................................................................. 41

Ag nanoparticles embedded in a magnetic composite for magnetic

separation applications ................................................................... 42

Berry phase and spin Hall current response of spin-orbit coupled

systems ........................................................................................... 43

Biopolymer-zinc oxide dressings for wound healing applications ... 44

CHARACTERIZATION OF MoS2-CNx MULTILAYER COATINGS BY

NANOINDENTATION ....................................................................... 45

Cathodoluminescence and electrical conduction mechanism on

single ZnO nanobelts ...................................................................... 46

CdS films as transport layer deposited by a novel PCD technique for

perovskite hybrid solar cells ........................................................... 47

Design and synthesis of anti-reflective filters ................................. 48

Development of aluminum-based Low-Emissivity optical filters

using double cannon sputtering technique .................................... 49

Development of field effect transistors with pseudo-MOS structure

based on GaN synthesized by CVD ................................................. 50

Effect of La3+/Sr2+ ordering on the magnetic properties of

La2/3Sr1/3MnO3 by first principles calculations ............................ 51

Effect of the Hydrogen flow: Electrical and optical properties of SRO

films with Si-ncs deposited by HFCVD ............................................. 52

Efficiency of a multilevel quantum heat engine with toroidal

geometry in a modified Carnot cycle. ............................................. 53

Electroluminescence in MOS devices with SRO films deposited by

the HFCVD technique ...................................................................... 54

Electronic transport through deformed benzene nanowires .......... 55

Evaluation of magnetite nanoparticles for the degradation of

recalcitrant reclaimed water........................................................... 56

Fabrication of a photodiode based on ZnO nanowires ................... 57

First-Principles Study of Spontaneous Polarization in BiFeO3 doped

with Lanthanum .............................................................................. 58

Gelatin-based bioactive dressings for wound healing applications 59

Low emissivity optical filters based on copper............................... 60

Magnetic Nanoparticles Based on Fe3C@ZnO for Photocatalytic

Degradation of Amaranth Dye Used in Textile and Food Industry .. 61

Measurement of the thicknesses using Raman spectroscopy of

silicon oxides grown on silicon wafers ............................................ 62

Metal nanoparticles incorporation into low density materials ....... 63

Modeling of silicon oxide formation in the hysteresis cycle in

reactive sputtering by the Co-Sputtering Simulation software and

Optical Emission Spectrometry ....................................................... 64

Morphological and structural effects on Carbon Nanotubes

subjected to oxidizing media of ozone and plasma. ....................... 65

Nanoporosity in Analcime natural Zeolites from Chiriqui, Panama:

Pristine zeolite and after Acid Treatment ....................................... 66

OXYGEN INFLUENCE ON THE CATODOLUMINESCENCE PROPERTIES

OF GAN NANORODS ....................................................................... 67

Optimizing the nitrogen content in doped carbon nanotubes inks. 68

Packing gas particles as hard spheres in a Mordenite nanopore

using Monte Carlo Simulation......................................................... 69

Bi4Ge3O12:Eu and LiGa5O8:Cr self-assembled with gold nanorods

and their potential use as a theranostic agents .............................. 70

Laser Induced Periodic Surface Structures over extended areas

using ultra-short pulsed lasers ........................................................ 71

Super-resolution imaging on metal thin films ................................. 72

Raman Spectroscopy analysis and electrical properties of

Molybdenum (Sulfur,Selenium) Transition Metal Dichalcogenide

multilayer crystals. .......................................................................... 73

Response of Au concave nanocubes LSPR to different refractive

index by modifying the medium ..................................................... 74

Second Harmonic Generation in Nanostructured Metamaterials. .. 75

Silicon quantum dots embedded on ZnO applied in silicon solar cells

........................................................................................................ 76

Spectroscopic analysis of TiN thin films deposited by DC and pulsed

reactive magnetron sputtering ....................................................... 77

Structural Characterization of Multiferroic

Pb(Fe0.5Nb0.5)O3/BiFeO3/SrRuO3 Heterostructure ..................... 78

Synthesis and characterization of multiferroic BiFeO3 thin films by

pulsed laser deposition ................................................................... 79

Thin films of CH3NH3PbI3 grown by spin-coating: optimization of

deposit conditions and study of degradation ................................. 80

TiO2 porous pellets synthesize by sol-gel and rapid liquid phase

sintering for bone cell implantation ................................................ 81

Wave packet dynamics of Kekulé-Y textured graphene .................. 82

Bi@C and vanadium oxide nanoparticle synthesis by laser ablation

of solids in liquids for biological applications and technological

applications. ................................................................................... 83

CALIBRATION CURVES FOR ATOMIC LAYER DEPOSITION ................ 84

FABRICATION OF ALD SYSTEM FOR SYNTHESIS OF TiO2 THIN FILMS

........................................................................................................ 85

Functionalization of erionite and chabazite zeolites surfaces to CO2

and CH4 capture ............................................................................. 86

Luminescent properties of Ga2O3:RE3+ nanomaterial ................... 87

MANUFACTURING OF ALD SYSTEM FOR THE SYNTHESIS OF ZnO

THIN FILMS ..................................................................................... 88

Effect of La3+/Sr2+ ordering on the magnetic properties of

La2/3Sr1/3MnO3 by first principles calculations ............................ 89

On the Structure and Electronic Properties of LTA-Zeolite ............. 90

STUDYING THE PROPERTIES OF POROUS MATERIALS BY HARD

SPHERES AND MOLECULAR DYNAMICS APPROACH: PARTICLE

COLLISIONS IN IRREGULAR CHANNELS ........................................... 91

Nanometric analysis of an axon including a carbon nanotube ....... 92

Structure and dynamics of organic molecules intercalated in

H2La3Ti3O10 layered perovskite photocatalyst ............................. 93

Study of UNCD thin films for cover ion-litium batteries .................. 94

Effect of antimicrobial nanocomposites on Vibrio cholerae biofilm

formation ........................................................................................ 95

Silver nanoparticles for the cytotoxic and modulatory activity effect

of the multidrug-resistant associated P-glycoprotein in breast

cancer cell lines. .............................................................................. 96

Characterization of bifenthrin nanoparticles synthesized by laser

ablation of solids in liquids. ............................................................ 97

Inhalable rutile nanoparticulate in atmospheric dust ..................... 98

NEW APPROACHES FOR NANOTOXICOLOGY EVALUATIONS: A

THREE-DIMENSIONAL CELL CULTURE SYSTEM ................................ 99

Pegylated cyclodextrins: uncovering their nanoassemblies .......... 100

A platform for the incorporation of proteins and peptides into

genetically-encoded crystals ......................................................... 101

Effect of an extra carbon source and inoculum in a biofuel cell with

living hydrophytes ........................................................................ 102

Enzymatic synthesis of indigo-derivative industrial dyes .............. 103

In vitro biocompatibility evaluation of europium-doped

hydroxyapatite nanoparticles ....................................................... 104

Physicochemical Characterization of Palladium nanoparticles using

Polydatin ....................................................................................... 105

BMV VLPs-Insulin .......................................................................... 106

Characterization of polyethylene terephthalate (PET) nanoparticles

and their toxicity evaluation in two cell lines in vitro. .................. 107

Citotoxicity effect of Co0.25Zn0.75Fe2O4 magnetic nanofluid on

different tissues of Balb/c mice primary cultures ......................... 108

Design micro-electro-mechanical systems (MEMS) variables of an

air-microfluidic sensor for the study of particulate matter ........... 109

Enzymatic detoxification of endocrine disruptors ........................ 110

Green synthesis of silver nanoparticles by using strawberry

(Fragaria ananassa) extract: Characterization and antibacterial

activity .......................................................................................... 111

Machine Learning to Identify Luminescent Nanoparticles in Cancer

Cells .............................................................................................. 112

Molecular modeling simulation studies reveal new potential

inhibitors against HPV E6 protein ................................................. 113

Nanotechnology to the Rescue of a Proudly Mexican Plant: Vanilla

...................................................................................................... 114

Interaction of silver nanoparticles with boilogical systems in vitro

(Entamoeba histolytica) ................................................................ 115

Antimicrobial properties of ZSM-40 type zeolite functionalized with

silver ions and silver nanoparticles ............................................... 116

In vitro cytotoxicity of Protein-Coated Silver Nanoparticles on Mice

Primary Cultures ........................................................................... 117

CYTOTOXIC EFFECT OF 5 DIFFERENT SILVER NANOPARTICLES IN

VITRO ON MICE LIVER, SPLEEN, BONE MARROW, AORTA, KIDNEY

AND HEART PRIMARY CULTURES .................................................. 118

Proposal of a new Antipsychotic derivative of clozapine absent of

cardiometabolic side-effects by means of in silico methods ....... 119

Silver Nanoparticles Efficiency in Diabetes Foot Ulcers Treatment in

Private Health Services at Ensenada, Baja California, in the Period

August-December 2018 ................................................................ 120

Design and fabrication of Al2O3 slab optical waveguides by Atomic

Layer Deposition using H2O and O3 as reactants. ........................ 121

Geometric phases in photon shuttle optomechanical system ...... 122

TDDFT study of excited states of Br2 in clathrates cages .............. 123

Characterization of nanolaminated slab optical waveguides ........ 124

Chitosan modifications to get an electroluminescent material .... 125

Design of integrated optical components for quantum devices on a

silicon nitride platform ................................................................. 126

Light Emission Properties Characterization of 2D Heterostructure

Layered Materials (WS2 and MoS2) by Confocal and Scanning Near

Field Optical Microscopy ............................................................... 127

Light driven nanoparticles as photonic motors ............................. 128

Second harmonic generation response from gold metallic

nanoprism arrays under focused illumination .............................. 129

Silicon nitride optical waveguides for quantum optics applications

...................................................................................................... 130

Two-photon absorption of ZnO nanoparticles synthesized by laser

ablation of solids in liquids ........................................................... 131

Nanopartículas y medio quirales orgánicos con poder óptico

rotatorio para la modificación de la birrefringencia de fibras de

cristal fotónico de núcleo hueco ................................................... 132

Improved colloidal synthesis of Ni and Co metal nanoparticles to

catalyze selectively hydrodeoxygenation of C4-C5 oxygenates .... 133

Rational design of highly active layered double hydroxides for

electrocatalytic water oxidation ................................................... 134

OBTENCIÓN Y CARACTERIZACIÓN DE COMPOSITOS DE TiO2-

ZEOLITAS ....................................................................................... 135

Synthesis, Characterization and Catalytic Properties of Dandelion

Flower like NiYMo Catalysts .......................................................... 136

The inclusion of iron into zeolite framework instead of aluminum:

the influence of synthesis conditions............................................ 137

THE EFFECT OF IRON VALENCE ON THE PROPERTIES OF A COPPER-

IRON BIMETALLIC SYSTEM SUPPORTED ON MORDENITE ............. 138

Synthesis of G-ZnO composite thin films for improved photovoltaic

performance in solar cells. ............................................................ 139

Synthesis and characterization of MFI type zeolite doped with TiO2,

and its subsequent evaluation in the photocatalytic degradation of

dyes. ............................................................................................. 140

SnOx thin films by magnetron sputtering dc varying the partial

pressure of oxygen for their use in p-n junctions ......................... 141

SYNTHESIS OF C-DOTS FROM GRAPE FRUIT, USING GREEN

NANOTECHNOLOGY BY ASSISTED MICROWAVE TECHNIQUE. ...... 142

Promoting the catalytic activity from pure Pd nanoclusters to

M@PdPt (M=Co, Ni Cu) core-shell nanoclusters for the oxygen

reduction reaction ........................................................................ 143

Platinum sulfides: Synthesis, characterization and performance

towards ORR ................................................................................. 144

Order determination of the ionic exchange equation in the zeolite

(ZSM-5 Si/Al = 40) system and AgNO3 solution, varying temperature

...................................................................................................... 145

NANOESTRUCTURED NiW CATALYSTS FOR 3-METHYL THIOPHENE

HYDRODESULFURIZATION ............................................................ 146

Low temperature Atomic Layer Deposition of Ruthenium thin films

using Ozone as a reactant ............................................................. 147

Ion exchange equilibrium curve between Mg(NO3)2 in solution and

Zeolite type "Y" with ratio Si / Al = 15 ........................................... 148

Interaction of CO and NO with mono- and bimetallic Ag, Fe systems

on mordenite: A FTIR study at room temperature ....................... 149

Hydrogen bond interactions induce of the formation 1-(2-Furoyl)-3-

phenylthiourea multilayers on Au(111) ........................................ 150

Hydrogen bond interactions induce formation 1-(aroyl)-3-

(substituted) thiourea multilayers on Au(111).............................. 151

GREEN NANOTECHNOLOGY: C-DOTS SYNTHETIZED FROM CITRUS

FRUITS........................................................................................... 152

Fabrication of a TiO2/ZnO photocatalyst anchored on vertically

aligned carbon nanotubes ............................................................ 153

Electrospun membranes of PMMA-ZnO for the dye degradation

under exposure natural ................................................................ 154

Effect of the reduction temperature on the final size of the nickel

clusters synthesized in the "Y" type zeolite, with Si / Al = 15, ratio.

...................................................................................................... 155

Effect of the ion exchange cycles on the final size of the Mg

nanoparticles obtained in "Y" Zeolite with Si / Al ratio = 15 ......... 156

Effect of metal oxide and carbon supports on catalytic performance

of bimetallic nanoparticles in lignocellulose-derived levulinic acid

hydrogenation .............................................................................. 157

Effect of iron ions on formation of silver species in mordenite .... 158

Defective graphene nanosheets for nucleobases adsorption and

detection: A theoretical description. ............................................ 159

Cu-Ag bimetallic systems supported on clinoptilolite and

mordenite: a study of NO adsorption by Temperature Programmed

Desorption, and NO selective catalytic reduction ......................... 160

Cooperative effect of IrRe for selective hydrodeoxygenation of

lignocellulose derived oxygenates: levulinic acid and crotone

aldehyde ....................................................................................... 161

Characterization of Copper Sites in Mordenites by Low-

Temperature FTIR Spectra of Adsorbed CO .................................. 162

Al2O3-TiO2-W Catalysts; Effect of Acid-Basic Sites Ratio on the

Catalytic Activity for 5-HMF .......................................................... 163

Physicochemical properties of Cu- and Pd- oxides over mixed γ–χ–

Al2O3 for methanol dehydration .................................................. 164

FTIR spectroscopy for the studies of catalysts and catalytic reaction

mechanisms .................................................................................. 165

Activation of MoS2 Monolayers by Substitutional Copper and Silver

Atoms Embedded in Sulfur Vacancies: A Theoretical Study. ......... 166

Ab initio study and growth of superconducting tantalum nitride thin

films by pulsed laser deposition.................................................... 167

Colloidal Ru nanoparticles: preparation, structural and catalytic

properties in synthesis of biofuel components from lignocellulose-

derived oxygenates ....................................................................... 168

Synthesis of g-C3N4/metal oxide composites and their

photocatalytic Applications .......................................................... 169

Physicochemical properties of the luminescent material

Li3Ba2La3(MoO4)8:(Eu3+,Tb3+) fabricated by combustion synthesis

...................................................................................................... 170

CARBON-DOPED NANOSTRUCTURES IN FUEL CELLS ..................... 171

Electrical characterization in an Au-YSZ-Ru structure ................... 172

Confinement of supported Au nanoparticles with alumina by atomic

layer deposition: their catalytic performance as nanoreactors in the

4-nitrophenol reduction ............................................................... 173

Nanostructured TiO2-MWCNT Novel Materials for Eletrocatalytic

Aplications .................................................................................... 174

The first stage of ZnO nanostructures growth via controlled thermal

oxidation: a combined experimental and theoretical study ......... 175

Mesoporous silica used like a drug delivery and derivates

composites silica-carbon was proved as a a heterogenous catalyst

...................................................................................................... 176

Characterization of modified natural mordenite with distinct levels

of dealumination .......................................................................... 177

Au@CeO2 nanoreactors with different crystallinity of ceria shell

obtained by hydrothermal method .............................................. 178

One-Pot synthesis of Au@Cex-Zry-O nanoreactors: active

performance at low temperature at 4-nitrophenol reduction to 4-

aminophenol................................................................................. 179

Comparative studio of Pt/C in the preparation of cathodic

electrodes for fuel cells ................................................................. 180

GOOD PRACTICES FOR REPORTING PHOTOCATALYTIC EVALUATION

OF VISIBLE-LIGHT ACTIVE SEMICONDUCTORS: Bi2O3 CASE STUDY

...................................................................................................... 181

ORGANOMETALLIC PRECURSORS OF HYDRODESULFURATION

CATALYSTS: SYNTHESIS, CHARACTERIZATION AND EVALUATION 182

Adsorption of chlorinated compounds, alkanes and BTX in

nanoporous Cu/SiO2, Fe/SiO2 and Ag/SiO2 ................................. 183

Effect of the cycles of cationic exchange, on the last size of silver

nanoparticles in Zeolite “Y” .......................................................... 184

Effect of the reduction temperature on the final size of the silver

nanoparticles supported on Zeolite "Y" with Si / Al = 15, ratio. .... 185

Green synthesis and characterization of composites type silver

nanoparticles-bivalve mollusk shell .............................................. 186

Obtention and Surface modification of cellulose nanocrystals

extracted from agave bagasse ...................................................... 187

Application of metal oxide nanofluids in a Compact Solar Collector

...................................................................................................... 188

CdSe-based thin film transistors with SiO2/PVP hybrid gate

dielectric. ...................................................................................... 189

Composite materials of natural zeolite modified with N, P and

organic nitrogenous substances for agroecological purposes ...... 190

Design of optical ring resonator based on optical waveguides ..... 191

Low cost instrumentation system for Van der Pauw measurements

...................................................................................................... 192

Low temperature processing of HfAlOx-PVP hybrid films with

applications to electronic devices. ................................................ 193

Prototype design for energy storage nano-devices of low current

and high temperature operation .................................................. 194

Synthesis of AlN & TiN thin films: An optical emission spectroscopy

study ............................................................................................. 195

Low-temperature evaluation of state charge of the nanostructured

Au-YSZ-Ru fuel cell. ....................................................................... 196

Symposium of Nanoscience and Nanomaterials 2019, 1-5 April, 2019, Ensenada, B.C., México

AMPN - 1

e-mail: [email protected]

Synthesis and Characterization of Magnetite-Zirconia Core-Shell Nanoparticles for recoverable catalyst support

J.Alejandro M. [*,1]; Yasmin E.[2]; Sergio F. [2]; J.Noé D.[2]; Julián H. [1];Teresa H.[1]

Universidad Veracruzana-Centro de Investigación en Micro y Nanotecnología, Boca del Río, Veracruz, México; Universidad Nacional Autónoma de Mexico, Centro

de Nanociencias y Nanotecnología, Ensenada B.C., México.

Magnetic core-shell nanoparticles of magnetite- zirconia were synthesized by co precipitation and

solution methods. We obtain the magnetic core from a single inorganic Fe2+ salt precursor and

ammonia hydroxide as a precipitating agent. This reaction occurred only assisted by ultrasonically

agitation without any other energy source nor N2 atmosphere. A functionalized process with citric

acid was first applied in order to cover the magnetite surface core with zirconia, from an aqueous

inorganic Zr4+ salt solution and calcined process at 450°C. With this core-shell structure we bring

the protection of zirconia against magnetite oxidation and a recoverable characteristic to the entire

catalyst support. Material characterization was performed in Transmission Electron Microscopy

(TEM), X-Ray Diffraction (XRD) and Raman Spectroscopy to confirm the core-shell nanoparticles

morphology.

Acknowledgments

To project SNER-CONACyT 117373. We thank to G. Torres, F. Ruiz, Y. Kotolevich, J.M. Romo and

Nanomaterials Synthesis Lab CNyN-UNAM


AMPN - 2


A comparative study based on Impedance Spectroscopy measurements of the KNNLiLaTa compound obtained by Sol-Gel and by RTGG

J. Portelles [1, 2, 3]; R. López [2]; G. Rojas George [4]; J. Fuentes [1, 2]; E. Carrillo [2]; O. Raymond [3]; J. M. Siqueiros [3]

Facultad de Física, Universidad de La Habana, San Lázaro y L, 10400, Cuba; Instituto de Cibernética, Matemática y Física, ICIMAF,10400, CITMA, Cuba; Centro de

Nanociencias y Nanotecnologia, UNAM, Ensenada, B.C, México; Centro de Investigación en Materiales Avanzados, CIMAV, Chihuahua, Chihuahua, México

This work presents a discussion of the results of the characterization of the ac conductivity of

KNNLiLaTa polycristalline piezoelectric ceramics obtained by the Sol-Gel technique. The effect of La

doping on the KNNLiTa compound, taken as the basic material, is to shift its phase transition

temperatures (orthorhombic-to-tetragonal and tetragonal-to-cubic) toward lower values.

Impedance Spectroscopy was used to measure the ac conductivity in the 100 Hz to 1 MHz frequency

range at temperatures between 75 and 500 C. It is found that the conductivity follows Jonscher´s

universal law. The experimental values of the activation energy of the different conduction

mechanisms and hoping frequency are determined and discussed. Finally, these results are

compared with those from samples of the same compound obtained by the reactive templated grain

growth (RTGG) method.

We acknowledge DGAPA-UNAM financial support through Grants IN107918 and IN105317.

Key words: Conductivity, Impedance Spectroscopy, KNN.


AMPN - 3


ALD APPLICATIONS: CAPACITORS BASED ON ZrO2-AL2O3 NANOLAMINATES

J. Jurado[1*]; M. Franco[2]; B. Sanchez[2]; N. Radnev[3]; E. Murillo[4]; D. Dominguez[4]; J. Lopez[4]; H. Tiznado[4]

Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California,

México; Universidad Autónoma de Baja California, Campus Ensenada, Km. 106 Carretera Tijuana-Ensenada, 22800, Ensenada, Baja California, México; Instituto de

Ingeniería, Universidad Autónoma de baja California, Blvd. Benito Juárez y calle de la Normal s/n Col. Insurgentes Este, C.P. 21280 Mexicali, Baja California, México;

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14 C.P. 22800, Ensenada, Baja California, México ;

MOS (Metal - Oxide – Semiconductor) capacitors have used Silicon Oxide (SiO2) for many years as

dielectric material, but the need for miniaturization and development of these has taken this

material to its limits. One of the promising materials to replace SiO2 is Zirconium Oxide (ZrO2), one

of the problems of using ZrO2 as a dielectric material is that it allows high leakage currents

attributed to crystallization of material. One way to solve this problem is by adding a laminate of

Aluminum Oxide (Al2O3, amorphous material) between the film to prevent crystallization. In this

project, MOS capacitors were fabricated using nanolaminates of Al2O3 and ZrO2 (AZrA) as dielectric

material, synthesized by the plasma enhanced atomic layer deposition technique (PEALD). The gold

electrodes were deposited by thermal evaporation. The thickness and bandgap of the

nanolaminates were measured by ellipsometry and UV-Vis spectroscopy, obtaining a control of

thickness and modulation of the bandgap. The X-ray photoelectron (XPS) spectrum shows the

characteristic peaks of Al2O3 and ZrO2, after the erosion of Argon (Ar) decreases the concentration

of impurities of carbon (C) attributed to the synthesis technique (PEALD). The thin film of ZrO2 shows

a roughness of root mean square (RMS) 1.686 and 0.625 nm for Al2O3 measured by Atomico Force

Microscopy (AFM). The X-Ray Diffraction (XRD) spectrum shows cubic crystalline phase for the ZrO2

film and amorphous for the Al2O3 film. For the electrical characterization curves capacitance -

voltage (C-V) and current - voltage (I-V) were acquired, obtaining a control of the capacitance,

dielectric constant, Equivalent Oxide Thickness (EOT), leakage current and breakdown voltage.

We acknowledge to DGAPA-UNAM, PAPIIT (Grants No. IN-110018, IN-112117 and IA-101018),

PAPIME (Grants No. PE-100318 and PE101317), FORDECyT (Grant No. 272894). The authors would

like to thank Marcelo Martinez, Alejandro Tiznado and Enrique Medina for technical assistance.


AMPN - 4


Investigation on Structural, Electrical and Multiferrioc properties of Mn doped (0.70) BiiFeO3 - (0.30) PbTiO3 ceramics in the range 0.0 ≤ x ≤ 0.12

Subhash Sharma [1,2]; Diana E. Vazquez Valerdi [1]; J. M. Siqueiros [1]; and O. Raymond-Herrera [1]

Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 Carretera Tijuana-Ensenada. Apartado Postal 14, C. P. 22800,

Ensenada, B. C. México.; Investigador de Cátedras CONACYT en Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México

Abstract: This report describes our studies on solid solution composition of (0.70)BiFeO3 –

(0.30)PbTiO3 with doping of Mn with x ≤ 0.12. The substitution of Mn in BFO –PT can cause a

structural distortion due to the ionic radii mismatch between Mn and Fe ions. Rietveld refinement

of XRD data demonstrated the co-existence of tetragonal (P4mm) and rhombohedral (R3c)

symmetry phases for pure and Mn doped samples up to x = 0.06. Thereafter, structural

transformation has been observed from two phases (R+T) co-existence to tetragonal (T) phase upto

x = 0.12. These structural transitions with increasing x may be attributed to the ionic radii mismatch

between dopants Mn and host cations (Fe3+ and Ti4+). Dielectric studies have revealed that

dielectric constant (Ɛr) increases and dielectric loss (tan δ) decreases with x for all samples. This

improvement in dielectric response may arise due to the increased volume percentage of tetragonal

phases. Suppression in defect concentration is also supported by measurement of Leakage current

density which is found to decrease with increase x. M-H hysteresis data has revealed weak

ferromagnetism for BFO – PT solid solution and enhanced magnetization in Mn modified BFO – PT

ceramics. It has been observed that large value of remnant magnetization (Mr) for Mn may be

attributed to the contributions of magnetic moment due to high spin state of Mn.

Acknowledgments

We thankfully acknowledge the CONACyT for support by the program Catedras CONACyT.

*e-mail: [email protected]; [email protected]


AMPN - 5


Oxygen vacancies in ZnO and ZnO:Mn films

Carolina Bohorquez Martinez[*, 1]; Manuel Herrera Zaldivar [2]

Centro de Investigación Científica y de Educación Superior de Ensenada; Centro de Nanociencias y Nanotecnologia-Universidad Nacional Autónoma de México

Dilute magnetic semiconductors (DMS) combine the semiconductor and ferromagnetic properties.

The origin of ferromagnetic in these materials is not clear because conventional superexchange of

double-exchange interactions cannot explain the long-range magnetic order. Moreover, exchange

interactions mediated by point defects in the semiconductor host has been proposed by several

authors as a mechanism that explains the origin of ferromagnetism. In this study, we used the

cathodoluminescence (CL) and scanning tunneling spectroscopy (STS) techniques to demonstrate

that Mn doping generates oxygen vacancies in ZnO films, besides donor defect-related states with

activation energies between 1.2 and 0.4 eV. Specifically, CL spectra from undoped ZnO films show

two bands centered at 3.2 and 2.45 eV, attributed to the band edge and the oxygen vacancy-related

emissions, respectively, while CL spectra from Mn-doped ZnO films revealed a significant increase

in the intensity of the 2,45 eV emission. STS measurements revealed that ZnO:Mn films possesses

both donor states at 1.1 and 1.7 eV above the Fermi level, and acceptor states at 0.5 eV below the

Fermi level. ZnO:Mn films were also characterized by magnetic force microscopy (MFM) to

determinate the magnetic response generated by Mn doping.

Acknowledgment to PAPIIT IN101917 project.


AMPN - 6


Resonantly hybridized moiré excitons in transition-metal dichalcogenide heterostructures

David A. Ruiz-Tijerina* [1, 3 ; Evgeny M. Alexeev [2 ; Alexander I. Tartakovsky [2 ; Vladimir E. Fal'ko [3]

CNyN-UNAM; University of Sheffield; National Graphene Institute and University of Manchester

Transition-metal dichalcogenides (TMDs) are two-dimensional direct-gap semiconductors, whose

optoelectronic properties are determined by the formation of excitons (Xs): electrostatically bound

states of electrons and holes. Vertical TMD hetero-bilayers, held together by weak van der Waals

forces, can form with arbitrary interlayer orientation, exhibiting polar interlayer excitons (iXs),

formed by electrons and holes in opposite layers. We present a theoretical and experimental

analysis of the optical spectrum of MoSe2/WS2 hetero-bilayers, where X and iX states hybridize

strongly, due to an accidental resonant condition between the conduction bands of the two TMDs.

This gives rise to hybridized excitons (hXs), which inherit the strong coupling to light of MoSe2 Xs,

as well as the polar nature of iXs. In the presence of a moiré superlattice, which appears in the

heterostructure for small twist angles, our results reveal the formation of moiré exciton minibands,

and the appearance of secondary optical signatures enabled by moiré umklapp processes, giving

explicit evidence of the influence of moiré physics on the electronic, excitonic and optical properties

of TMD heterostructures.


AMPN - 7


Valley engineering by strain in Kekulé-distorted graphene

Elias Andrade[1,2]; Ramon Carrillo-Bastos*[1];Gerardo G. Naumis [2]

Facultad de Ciencias, UABC [1]; Instituto de Física, UNAM[2]

A Kekulé bond texture in graphene modifies the electronic band structure by folding the Brillouin

zone and bringing the two inequivalent Dirac points to the center. This can result in the opening of

a gap (Kek-O) or the locking of the valley degree of freedom with the direction of motion (Kek-Y).

We analyze the effects of uniaxial strain on the band structure of Kekulé-distorted graphene for

both textures. Using a tight-binding approach, we introduce strain by considering the hopping

renormalization and corresponding geometrical modifications of the Brillouin zone. We numerically

evaluate the dispersion relation and present analytical expressions for the low-energy limit. Our

results indicate the emergence of a Zeeman-like term due to the coupling of the pseudospin with

the pseudomagnetic strain potential which separates the valleys by moving them in opposite

directions away from the center of the Brillouin zone. For the Kek-O phase, this results in a

competition between the Kekulé parameter that opens a gap and the magnitude of strain which

closes it, while for the Kek-Y phase, it results in a superposition of two shifted Dirac cones. As the

Dirac cones are much closer in the superlattice reciprocal space than in pristine graphene, we

propose strain as a control parameter for intervalley scattering.

Reference: Phys. Rev. B 99, 035411: https://doi.org/10.1103/PhysRevB.99.035411


AMPN - 8


Driving the anisotropic energy band structure transport in semi-Dirac materials

Alexander Lopez

ESPOL

We present a model for a semi-Dirac material subject to ac driving. Exploring the qusi-energy

spectrum, we find that certain directions in k-space remain insensitive to the modulation effects

and use a low-energy effective Hamiltonian to show that by properly tuning the driving strength,

pseudospin polarization inversion can be enhanced on demand by properly tuning the system and

establish the most apropriate parameter regimes for an actual experimental realization.


AMPN - 9


Defect-related luminescence in hydroxyapatite nanobelts

V. Huerta [*, 1, 2]; M. Herrera [2]; V. Gómez [2]; R. Silva [3]

CICESE; UNAM; BUAP

Hydroxyapatite [Ca10(PO4)6(OH)2, HAp] is the main biomineral component found in bone tissue

like teeth and bones. For several decades, synthetic HAp with excellent biocompatibility, bioactivity,

and osteoconductivity, has been obtained and used for a great variety of biomedical applications

such as replacements for bone injuries, drug delivery agents and bioactive coating on metallic

osseous implants and dental materials; also, it has been of great interest to use HAp to acquire

contrast-enhanced images from magnetic resonance, X-ray and near-infrared reflection imaging,

when doped with rare-earth ions. In this work, HAp nanobelts were synthesized by a modified

hydrothermal method and then characterized by different techniques to determine their structural,

morphological and luminescent properties. The HAp nanostructures exhibited a hexagonal crystal

lattice, with calcium-deficient HAp as the predominant phase, showed a high crystallinity and

revealed a thin belt-type morphology with lengths from 0.5 to 1 μm and widths between 10 and 100

nm. EDS and XPS measurements demonstrated the calcium deficiency in HAp nanobelts, which

resulted to be higher on their surface. Electron paramagnetic resonance (EPR) measurements

obtained for these HAp nanostructures showed absorptions for paramagnetic defects attributed to

carbon dioxide ions (CO2-) with g-tensor values of gx=2.0033, gy= 2.0019 and gz= 1.9971, as well as

ionized oxygen vacancies (VO-) with a value of g= 1.9993. Finally, photoluminescence (PL) and

cathodoluminescence (CL) spectra for these nanobelts obtained in the visible range, revealed the

presence of several emission bands attributed to ionized calcium- and hydroxyl vacancies in the HAp

lattice, while CL emission spectra in the near-infrared (NIR) range confirmed the generation of

emissions associated with the presence of oxygen vacancies (VO-).


AMPN - 10


Impedance spectroscopy characterization of MOR zeolite

Fabian N. Murrieta-Rico[*,1]; Vitalii Petranovskii[2]; Jorge Portelles[3]; Oscar Raymond-Herrera[2]; Juan de Dios Sanchez-Lopez[1]; Juan I. Nieto-Hipolito[1]; Mabel Vazquez-Briseño[1]

Facultad de Ingeniería, Arquitectura y Diseño, UABC;Centro de Nanociencias y Nanotecnología, UNAM;Facultad de Física, Universidad de La Habana

Zeolites are materials that are of interest due their unique combination of properties, such as ionic

exchange capacity, uniform morphology of voids (channels and cavities), and selective adsorption.

Zeolites could be used as ionic conductors for applications like solid state batteries or sensors.

Because of their crystalline structure, zeolites offer good prerequisites to be fast ionic conductors

due to their one-, two- or three-dimensional channel systems and their cation exchange ability [1].

The conductivity of zeolites has an ionic nature and is a consequence of the migration of cations in

the crystalline zeolite framework [2].

Impedance spectroscopy is a technique for analyzing the electrical properties of ionic,

semiconducting or insulating materials. Using impedance spectroscopy, we can get information

about the bulk phase of materials, such as conductivity and dielectric constant. In addition, we can

obtain data from outer interfaces, like the capacitance of the interfacial region, and the derived

quantities [3]. For zeolites, ionic conductivity can be determined using impedance spectroscopy.

This work reports a preliminary analysis of mordenite using impedance spectroscopy. The result is

the dependence of the impedance, conductivity and activation energy on frequency.

[1] Kelemen, G. and Schön, G., 1992. Ionic conductivity in dehydrated zeolites. Journal of materials

science, 27(22), pp.6036-6040.

[2] Freeman Jr, D.C. and Stamires, D.N., 1961. Electrical conductivity of synthetic crystalline zeolites.

The Journal of Chemical Physics, 35(3), pp.799-806.

[3] A. Janshoff, H.-J. Galla, y C. Steinem. Chapter 36 - Biochemical Applications of Solid Supported

Membranes on Gold Surfaces: Quartz Crystal Microbalance and Impedance Analysis, in Membrane

Science and Technology, vol. 7, H. T. Tien y A. Ottova-Leitmannova, Eds. Elsevier, 2003, pp. 991-

1016.


AMPN - 11


Multinuclear NMR study of organic-inorganic layered hybrid nanomaterials

Shelyapina M.G. [*,1]; Zhelezniak Yu. [1]; Krylova E.A. [1]; Zvereva I.A. [1]; Chislov M. [1]; Petranovskii V. [2]; Yocupicio-Gaxiola R. [2]; Antunez-Garcia J. [2]; Rodriguez-Iznaga I. [3]; Fuentes S. [2]

Saint Petersburg State University, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia; Centro de Nanociencias y Nanotecnología, Universidad Nacional

Autónoma de México, Ensenada, Baja California, C.P. 22860 México; Instituto de Ciencias y Tecnología de Materiales (IMRE) – Universidad de La Habana. Zapata y

G, s/n La Habana 10400, Cuba

Organic-inorganic layered hybrid nanomaterials have drawn great attention due to their widespread

use in various areas. Layered zeolite precursor is an attractive intermediate to design hierarchical

mesoporous/nanoporous catalysts. To control the growth of 2D zeolite nanosheets in hydrothermal

synthesis, some complex surfactants are employed. For the successful development of these

composite organic-inorganic nanomaterials, knowledge on the structure and dynamics of both

structural parts is essential. Nowadays Nuclear Magnetic Resonance (NMR) spectroscopy and

relaxation have become very powerful techniques for characterizing hybrid organic/inorganic

nanomaterials since they can provide information on structural and dynamic issues associated with

both organic intercalated molecules and the inorganic part as well.

Here we report the results of our multinuclear 1H, 13C, 15N, 23Na, 27Al, 29Si NMR at 9.4 T studies

of two class of materials: mesostructured zeolite materials, with the MOR and ZSM-5 structures,

grown as lamellar phases using cetyltrimethylammonium bromide and polyethylene glycol (CTAB-

PEG) as a mesopore creating agent in a one-pot synthesis. 13C and 15N MAS spectra were obtained

in cross polarization regime. To investigate the guest–host interaction between the inorganic layers

and intercalated organic surfactant, two-dimensional 1H-29Si and 1H-13C HETCOR NMR

experiments were performed. To study the dynamics of guest molecules, spin-lattice relaxation

processes of 13C and 1H nuclei were studied.

The synthesis and structural characterization of the materials were done at the Nanoscience and

Nanotechnology Centre of UNAM. The thermal analysis and NMR studies were carried out at the

Research Park of SPSU: Centre of Thermal Analysis and Calorimetry and Centre for Magnetic

Resonance. The work was partly supported by SENER-CONACYT (project 117373), RFBR and CITMA

in accordance with research Project No. 18-53-34004.


AMPN - 12


Nitrogen-induced reconstructions on the Cr(001) surface

Emiliano Ventura-Macias [*,1,2]; J. Guerrero-Sánchez [2]; Noboru Takeuchi [2]

Posgrado en Nanociencias, Centro de Investigación Científica y Estudios Superiores de Ensenada; Centro de Nanociencias y Nanotecnología, Universidad Nacional

Autónoma de México

Chromium has generated interest as a spintronic material for its antiferromagnetic alignment at

room temperature. Nevertheless, reactive gases like nitrogen easily contaminate pristine Cr

surfaces, reconstructing the surface and modifying its properties. In a recent study of the spin

properties of Cr(001) with adsorbed N, the surface reconstruction model could not be assigned to

known models [1]. Thus, we use the spin-polarized density functional theory to describe new

reconstructions models.

Our primary goal is to clarify the atomic structure of the N induced c(2x2) Cr(001) reconstruction

and to study its properties. After analyzing the relative stability of several models with a ½

monolayer of N atoms on the surface, it was found that only two models were stable for different

growth conditions. The first stable configuration model shows two N atoms (per cell) adsorbed on

hollow sites following a diagonal pattern. In the second, N atoms replace Cr atoms of the first

monolayer, and after optimization, they end up in almost second layer positions.

To compare with Scanning Tunneling Microscopy experiments, we obtained simulated STM images

using the Tersoff-Hamann approximation. In addition to these images, we projected the local

density of the states in the first two layers and the spin density on the (001) plane. From these

projections, we determined that almost all the electron density near the Fermi energy comes from

first layer Cr and that N electron density is further away from the Fermi energy, so they not appear

in the images. Also, our two models can explain the two different c(2x2) Cr(001) reconstructions

observed experimentally. In particular, the first model, with N atoms adsorbed on the surface,

reproduce the STM images found in the recent study by J.P. Corbett and A.R. Smith [1].

[1] J.P. Corbett, A.R. Smith, Journal of Magnetism and Magnetic Materials, 465 (2018) 626-633. doi:

10.1016/j.jmmm.2018.06.037.


AMPN - 13


Non-quarter-wave dielectric mirror prepared by thermal atomic layer deposition

J. Lopez [1, *]; H. Márquez [2]; H. Borbón - Nuñez [1]; N. Abundiz [1]; R. Machorro [3]; M. H. Farías [3]; H. Tiznado [3]; G. Soto [3]

CONACYT - Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, B.C. – México; Centro de

Investigación Científica y Educación Superior de Ensenada - CICESE, Ensenada 22860, México; Centro de Nanociencias y Nanotecnología, Universidad Nacional

Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, B.C. – México.

In this work we design and fabricate from n( ) and k( ) experimental data for both Al2O3 and TiO2

single layer materials, an optical coating as “Non-quarter-wave dielectric mirror” following the stack

formula (HxLy)8Hx. Optical coating based on multilayer film on BK7 glass and Si(100) wafer

substrates, was grown by thermal atomic layer deposition at 150 °C. Optical constants and optical

properties of the Al2O3 - TiO2 multilayer stack, before and after thermal treatment at 450 °C, were

studied via spectroscopy ellipsometry and UV – Vis measurements in the spectral range from 200 to

1100 nm. Also, similar samples were studied by means of TEM, SEM and AFM at room temperature

in order to obtain information about the morphological properties. From optical studies, we found

a reject zone or “stopband region” between 381 - 451 nm, with maximum reflection around of 99.9

%, cut-off points at 371 and 455 nm after thermal treatment. This reject zone presents an acceptable

bandwidth at 0 = 420 nm reference wavelength. Results open the possibility to fabricate dielectric-

mirrors on complex substrates without the restriction of direct evaporate exposed-view, due to the

conformality advantage of ALD technology and its affinity with integrated nanotechnology

applications.

Keywords: Optical coating; multilayers stacks; dielectric mirror; atomic layer deposition.

Acknowledgments

This work was partially supported by Dirección General de Asuntos del Personal Académico DGAPA-

UNAM - by, through research projects: PAPIIT IN 112117, IA 101018, IN 110018 and IA 103117,

PAPIME PE100318, PE101317 and FORDECYT - CONACYT 272894. Authors would like to thank

valuable technical support by Eloisa Aparicio, Eduardo Murillo, David Dominguez, Israel Gradilla,

Francisco Ruíz and Jaime Mendoza.


AMPN - 14


Sensitivity to index profile on rugate notch filter performance

Noemi Abundiz[1]; Roberto Sanginés[1]; Juan Aguila[1]; Julio Cruz[2]; Roberto Machorro[*,3]

Cátedras CONACyT-CNyN-UNAM; DGAPA-UNAM; CNyN-UNAM

Nocht filters with inhomogeneous thin films are made by several physical and chemical methods.

The core design is an alternate deposition of high and low refractive index materials. In principle,

the refractive index profile is a sinusoidal function, with maximum amplitude and minimum

amplitudes are equal to the highest and lowest refractive index, respectively. In this contribution,

we discuss the influence of the index profile of each layer on the optical performance of the filter.

We developed a computer program based on the propagation of electromagnetic waves in

continuous media with the characteristic matrix. We calculate the optical performance of a

multilayer, introducing a random variation on the rugate parameters. We conclude that index profile

is important but its shape, not a key parameter, because the reflectance of the stop band increases

with the number of layers, the stopband bandwidth depends on the min/max refractive index ratio,

and when apodization is required, the index envelope defines it. For these reasons, almost every

result with poor deposition control obtains good experimental transmittance.

Acknowledgments

This work was supported by the National Council of Science and Technology of Mexico, CONACyT

(Cátedras CONACyT, 1081; CB-2015-254494), PAPIIT-UNAM IT101017, and CONACyT-254494. J.

Cruz acknowledges his postdoctoral fellowship from DGAPA-UNAM.


AMPN - 15


Stabilization of compounds that inhibit hyperglycemic effects from Bromelia Plumieri extract supported on zeolites (FAU, MFI, HEU, BETA and MCM-41)

Miguel-Ángel Hernández [1]; Martha-Alicia Salgado [2]; Roberto Portillo [2]; Jorge-Bonfilio Mendoza [3]; David-Daniel Cadena [3]

Departamento de Investigación en Zeolitas, ICUAP, Benemérita Universidad Autónoma de Puebla, Complejo de Ciencias, 72570 Puebla, México; Facultad de

Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, México; Facultad de Ingeniería Química, Benemérita Universidad Autónoma de

Puebla, 72570 Puebla, México

The Bromelia Plumieri is a native plant from the center of Mexico and is an alternative to reduce

hyperglycemia. In this work, we report obtaining an methanolic extract from the Bromelia plumieri

plant (1:10). The extract was characterized by FT-IR and gas-mass chromatography, GC-MS. The

results of this analysis showed that there are 4 predominant compounds: Phytol (29.23%), γ-

sitosterol (6.77%), Benzoyl bromide (6.77%) and hexadecanoic acid, ethyl ester (6.47%). The extract

was stabilized in β-zeolites, MFI, FAU, HEU and an MCM-41 material. The zeolites β, MFI and FAU

were supplied by the company Zeolyst, while the natural zeolites HEU used in this work come from

Tehuacán, Puebla, Mexico. On the other hand, the material MCM-41 was a material obtained in the

laboratory under controlled hydrothermal conditions.

The nanoporous materials or supports used were characterized by: X-ray diffraction for zeolites and

low angle for materials MCM-1, EDS to chemical composition, SEM for zeolites under study and TEM

for materials MCM-41. All nanomaterials used as supports were conveniently characterized in their

nanoporosity by means of the High Resolution Adsorption of N2 at 77 K (HRADS) in the zone of

relative pressures of 10-6 to 1. All these nanomaterials have two types of porosity: primary and

secondary porosity, so it is convenient to study these porosities since it is in them that the active

phases are going to stabilize. In the zeolites in question, for steric reasons, the active phases will

stabilize in the external area and in the MCM-41 materials in the internal area. The objective of this

work is to characterize the active phases from the methanolic extract of the plant called bromelia

plumieri and its stabilizing effect in the nanomaterials proposed above. As well as the evaluation of

the porosity of the nanomaterials obtained.


AMPN - 16


Surface modification of polyethersulfone membranes by deposition of TiO2 to achieve the photocatalytic removal of the organic compounds comprising the cake in a filtration

process

V.A. Hernández-Morales*[1]; S. López Morales[2]; J.C. Durán-Álvarez [1]

Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Coyoacán, 04510, Ciudad de

México, México; Instituto de Investigaciones en materiales, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Coyoacán,

04510, Ciudad de México, México

Membrane filtration is widely used to treat wastewater and drinking water, with notable advantages

as some selectivity in the removal of contaminants, a low use of hazardous chemicals, and no need

of big spaces for operation. In contrast, the fouling of the membrane’s surface reduces the efficiency

of filtration, shortening the lifetime of the membrane and increasing the energy demand. The

formation of the cake throughout the filtration process causes the obstruction of the membrane

pores, thus using photocatalysis to remove this cake can be an approach to increase the

performance and lifetime of the membrane. This work proposes the surface modification of a

polyethersulfone membrane with nanoparticulated TiO2 (either P25 or sol-gel). Superficial

modification was performed by the self-assembly process of TiO2 on the membrane surface. A TiO2

suspension in distilled water was sonicated to obtain a dispersion; then, hydrated membranes were

and put into the TiO2 suspension for different time intervals under orbital stirring. Modified

materials were thoroughly washed with distilled water and dried at 65 °C for 40 min. The occurrence

of TiO2 on the membrane was identified via Raman spectroscopy. Changes in the superficial

structure upon TiO2 deposition were observed through SEM. Membrane’s contact angle was

calculated by the drop contour analysis, while surface area was determined by the BET method. In

photocatalysis test, high degradation of methylene blue was achieved using UV-A/visible light

irradiation. The stability of the deposited TiO2 on the membrane was assessed by determining the

leaching of Ti from the membrane via ICP-OES. In conclusion, modification of the polyethersulfone

membrane can be achieved by TiO2 deposition using a simple self-assembly method. The obtained

material was photoactive and might be used for the removal of the cake on the membrane in the

filtration processes.


AMPN - 17


femtosecond laser-induced periodic surface structure formation on thin metal films upon atmospheric irradiation

Jose Ricardo Santillan Diaz[*,1]; Abraham Wong Gutierrez[1]; Paulina Segovia Olvera[1]; Marco Antonio Camacho Lopez[2]; Santiago Camacho Lopez[1]

CICESE; UAEM

We studied the formation of laser-induced periodic surface structures (LIPSS) on thin films of

bismuth, titanium, vanadium, and gold by femtosecond laser irradiation, experimental results were

contrasted with theoretical models.

In the last few decades, LIPSS have received considerable attention due to the fact that its single-

step processing provides a reliable surface nanostructuring, which enhances some of the surface

properties. This sparks potential in several fields such as photonics, plasmonics, and eventually

industrial and medical applications. A commercial Ytterbium-doped fiber laser amplified system

(Satsuma Amplitude HP2), emitting ultrashort pulses 270 fs of durations and central wavelength at

1030 nm. All the irradiations were performed at normal incidence in atmospheric air. Optical and

morphological inspection of the formed LIPSS was performed by optical microscopy, scanning

electron microscopy, and atomic force microscopy. Micro-Raman spectroscopy was used to identify

chemical and structural changes in the irradiated regions.


AMPN - 18


Carbon Nanotubes and Graphene Promote Pyrolysis of Free-Base Phthalocyanine

Lina M. Bolívar [*, 1]; Vladimir A. Basiuk [1]; Victor Meza [1]; Elena V. Rybak-Akimova [2]; Elena V. Basiuk [3]

Instituto de Ciencias Nucleares-Universidad Nacional Autónoma de México; Departament of Chemestry- Tufts University; Instituto de Ciencias Aplicadas y

Tecnología-Universidad Nacional Autónoma de México.

The possible noncovalent functionalization of pristine single-walled carbon nanotubes (SWCNTs)

with free-base phthalocyanine H2Pc was proposed, by following the sublimation protocol used for

nanotube functionalization with unsubstituted metal phthalocyanine complexes. While we found

the preparation of target SWCNTs+H2Pc hybrid to be generally affordable, a highly undesirable side

effect of partial H2Pc pyrolysis was detected, under the conditions when this phthalocyanine is

supposed to be stable. One of the main decomposition products is phthalonitrile, as identified by

Fourier-transform infrared and Raman spectroscopy. The yield of phthalonitrile is roughly of the

order of 1%, whereas the estimates of how much phthalocyanine remained undecomposed gave

77-79%. The experiments with H2Pc sublimation in the presence of pristine multi-walled carbon

nanotubes (MWCNTs) and graphene were performed, getting the yield of phthalonitrile of 5% and

1%, and the degree of phthalocyanine preservation of about 64% and 76%, respectively. To

explanation of the physico-chemical phenomena which could cause H2Pc pyrolysis, we employed

theoretical calculations. We found that even though H2Pc molecule undergoes bending distortion

upon physical adsorption on cylindrical SWCNT sidewalls, this distortion causes an increase in the

energy of phthalocyanine macrocycle which is insufficient to provoke its thermal decomposition.

Besides that, the curvature effect cannot explain H2Pc pyrolysis in the presence of MWCNTs and

especially graphene, whose surface is essentially flat. The phenomenon which was concluded to be

a more likely explanation for the thermal behavior of H2Pc is based on its covalent attachment to

the topological defects, which contain pentagonal rings, are very common in all graphite-derived

carbon nanomaterials and capable of reacting with amines via nucleophilic addition process.

Keywords: Free-base phthalocyanine, Pyrolysis, Carbon nanotubes, Graphene; Phthalonitrile


AMPN - 19


Fabrication and characterization of optomagnetics nanoparticles for the treatment of melanoma

Claudia Alcira Espinoza González [*1,2]; Gustavo A. Hirata Flores [2]; Patricia Juárez Camacho [1]

Center for Scientific Research and Higher Education at Ensenada; National Autonomous University of Mexico

In this work we developed four magnetic rare-earth-dopedluminescent nanoparticles (MRE-NPs)

using the sol-gel method. We evaluated their physicochemical and optical properties to find the

more promising MRE-NPs that allow us a better uptake and reduce the proliferation of melanoma

cancer cells. The nanocrystalline phosphors were obtained by post-annealed of the powders at 900-

1100 °C for 3h. X-Ray Diffraction (XRD) characterization showed the crystal phase for each

nanomaterial according to the JCPDS data base reports. Nanocrystalline morphology was analyzed

by Transmission Electron Microscopy (TEM). Surface chemical groups were detected by Fourier

transform infrared spectroscopy (FTIR). The synthesized nanophosphors showed strong emission at

different wavelengths (visible and infrared) corresponding to different RE3+ ions. The amount (or

proportion) of Eu was optimized in order to obtain semi-spherical particles (80 nm diameter), and a

higher quantum yield in luminescence properties. Future experiments include testing the MRE-NP-

nanothermometer activity in melanoma cancer cells to demonstrate their potential as a new

antitumoral agent.


AMPN - 20


GROWTH OF ULTRA-THIN FILMS OF ZNO ON MAGNETO-CONTROLLABLE CORE-SHELL NANOPARTICLES

A. Ortiz-Atondo[1]; J. Tortoledo-Lafarga[2]; V. Rios-Vargas [2]; J. Lopez[3]; F. Muñoz-Muñoz[1]; J. M. Romo[2]; and H. Tiznado[2]

UABC; UNAM; CONACYT

Nowdays, a research area of great interest in nanotechnology is the development of nanoparticles

for different applications. This work focus in core-shell nanostructures synthesis based on

Co0.25Zn0.75Fe2O4 ferrite nanoparticles with superparamagnetic behavior via chemical co-

precipitation method from aqueous salt solutions in alkaline medium and coated with a silica shell

(SiO2), through the sol-gel method as removable template. ZnO ultrathin layer was growth over

SiO2 template via atomic layer deposition technique (ALD). After coating the template with ZnO, it

was removed via chemical method in order to obtain a functional material with interesting

properties that can be applied in photocatalysis, magnetic separation and drug transport.

Nanostructures were characterized by XRD, VSM and TEM in order to study the structural, magnetic

behavior, removable template morphology, particles size and ZnO coat thickness. TEM measures

for zinc-cobalt ferrites coated with silicon oxide allows to observe nanoparticles with a diameter size

distribution between 7 and 11 nm and ZnO layer thickness with approximately 30 nm. Magnetic

measures from M vs H loops, indicate a tendency superparamagnetic behavior which is a good

indicator of the high magnetization capacity. X-rays diffraction pattern allowed confirm spinel

structure formation, features this kind of ferrite. This results opens the possibility to use this

functional materials in different nanotechnology fields.


AMPN - 21


Hybrid diamagnetic-ferromagnetic response of SiO_2 opals with Ni nanoparticles

Carlos Ernesto Ávila-Crisóstomo [1]; Marina Shelyapina [2]; Anna Shmyreva [3,2]; Umapada Pal [1]; Felipe Pérez-Rodríguez [*,1]

Benemérita Universidad Autónoma de Puebla, Mexico; Saint-Petersburg State University, Russia; Charles University, Czech Republic

The magnetic properties of artificial SiO_2 opals infiltrated with nickel nanoparticles are studied

both experimentally and theoretically. The response of the composite has a ferromagnetic region

followed by a diamagnetic one when the magnitude of the external magnetic field is increased.

These characteristics are not observed in most cases due to the low magnetic response of the

elements involved. Diamagnetism in the artificially synthesized opals was observed, having a

negative magnetic susceptibility of the order of 10^-5. Also theoretical calculations were

performed on the basis of the Landau-Lifshitz-Gilbert (LLG) equation, taking into account the dipole-

dipole magnetic interaction between Ni nanoparticles, as well as the diamagnetic response of the

host material. Enhanced diamagnetic response of the magnetic nanocomposite is experimentally

observed and theoretically explained as the effect of the local magnetic field on each Ni

nanoparticle.


AMPN - 22


Magnetron sputtering of titanium and graphite, with and without magnets, using DC, P-DC and RF

S. MUHL*[1]; S.E.RODIL [1]; L.E. SANCHEZ-BALANZAR [1]; E. CAMPS[2]

1 IIM-UNAM; ININ

Magnetron sputtering has been used extensively to deposit thin films for a very broad range of

applications. Magnetrons use a magnetic field close to the cathode to trap electrons and produce

an increased ionization of the gas. This increased plasma density allows sputtering at lower

pressures, higher sputtering rates and greater bombardment of the deposit. The optimal magnetic

field strength depends on a combination of the sheath width and the target voltage. If the electron

cyclotron radii are significantly less than, or much larger than, the sheath then little increase in the

ionization is produced. It has been proposed that when RF or pulsed DC (P-DC) are used the

overvoltage associated with restarting the plasma in each cycle, plus the varying target voltage

means that the magnetron has little effect, i.e. that the magnetic field is only effective for a small

part of each cycle. To study this idea, we have prepared carbon and titanium thin films by low

pressure argon magnetron sputtering, with and without the magnets, using the same experimental

conditions, but with DC, RF or 250 kHz P-DC. Without the magnets the maximum useable plasma

power was less than 80 W for the RF and 200 W for the P-DC, using the graphite target, and 300 W

RF and 200 W P-DC using the titanium target. Applying higher powers resulted in very unstable

plasmas and/or plasma extinction. The deposition rates without the magnets were about half that

of when they were present, independent of the target or type of high frequency excitation, and the

DC deposition rates were 2 to 3 times the high-frequency rates. The thickness uniformity, hardness

and adhesion of the films to the glass substrates were strongly dependent on the type of electrical

power used.


AMPN - 23


Understanding Bi3Ge4O12 electrochemical behavior as Li-ion anode

Jassiel R. Rodriguez [1,*]; Carlos Belman [2,3]; Sandra A. Aguirre [3]; Sergio Aguila [3]; Yanning Zhang [4]; Hongxian Liu [4]; Vilas G. Pol [1]

Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, United States; Centro de investigación y de educación superior de ensenada,

Ensenada, BC 22800, Mexico; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, BC 22860, Mexico; Institute of

Fundamental and Frontier Science, University of Electronic Science and Technology of China, Chengdu 610054, China

Ex-situ XRD, DTF calculation and systematic electrochemical experiments were performed to gain

insight into the conversion and alloying reaction of Bi3Ge4O12 as promising anode for Lithium ion

batteries. Ex-situ XRD permitted to identify the phase transitions that occurs inside Bi3Ge4O12

anode during (de)lithiation processes, revealing an irreversible Bi3Ge4O12 phase transformation to

a mixture of oxides, Bi2O3 and GeO2, after its first (de)lithiation cycle. DFT calculation indicated that

Li-ions prefers octahedra sites surrounded by oxygens and Bi2O3 is more easily lithiated than GeO2.

The electrochemical evaluation of Bi3Ge4O12 exposed an continuous loss of capacity due to the

inactivation of the conversion and alloying reaction related to bismuth as result of the vanishing of

some active species, indicating that the specific capacity delivered by Bi3Ge4O12 after 100 cycles

depends meanly of the (de)lithiation reactions associated to germanium.


AMPN - 25


Ag nanoparticles embedded in a magnetic composite for magnetic separation applications

J. López [ 1, *]; J.M. Aguilar-Torres [ 2,3]; L. A. Arce-Saldaña [ 2,4]; A. Portillo-López [ 3]; S. González-Martínez [ 3]; J. S. Betancourt [ 5,6]; M.E. Gómez [ 5]; E. Vargas-Viveros [ 3]; D. Dominguez [ 4]; H. Tiznado

[ 4]; G. Soto [ 4]

CONACYT – Centro de Nanociencias y Nanotecnología (CNyN); Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE); Universidad

Autónoma de Baja California (UABC), Facultad de Ingeniería, Arquitectura y Diseño Facultad de Ciencias; Universidad Nacional Autónoma de México (UNAM),

Centro de Nanociencias y Nanotecnología (CNyN); Universidad del Valle, Thin Film Group, Physics Department; Center of excellence on novel materials, CENM

This work is focused on the preparation of a multifunctional compound consisting of silver

nanoparticles (AgNPs) embedded in a matrix of amorphous carbon previously loaded with Fe3C

magnetic particles. The objective is to use the antibacterial properties of the AgNPs for

environmental purposes, in such a way that the AgNPs can be recovered by physical means

(magnetic separation). The synthesis method was direct from ferrocene, silver nitrate and

polyethylene glycol placed in a reaction tube and pyrolyzed by a plasma produced under vacuum

conditions. For this, a conventional microwave oven was used. The compound obtained is a black

powder, with similar consistency to graphite, but it responds strongly to the application of magnetic

fields. The material was thoroughly characterized by X-ray photoelectron, energy-dispersive X-ray

spectroscopies; transmission and scanning electron microscopies; X-ray diffraction, as well magnetic

characterizations using a vibrating sample magnetometer. The material showed a homogeneous

dispersion of metal particles in the carbon matrix. We conclude that the combination of magnetic

and antibacterial properties makes this material interesting for several applications through the use

of magnetic separation protocols.

Keywords: core-shell magnetic nanostructures; Fe3C; activated carbon; magnetic separation;

wastewater treatment; antibacterial material.

Acknowledgements

This work was partially supported by project UABC-PTC-595 PRODEP-SEP, México and Dirección

General de Asuntos del Personal Académico DGAPA-UNAM - by, through research projects: PAPIME

PE100318, PE101317, PAPIIT IA 101018, IN 112117, IN 110018 and IA 103117, FORDECYT - CONACYT

272894 and the Center of Excellence on Novel Materials CENM, Universidad del Valle, Colombia.

The technical assistance of I. Gradilla, F. Ruíz, E. Flores, M. Estrada, H. Borbón and E. Aparicio are

gratefully appreciated.


AMPN - 26


Berry phase and spin Hall current response of spin-orbit coupled systems

Daniel A. Muñoz* [1];Jesús A. Maytorena [2]

Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California,

México;Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 2681, Ensenada, 22800 Baja California, México

We study the Berry phase and its influence on the spin Hall conductivity in a two-dimensional system

with generic k-linear spin-orbit (SO) coupling. These quantities were analytically calculated including

a normal-to-the-plane component of the SO vector field in the Hamiltonian, in contrast to recent

reports. Within the linear response theory, the (static) spin conductivity tensor is obtained by

employing a conserved spin current, composed of the conventional and spin-torque currents.

Having derived a SO Hamiltonian with Rashba and linear-in-momentum Dresselhaus couplings for

an arbitrary crystal orientation, we explore a possible universal connection between the spin Hall

current response and the Berry phase for a given sample growth direction, besides the well known

[001] case.

We want to thank CONACyT for the financial support during the elaboration of this work.


AMPN - 27


Biopolymer-zinc oxide dressings for wound healing applications

Daniela G.Castro-Bertin[*,1]; Johanna Bernáldez-Sarabia[2];Lesly S. Gomez-Aparicio[3];Alexei Licea-Navarro[2]; Priscy A. Luque-Morales[1]; Ana B. Castro-Ceseña[2];

UABC; CICESE;ITT

Biopolymers such as alginate and gelatin have essential characteristics such as, high

biocompatibility, non-toxicity and biodegradability for being used as biomaterials in wound healing

process. For example, 3D porous structures may be prepared using gelatin, which allows cell

proliferation. While alginate based-materials are used for their hemostatic properties. Therefore, in

the present work, wound dressings based on these biopolymers, and incorporating zinc oxide (ZnO)

nanoparticles (20nm diameter) were developed. Addition of ZnO nanoparticles (2 mg/ml) provided

antioxidant capacity 25% (oxidation inhibition) to the dressings. Gelatin- and alginate-based

materials showed antimicrobial activity against Escherichia coli after incorporation of 5 mg of ZnO

to the dressings. Analysis by Scanning Electron Microscopy showed that both dressings, i.e. gelatin-

or alginate-ZnO materials, are porous (100 – 200 nm pore size). In this work, porous and flexible

materials, with antimicrobial and antioxidant activity were developed. Based on these results, the

obtained biomaterials may be a good choice for wound healing applications.


AMPN - 28


CHARACTERIZATION OF MoS2-CNx MULTILAYER COATINGS BY NANOINDENTATION

Aime Gutiérrez-Peralta [1*]; Carlos Alberto Ávila Herrera [1]; Joel Moreno Palmerín [2]; Jorge Morales-Hernández [3];Gustavo Zambrano [4]; José Martín Yáñez-Limón [1]

CINVESTAV Unidad Querétaro; Universidad de Guanajuato; CIDETEQ;Centro de Excelencia en nuevos materiales

Molybdenum Disulphide (MoS2) and amorphous carbon nitride (CNx) are known as solid lubricants

and widely used in engineering applications. The sputtered MoS2 coating has low coefficient of

friction and low wear rate in dry air and vacuum environment; however it has shown a degradation

of tribological properties in moisture environment, instead amorphous CNx is hard and chemical

inert material. The mixture of MoS2 and CNx layers will possibly improve their performance against

wear in environmental conditions.

In this work a multilayer arrangement with alternating layers of CNx and MoS2 are suggest achieving

a low friction coefficient and wear resistant due that both materials have present good self-

lubrication. In addition, several studies reported that multilayer coatings have better properties

than single layers.

The MoS2 layer was prepared by D.C pulsed sputtering technique in inert atmosphere (100% Ar),

after a CNx layer was grown by reactive DC sputtering in a 90%-10% mixture atmosphere of Ar and

N2, respectively. This period was repeat from 1 to 5 times, the multilayer coatings were deposited

a stainless steel substrates; these were analyzed by Field emission scanning electron microscopy

(JEOL 7610F), and atomic force microscopy (Park systems AFM) to characterize the morphology and

topography.

The multilayer coatings were investigated by AFM nanoindentation and IBIS nanoindentation

system using a Berkovich indenter with a force resolution is nN and μN, respectivaly. The

nanoindetation test determine hardness and elastic modulus. The values mechanical properties of

multilayer coatings can be related to performance as solid lubricant.


AMPN - 29


Cathodoluminescence and electrical conduction mechanism on single ZnO nanobelts

Karime C. [*1,2]; Manuel H. [2]; Eduardo M. [2]; Ignacio R. [3]

Posgrado en Ciencia e Ingeniería de Materiales, Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología Apdo. Postal 2681,

Ensenada, 22800 B.C., México.; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 2681, Ensenada, 22800 B.C.,

México.;Centro de Graduados, Instituto Tecnológico de Tijuana, Tijuana, 22414 B.C., México.

Currently, the main theme in nanoscience and nanotechnology is to develop simple methods to

synthesize ultrathin nanostructures being able to manipulate these materials and exploring novel

electrical properties to enable high-density device integration taking advantage of the

confinement properties. ZnO nanostructures are attractive due to their variety of morphologies and

availability of low-cost and straightforward processing such as Thermal Evaporation (TE) technique.

In this work, we report the optimization of ZnO nanobelts

synthesis by TE and demonstrate that its defect structure dominates their electrical conductivity

properties. The synthesis of ZnO nanobelts took place in a horizontal TE furnace onto ZnO ceramic

substrates at 600°C, by using N2 as a carrier gas with a flow between 3.0 -3.2 sccm.

Cathodoluminescense (CL) measurements showed two bands centered at 3.2 and 2.5 eV, attributed

to the ZnO band edge and oxygen vacancy-related emissions, respectively. Scanning Electron

Microscopy (SEM) images revealed the presence of pinholes and folds on the surface of the

nanobelts, which was confirmed using Atomic Force Microscopy in Conducting mode (C-AFM).

Leakage current (LC) images obtained with a forward bias of 5V reveal the generation of signal

contrast at some pinholes and grain boundaries regions.

I-Vcurves acquired for the electrical conduction through the cross-section of the nanobelts showed

a Poole-Frenkel mechanism. Electrical conduction along of individual ZnO nanobelts was studied by

using a micromanipulator, coupled in the vacuum chamber of the SEM, composed of two In/W

microelectrodes. I-V curves acquired at bias lower than 13 Volts confirmed a Poole-Frenkel electrical

mechanism.

Several I-V curves obtained at bias between -10 and 10 V permitted us to calculate the sheet

resistivity of nanobelts, recording values between 5 to 7 Ω-cm.


AMPN - 30


CdS films as transport layer deposited by a novel PCD technique for perovskite hybrid solar cells

S. Meraz Dávila [a,b,]; J. Saviñon de los Santos [b]; R. Ramírez Bon [c]; Ma. de la Paz Cruz Jáuregui [b]; J. L. Heiras Aguirre [b.

Centro de Nanociencias y Nanotecnología- UNAM; Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California; Centro de Investigación

y de Estudios Avanzados del I.P.N

For years semiconductor materials have been applied in solar cells, in general for optoelectronic

devices; these are based on the photovoltaic phenomena which consists in the efficient absorption

of light, charge separation of electron-hole pair and the fast transport and extraction of charge

carriers to avoid recombination processes. Few years ago, silicon-based technologies had been

promising, until efficiencies were greater than 20% obtained from devices with hybrid organic-

inorganic architectures based on perovskites used as light absorber components, which offer easy

processing, high efficiencies and low costs. The configuration of the perovskite is of the ABX3 type,

where A (mainly CH3NH3), B (Pb or Sn), X (Cl, Br, I). One of the traditional architectures of hybrid

organic-inorganic devices, based on perovskites is the addition of a mesoporous base (mostly used

titanium dioxide) and a hole transport layer (2,2´,7,7´-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9-

bifluorene (spiro-OMeTAD)) which have been obtained efficiencies greater than 15%. It has been

observed that in combination with perovskite, the electron transport layer plays an important role

in maintaining the stability of the device. In this work we analyzed the deposit of Cadmium sulfide

(CdS) films as an electron transport material in the perovskite-based solar cell. CdS was grown by

photochemical deposition technique from an aqueous ammonia-free solution at room temperature.

CdS despite being highly used in thin film solar cells, has not been explored in perovskite-based

devices, which make it suitable due of its optimal feature because of its charge carriers’ high

mobility, low cost, fast and simple via process and scalable flexible solar cell applications.


AMPN - 31


Design and synthesis of anti-reflective filters

Cruz L. C.[1,*];Abundiz N.[2];Sanginés[2];Águila J.[2];Cruz J. C.[2];Machorro R.[2]

Universidad Autónoma de Baja California, Carretera Transpeninsular Ensenada - Tijuana No. 3917;Centro de Nanociencias y Nanotecnología-Universidad Nacional

Autónoma de México, Km 107 Carretera Tijuana-Ensenada

The use of cell phones, televisions, computers, lenses, windows, which are made up of different

components such as transistors, processors, coatings, etc., has a great impact on the daily life of

man. The thin films coatings have different properties such as hardness, color, transparent

conductive layers or antireflective properties.

The antireflective filters are usually used in eyeglasses, telescopes and solar cells. Currently, in the

industry it is important to improve the performance of this kind of coatings. In this work, the design

and synthesis are presented using materials such as silicon dioxide (SiO2), aluminum oxide (Al2O3),

aluminum nitride (AlN) and zinc oxide (ZnO), obtaining a transmission greater than 96 % at 505 nm.

Subsequently, the material layers were synthesized on BK7 glass through the sputtering technique.

The optical characterization of each layer was by in-situ ellipsometry and plasma spectroscopy, in

order to determine the optimal conditions of growth of the layers and its reproducibility.

Acknowledgments: This work was supported by the National Council of Science and Technology of

Mexico, CONACyT (CB-2015-254494, PAPIIT-UNAM IT101017)

References:

1. Depla, D., Mahieu, S., & Greene, J. E. (2010). Sputter deposition processes. En Handbook of

Deposition Technologies for Films and Coatings (Third Edition) (pp. 253–296). Elsevier.

2. Hernandez Utrera, O., Abundiz-Cisneros, N., Sanginés, R., Diliegros-Godines, C. J., & Machorro, R.

(2018b). Cleaning level of the target before deposition by reactive direct current magnetron

sputtering. Thin Solid Films, 646, 98–104.

3. Larouche, S., & Martinu, L. (2008). OpenFilters: open-source software for the design,

optimization, and synthesis of optical filters. Applied Optics, 47(13), C219


AMPN - 32


Development of aluminum-based Low-Emissivity optical filters using double cannon sputtering technique

R. Rodríguez-López[*,1]; N. Abundiz-Cisneros [3]; R. Sángines de Castro [3]; M. Peralta-Arriola [1]; J. Cruz-Cárdenas [2]; R. Machorro-Mejía [2]

CICESE; UNAM-CNyN; CONACyT

Nowadays, windows with Low-Emissivity (Low-E) optical filters technology in buildings reduces

thermal interchange with the environment, saving up to 30% of the energy used to maintain the

building's temperature. Commercial designs of these filters use silver, which is expensive and also

loses its properties when it gets in contact with the atmosphere, or when moisture filtrates towards

the thin silver layer (Ando, 1999).

This work aims to develop a design that uses aluminum instead of silver to obtain a cheaper, efficient

and durable Low-E filter. The theoretical filter was simulated using the software ‘Open Filters'

(Martinu, 2008) based on the propagation of electromagnetic waves in continuous media, using

different types of materials. The Low-E filters were simulated varying the layer thickness values and

the stacking order, searching for the best theoretical efficiency (high transmittance >80% in the

visible range and high reflection in the infrared) (Leftheriotis & Yianoulis, 2012). The synthesis of the

best aluminum-based Low-E filter was performed in a double cannon sputtering; the whole filter

was synthesized without opening the chamber, in order to avoid the filter interaction with the

atmosphere, preventing any layer oxidation from the stack. Plasma spectroscopy and ellipsometry

were applied in situ, to find the optimal deposition conditions and also for controlling and

monitoring the process looking for its reproducibility.

Acknowledgments


(CB-2015-254494, PAPIIT-UNAM IT101017). J.Cruz acknowledges his postdoctoral fellowship from

UNAM, R.Rodriguez-Lopez and M.Peralta-Arriola acknowledges their scholarship from CONACyT

References

M. Miyazaki, et al. Journal of Non-Crystalline Solids, vol.178, pp.245-249, 1994

L. Martinu, et al. Applied Optics, vol.47, no.13, pp.C219-C230, 2008

Leftheriotis, et al. Solar Energy Materials & Solar Cells, vol.58, pp.185-197, 1999


AMPN - 33


Development of field effect transistors with pseudo-MOS structure based on GaN synthesized by CVD

O. E. Paredes-Gallardo[*,1]; A. Ramos-Carrazco[1]; R. García-Gutiérrez[1]; D. Berman-Mendoza[1]; H. J. Higuera-Valenzuela[1]; O. E. Contreras[2]; G. A. Hirata[2]

Departamento de Investigación en Física, Universidad de Sonora (UNISON), Blvd. Luis Encinas y Rosales s/n, Hermosillo, Sonora, C.P. 83000, México; Centro de

Nanociencias y Nanotecnología (CNyN), Universidad Nacional Autónoma de México, Km. 107 Carretera Tijuana-Ensenada s/n, Ensenada, B.C., C.P. 22800, México

In this work, the fabrication and electrical characterization of FET transistor with Ψ-MOSFET

structure based on GaN as active layer are presented. The transistor fabricated consists of a

structure GaN/SiO2/n-Si/AlGate. In order to characterize the response of the MOS device, different

channel lengths with a constant width of 1 mm were implemented. The ID-VDS curves with different

gate voltages were measured by means of a semiconductor characterization system. The FET

transistor with Ψ-MOSFET structure shows a mode operation based on the depletion behavior. A

decrease of the Drain current in the saturation region was associated with the modulation of the

carriers on the channel. The GaN films were deposited on silicon substrates with a low resistivity

surface by the CVD technique at 950 °C.


AMPN - 34


Effect of La3+/Sr2+ ordering on the magnetic properties of La2/3Sr1/3MnO3 by first principles calculations

H´Linh H´Mŏk [*,1,2]; Espiridión Martínez Aguilar [1,2]; Jordi Ribas Ariño [3]; Jesús María Siqueiros Beltrones [2]; José Luis Sánchez Llamazares [4]; and Oscar Raymond Herrera [2]

Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Tijuana-Ensenada No. 3918, Zona Playitas,

Ensenada 22860, Baja California, México; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, Ensenada 22860,

Baja California, México; Departament de Ciència de Materials i Química Física and IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain;

Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José 2055, Col. Lomas 4ª sección, CP 78216, San Luis Potosí, S.L.P., Mexico.

The La2/3Sr1/3MnO3 (LSMO) material is a promising candidate for Spintronics as a source of spin-

polarized electron current. To date, many theoretical works have been focused on describing the

physical properties of La1-xSrxMnO3 with cubic and/or tetragonal perovskite structure. However, a

detailed discussion on the effect of the Sr distribution on the magnetic properties of LSMO is still

missing in the Literature. In this work, using DFT+U formalism, we investigate the effect of the order-

disorder in the A-site occupation by La3+ and Sr2+ on the stability of the ferromagnetic order in

LSMO bulk with 𝑅3𝑐 symmetry. For this purpose, we employ structural models corresponding to

rhombohedral R3c symmetry consisting of 120 atom supercells constructed according to the precise

stoichiometry of the compound. Two configurations, describing randomized and ordered

occupation of the La3+ and Sr2+ ions, are evaluated. The electronic structure of these configurations

has been studied by means of an analysis of their density of states, band structure, electron density

and electron localization function. We have demonstrated that the ferromagnetic arrangement of

the LSMO with La3+ and Sr2+ ions randomly distributed is more stable than that with an ordered A-

site occupation. We find that with the random configuration, is not possible to distinguish between

Mn3+ and Mn4+ ions, thus favoring the double-exchange mechanism, which in turn is enhanced by

the high degree of covalence in the Mn-O bonds near the Fermi level between the spin-up Mn-eg

orbitals with the O-p orbitals.


AMPN - 35


Effect of the Hydrogen flow: Electrical and optical properties of SRO films with Si-ncs deposited by HFCVD

Diana E. Vázquez Valerdi*[1]; Zaira Hernández Simón[1]; Gabriel Mendoza Conde[1]; Jose A. Luna López[1];

Benemérita Universidad Autónoma de Puebla

In the present work, the effect of the hydrogen flow on the optical and electrical properties of silicon

rich oxide (SRO) films is reported, which were deposited by hot filament chemical vapor deposition

(HFCVD) technique. The SRO films were realized with three different hydrogen flows: 25, 50 and 75

sccm, the others deposition parameter were fixed. Structures MOS-like were fabricate with SRO

films, the devices MOS-like were labeled as A, B and C respect to hydrogen flows 25, 50 and 75 sccm,

correspondingly. The contacts of the upper and lower devices were made of aluminum deposited

on a high vacuum evaporator; the area of these was of 0.00785 cm-2. The optical results of the SRO

films show transmittance spectra bigger than 70 % in the visible range and the absorption edge

exhibits shift to low wavelength, when the hydrogen flow decreases; which in turn indicates a

decrease in the Si excess as well as an increase of the optical energy band gap; this affirmation can

be related with previous results obtained by XPS. The SRO films show broad Photoluminescence (PL)

spectra with main peaks at 688, 750 and 825 nm, where the PL intensity decreases as the hydrogen

flow increase, which are related with the increased in the silicon excess as silicon nanocrystals (Si-

ncs), which is confirmed with HRTEM micrographs. The structures MOS-like show an interesting

photovoltaic effect due to SRO films with Si-ncs. These effects are obtained when devices were

illuminated with white, UV-short and UV-large light. These photovoltaic characteristics were used

to obtain the photosensitivity, responsivity and quantum efficiency.


AMPN - 36


Efficiency of a multilevel quantum heat engine with toroidal geometry in a modified Carnot cycle.

Rosales O. [1]; Iglesias P. [1]; Villareal R.[2]

Facultad de Ciencias, Universidad Autónoma de Baja California; Facultad de Ingeniería, Arquitectura y Diseño, Universidad Autónoma de Baja California

A classical heat engine is a device that extracts energy from a high temperature heat source, it

generates work with an amount of this energy and the rest is release into a low temperature drain.

It is well known that the highest possible efficiency of a heat engine is reached by following the

Carnot cycle. Many systems and processes have been studied in order to increase the efficiency of

a heat engines, it was with the study of quantum systems that Quantum Heat Engines (QHE) have

been theoretically proposed. In a QHE it is consider a single particle confined by a quantum well

which walls play the role of a piston by moving in and out. In this work we introduce multiple energy

levels that are available to the confined particle in a two-dimensional square potential well that has

periodicity in both sides of the well, thus the space where the particle moves can be considered as

a torus.

Following a modified carnot cycle, in which the well is not fully expanded during the first isothermal

process but equally expanded, as the case for a normal carnot cycle, during the adiabatic process,

we find that the efficiency of the QHE depends directly on the energy levels used during the whole

cycle. These results enable us to extend our understanding about the effects of spatial periodicity

and quantum superposition on the efficiency of a QHE.

References.

Bender, C. M., Brody, D. C., & Meister, B. K. (2000). Quantum mechanical Carnot engine. Journal of

Physics A: Mathematical and General, 33(24), 4427.

Quan, H. T., Liu, Y. X., Sun, C. P., & Nori, F. (2007). Quantum thermodynamic cycles and quantum

heat engines. Physical Review E, 76(3), 031105.

Quan, H. T., Zhang, P., & Sun, C. P. (2005). Quantum heat engine with multilevel quantum systems.

Physical Review E, 72(5), 056110.

Latifah, E., & Purwanto, A. (2011). Multiple-state quantum carnot engine. Journal of Modern

Physics, 2(11), 1366.

Zwiebach, B. (2004). A first course in string theory. Cambridge university press.


AMPN - 37


Electroluminescence in MOS devices with SRO films deposited by the HFCVD technique

H. P. Martínez-Hernández[1,3]*; J. A. Luna López[1]; K. Monfil Leyva[1]; G. García Salgado[1]; R Ordoez-Flores[3]; R. Ramírez Amador[1]; J. A. D. Hernández-de-la-Luz[1]; Z. J. Hernández Simón[1].

Benemérita Universidad Autónoma de Puebla (BUAP); Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE); Instituto Tecnológico de Apizaco (ITA)

Electroluminescence (EL) and optical characterizations of Metal Oxide Semiconductor (MOS)

structures with Indium tin oxide (ITO) and gold used as contacts, constituted by silicon-rich oxide

(SRO) nanometric films are reported in this work. The monolayers (SRO25 and SRO100) and bilayers

(SRO25/100 and SRO100/25) films were obtained by hot filament chemical vapor deposition

(HFCVD) technique, on substrates of Silicon (Si) and Quartz (Q). The hydrogen fluxes used for the

deposit were 25 and 100 sccm. Both monolayers and bilayers after the deposit were thermally

treated. Different characterization techniques were used. Ellipsometry and Scanning Electron

Microscopy (SEM), was used to obtain and compare the thickness of the SRO films, SRO25 309.65

nm and SRO100 275.65 nm. Fourier transform infrared (FTIR) spectroscopy showed greater

intensity in absorption and shifts at higher wave numbers, after thermal annealing, and the

disappearance of the characteristic hydrogen peaks, indicating a better stoichiometry. Using the UV-

Vis technique, the energy of the gap (Eg) SRO films were obtained, with the purpose of obtaining

the Si-ncs diameter. Which was corroborated with the analysis of photoluminescent (PL) and High-

resolution Transmission Electron Microscope (HRTEM). With the different PL intensities and shift to

higher wavelengths after annealing thermal of SRO films, was calculated the Eg to obtain the Si-ncs

diameter and corroborate it with the HRTEM of 4.4 0.7 nm. The measurement in I-V curves in the

first voltage sweeps made to pristine devices, show instability in measured current values, after

reaching a certain value of the applied electric field, the IV curves are stabilized. I-V curves seem to

show a Poole-Frenkel conduction’s mechanism. Electroluminescence spectra from all our SRO

structures start at low current of 60uA and at a voltage greater than 28V to turn on few bright dots,

up to voltages greater than 150 V where the highest number of bright dots is observed.


AMPN - 38


Electronic transport through deformed benzene nanowires

Daniel García Flores* [1]; Diego Osvaldo Ochoa de la Cruz* [1]; Priscilla Elizabeth Iglesias Vázquez [1]; Rubén César Villarreal Sánchez [2];

Facultad de Ciencias, UABC; Facultad de Ingeniería, Arquitectura y Diseño, UABC;

Recent advances in nanotechnology have made possible the fabrication of structures whose

dimensions are in the nanometric regime (Datta, 1997). These structures can be made with the use

of organic molecules as components which can replicate electronic devices at the mesoscopic scale.

One common synthetized device is the nanowire (Poarth et al, 2000), used for charge and

information transport. We model this system using the tight binding formalism, solving for the

atomic and bond energies with the Greenian matrix version of the discretized Schrödinger equation.

Then, we calculate the system transmission with the help of the Lippmann-Schwinger scattering

theory. Following the electronic transport model proposed by Sulston and Davison (2015) for

benzene nanowires, a parameter that represents deformations in the system was introduced. The

purpose of this was to see whether the transmittance resonances conservate and in which energy

intervals, if the system is strained. In this work, we show how the Transmittance-Energy profiles

varies depending on the type of strain applied to the system, these being increments or decrements

in the hopping energy. We found optimized intervals where a resonance maintains despite a

deformation and intervals where a gap is created, reflecting the semiconductor qualities of the

system. The latter being important for the fabrication of electronic components.

References:

Datta, S. (1997). Electronic Transport in Mesoscopic Systems. Cambridge University Press.

Porath, D., Bezryadin, A., de Vries, S., Dekker, C. (2000). Direct measurement of electrical transport

through DNA molecules. Nature 403, 635-637.

Sulston, K. & Davison, S. (2015). Transmission of Renormalized Benzene Circuits.

arXiv:1505.03808v1


AMPN - 39


Evaluation of magnetite nanoparticles for the degradation of recalcitrant reclaimed water

Enrique Contreras* [1,2];David Dominguez [2]; Hugo Tiznado [2]; Gabriel Alonso-Núñez [2]; Oscar E. Contreras [2]; Mercedes T. Oropeza [3]; José M. Romo-Herrera [2]

CICESE; CNyN-UNAM; TecNM

Advanced oxidation processes (AOPs) are emerging as viable remediation technologies for water

contaminated with recalcitrant organic pollutants. The AOP’s produces hydroxyl radicals through

chemical pathways such as the Fenton reaction, requiring the addition of H2O2 as a precursor, for

the oxidation of recalcitrant pollutants in the water [1].

Magnetite has been documented for its ability in the formation of Fenton reagent besides its ability

to absorb inorganic contaminants and heavy metals, becoming the magnetite as a viable solution

for water contaminated with recalcitrant organic pollutants. [2].

In this work, we explored the stability of magnetite nanoparticles (Np Fe3O4) when using different

stabilizing agents (Chitosan and CTAC) assisted by ultrasound. The obtained dispersions were tested

for the removal of a target molecule (Amaranth Red) tracking it by UV-Vis spectrometry. The

concentration of hydrogen peroxide as a precursor, pH and the sunlight effects were evaluated.

Additionally, we analyzed our magnetite dispersions for the removal of recalcitrant pollutants from

Tijuana’s city wastewater provided by CESPT. The degradation tests were tracked by fluorescence

spectroscopy, total organic carbon and chemical oxygen demand.

Finally, we fabricated a buckypaper using the iron oxide nanoparticles anchored to CNx, looking

forward to a functional material which could enhance the electrochemical promotion of the Fenton

reaction, a key reaction for wastewater treatment.

Acknowledgements: We thank financial support by UNAM DGAPA-PAPIIT IN105719, IN107715,

IN112117 and DGAPA-PAPIME PE108319, PE101317, PE101517; Conacyt through Fordecyt 272894.

We thank technical assistance by Israel Gradilla, Francisco Ruiz, Eloisa Aparicio, Jaime Mendoza, and

Eric Flores.

[1] Advanced Oxidation Processes for Wastewater Treatment: Emerging Green Chemical

Technology., ed. S.C. Ameta, R. Ameta, Academic Press, 2018.

[2] Usman, M. etal. (2018). Chemical reviews, 118(7), 3251-3304.


AMPN - 40


Fabrication of a photodiode based on ZnO nanowires

T Valenzuela[*,1]; M Herrera[1]

Centro de Nanociencias y Nanotecnologia, UNAM, Ensenada, 22800-Baja California, Mexico

We present a cathodoluminescence (CL) study of the distribution of point defects and the electrical

conduction mechanism in the ZnO nanowires of a Schottky photodiode. The device was fabricated

by synthesizing the nanowires by thermal evaporation between two Au electrodes, while applying

an AC electric field to induce alignment of the nanowires. Results demonstrate that, besides the

alignment, the applied electric field inhibited the formation of the native defects associated with

the well-known ZnO green emission. Furthermore, CL spectra obtained at different zones of the

photodiode revealed an energy shift for the band-edge emission, which was assigned to changes in

the relative intensity of two components centered at 3.23 and 3.27 eV attributed to donor-acceptor

pair (DAP) and free electrons-acceptor (FA) transitions, respectively. Proposing the zinc vacancies

(VZn) as acceptor centers. Electrical conduction measurements of the device under dark and UV

illumination revealed tunneling and thermionic emission as charge transport mechanisms. We

observed a strong photo-response of the device under UV illumination, and obtained current values

ten times higher than those observed without it, which confirms high sensibility to detect UV

radiation.


AMPN - 41


First-Principles Study of Spontaneous Polarization in BiFeO3 doped with Lanthanum

E. Martínez-Aguilar[1,2]; H´Linh H´Mŏk [1,2] ; F.Herrera-Rodríguez [1,2]; and J. M. Siqueiros [2]


Ensenada, Baja California, Mexico, 22860 ;2Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de Mexico AP 14, Ensenada, Baja California,

Mexico, 22860

One of the most natural methods to improve the structural properties of BiFeO3, is through doping

with Lanthanum. However, there is still discussion about the mechanisms involved to modify

polarization, magnetic moment and structural properties. In this work, using the density functional

theory DFT, we study the effects of doping with lanthanum, randomly, on the primitive cell of BFO;

such effects are manifested through the analysis of symmetry and its variations when the amount

of dopant is increased. Likewise, the deformations of the octahedra occur whenever the increase in

doping, affecting the hybridization between O-2p and Bi-6s orbitals of BFO. To identify this case, the

anisotropy of the Fe-O6 bonds in the direction [111] of the polarization is included as well as the

calculation of electron function localization (ELF); which describes the mostly ionic behavior of BFO.

However, the calculations do not show changes significant on the magnetic properties and the

Polarization finds a minimum and a maximum during impurification.


AMPN - 42


Gelatin-based bioactive dressings for wound healing applications

Lesly S. Gomez-Aparicio [1]; Johanna Bernáldez-Sarabia [2]; Daniela G. Castro-Bertin [3]; Alexei Licea-Navarro [2]; Ana B. Castro-Ceseña [2*.

Instituto Tecnológico de Tijuana, ITT; Centro de Investigación Científica y de Investigación Superior de Ensenada, CICESE; Universidad Autónoma de Baja California,

UABC

In this work, gelatin-based materials were prepared and characterized for their potential application

as wound dressings. Gelatin (Gel) is a natural, biocompatible and biodegradable polymer. The use

of gelatin has resulted in the improvement of cell attachment, which allows the connection and

signaling of cells, which makes gelatin a very attractive biomaterial. However, gelatin matrices have

a low stability in aqueous medium. To overcome this drawback, the polymers of 2-hydroxyethyl

methacrylate (HEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA), were

incorporated to improve the stability in aqueous medium of the dressings. The obtained

biomaterials were cross-linked by heat-dehydration at 140±2 °C and 88 kPa of vacuum. N-

acetylcysteine (NAC) was added, at different concentrations, as the bioactive compound to promote

healing. The effect of adding HEMA-PEGMA to the gelatin matrix signicantly increased the porosity

of the dressings. The addition of 25 μg/ml of NAC to the Gel-HEMA-PEGMA dressings, increased the

antioxidant capacity from 5.14 to 7.65 nmol TEAC/mg dressing, and the anti-inflammatory activity

(related to NO removal) from 0 to 8.23 ±1.76%. These dressings had a greater degree of swelling in

the ionic environment of a chronic wound than in water, this is favorable because a humid

environment around the wound accelerates healing and reduces the risk of bacterial infections. The

dressings of Gel-HEMA-PEGMA and Gel-HEMA-PEGMA-NAC showed 35±3% degradation after 20

days of contact with an aqueous medium. Our results showed that Gel-HEMA-PEGMA-NAC

biomaterials have a potential for applications in wound healing.


AMPN - 43


Low emissivity optical filters based on copper

D.G. Mejia. [1,*]; N. Abundiz-Cisneros. [2]; R. Sangines. [2]; J. Cruz. [2]; J. Aguila, R. [2]; Machorro. [2]

Universidad Autónoma de Baja California, Carretera Transpeninsular Ensenada-Tijuana Numero 3917; Centro de Nanociencias y Nanotecnología-Universidad

Nacional Autónoma de México, Km 107 Carretera Tijuana-Ensenada. Ensenada, Baja California

Currently, an application of optical filters in the industry is the low emissivity (Low-E) filters on

windows, usually based on silver thin layers. This transparent metallic coating allows the visible light

to pass through a window, but blocks longer-wavelength radiation, specifically infrared radiation.

Low-E glass coatings can reflect up to 90 percent of the long-wave thermal energy, allowing much

of the shorter-wave visible light to pass through.

In this work, Low-E optical filters based on multilayers structure have been designed and

synthesized, using copper as an alternative material instead to silver. These coatings consist of thin

copper layers between two layers of aluminum oxide (Al2O3) and titanium oxide (TiO2) on BK7 glass.

The synthesis method used was magnetron sputtering technique. The optical characterization of

each layer was by in situ ellipsometry, plasma spectroscopy and UV-VIS spectrophotometry.

Acknowledgments


(CB-2015-254494, PAPIIT-UNAM IT101017).

References:

1. Chiras, D. D. (2002). The solar house: passive heating and cooling. Chelsea Green Publishing.

2. H. A. MacLeod, Thin-Film Optical Filters, 4 ed., CRC Press Taylor & Francis Group, 2010.

3. S. D. Rezaeia, S. Shannigrahi and S. Ramakrishn, "A review of conventional, advanced, and

smart glazing technologies and materials for improving indoor environment," Solar Energy Materials

& Solar Cell, vol. 159, pp. 26-51, 2017.

4. S. Larouche and L. Martinu, "OpenFilters: open-source software for the design, optimization,

and synthesis of optical filters," Applied Optics, vol. 47, no. 13, pp. C219-C230, 2008.


AMPN - 44


Magnetic Nanoparticles Based on Fe3C@ZnO for Photocatalytic Degradation of Amaranth Dye Used in Textile and Food Industry

E. Canino – Gómez [1, *]; G. Soto – Castañeda [ 1]; A. Ortiz – Atondo [ 1]; M. Landeros [ 1]; L. A. Arce – Saldaña [ 2]; J. Lopez [ 3]; D. dominguez [ 4]; H. Tiznado [ 4]; G. Soto [ 4]

Universidad Autónoma de Baja California (UABC), Facultad de Ingeniería, Arquitectura y Diseño; Centro de Investigación Científica y de Educación Superior de

Ensenada (CICESE);CONACYT – Centro de Nanociencias y Nanotecnología (CNyN); Universidad Nacional Autónoma de México (UNAM), Centro de Nanociencias y

Nanotecnología (CNyN)

Photocatalysis has emerged as an advance and environmental-friendly process for breakdown of

contaminants in wastewater. This work describe the fast synthesis and characterization of magnetic

nanoparticles based on Fe3C@ZnO. The synthesis method was direct from iron (III) chloride

hexahydrate and urea salts placed in a reaction tube and pyrolyzed by a plasma produced under

vacuum conditions using a conventional microwave oven converted into a plasma reactor. Magnetic

nanoparticles powders were coating with 40 nm of ZnO thin film via Atomic Layer Deposition

method at 150°C as photoactive material. The material obtained was characterized via transmission

electron microscopy; X-ray diffraction and X-ray photoelectron spectroscopy. The photocatalytic

degradation of amaranth dye used in textile and food industry was investigated. Catalyst dose of

Fe3C@ZnO was 5 mg in 25 mL solution of colorant. The mixing (nanoparticles plus amaranth dye

solution) was exposure during 120 min under ultraviolet (UV) irradiation conditions in a

photochemical reactor with (16) 14 watt lamps. We found from absorption measurements, that

around of 70 % degradation was achieved within 2 h of the colorant. Finally the catalytic material

was recovery via magnetic separation in order to make catalyst performance and losses testing. We

conclude that the combination of magnetic and photoactive properties makes this material

interesting for several applications through the use of magnetic separation protocols.

Keywords: Magnetic nanoparticles; Photocatalysis; Wastewater treatment; Atomic Layer

Deposition; Magnetic separation.

Acknowledgements

TThis work was partially supported by project UABC-PTC-595 PRODEP-SEP, México and Dirección


PE100318, PE101317, PAPIIT IA 101018, IN 112117, IN 110018, IA 103117 and FORDECYT - CONACYT

272894. The technical assistance of F. Ruíz, E and H. Borbón.


AMPN - 45


Measurement of the thicknesses using Raman spectroscopy of silicon oxides grown on silicon wafers

A. Mora-Lazarini* [1]; G. Alonso-Nuñez [1]

Centro de Nanociencias y Nanotecnología (CNyN), UNAM, 22860, Ensenada B.C., México

The RAMAN spectroscopy for the analysis growths of silicon oxide, specifically the thickness of the

oxide layer, has been useful to support other measurements such as FTIR. [1,2] The use of this oxide

layer is relevant due to its electrical properties [3]. The interest was to see if it was possible to use

this method of spectroscopy to make thickness measurements [4]. Among the multiple uses of

silicon oxide is its compatibility with integrated circuit manufacturing technology, offering different

band gap widths, as well as having a greater control on the creation of thin films that could be used

with nanoparticles in optoelectronic devices. The samples that were analyzed were N-type

crystalline silicon wafers without dopants and an orientation (100) with a resistivity of 100 - 3000

Ω-cm (Sigma Aldrich, 646687) to which a growth of silicon oxide was made by the dry oxygen

method at a temperature higher than 1000 ° C and 8 hrs and atm pressure (open system). The

measurements were made in a RAMAN HORIBA model OLYMPUS BX41 equipment using a 532 nm

laser. Results indicate how the intensity is reduced as the thickness of the oxide increases [3], thus

confirming the utility of the method employed.

Acknowledgement

We would like to thank CONACyT by postdoctoral fellowship, CNyN-UNAM, Ensenada for the

support and equipment in this research and Project 117373. Special thanks to Dr. Esqueda Barrón

Yazmin and Dr. Manuel Herrera for their expert technical assistance.

References

[1] M.L. Green, D. Brasen, K.W. Evans-Lutterodt, L.C. Feldman, K. Krisch, W. Lennand, H-T Tang, L.

Manchanda, M.T. Tang, Appl. Phys Lett. 65 (7), 1994

[2] T.H. Yeh, Thermal Oxidation of silicon, Components Division, International Machines

Corporation, Ponghkkeepsie, New York, Journal of Applied Physics Vol. JJ No. 9, 1962

[3] B.E. Deal, A.S. Grove, Journal of Applied Physics Vol. 36, No. 12, 1965

[4] A. Morales-Acevedo, G. Francisco Pérez Sánchez, Superficies y Vacío 16(2), 16-18, 2003


AMPN - 46


Metal nanoparticles incorporation into low density materials

Becerril-Castro I. B. [1,*]; Castro-Ceseña A. B. [1]; Muñoz-Muñoz F. [3]; Romo-Herrera J. M. [2]

CICESE;CNyN-UNAM;UABC

Detection of molecules in gaseous solutions is of great importance for controlled substances

monitoring, food safety control and detection of highly toxic molecules. As general rule fast and

efficient detection is request it, therefore the highest possible sensitivity is required.

Raman signal is rich in information related with the structure and chemical composition. To

increase the Raman signal intensity, the interaction between the analyte and a metallic surface

where high intensity electric field regions exists is exploited. These regions amplify the Raman signal

intensity and the signal is called SERS (Surface Enhanced Raman Scattering). Moreover, when the

metallic surface used corresponds to surfaces which are from metal nanoparticles (NPs) very close

to each other, the electric field redistribution yields local high intensity regions called hotspots.

Hotspots increase the Raman signal intensity. Then the main challenge is to promote the

interactions between the analyte and metallic NPs surfaces. Therefore, a material which allows an

efficient and high flow of gaseous solution at the surroundings of the NPs is required.

In this work, we proposed the incorporation of metal (Au) nanoparticles into low density

materials as candidates to detect analytes from gaseous solutions. Three morphologies: spheres,

rods and cubes are explored because its different plasmonic response. The proximity with other

nanoparticles in the final material is modified by varying the density of nanoparticles incorporated

into the low density matrix for the generation of hotspots.

Acknowledgements: We would like to thank financial support from DGAPA-PAPIIT IN105719 and

CONACyT Fordecyt 272894. We are very thankful to Jaime Mendoza, Francisco Ruiz, Eloisa Aparicio,

David Dominguez, Jesus A. Diaz, Eduardo Murillo and Israel Gradilla.


AMPN - 47


Modeling of silicon oxide formation in the hysteresis cycle in reactive sputtering by the Co-Sputtering Simulation software and Optical Emission Spectrometry

j. cruz[*,1]; r. sanginés [2]; n. abundiz-cisneros[2]; r. machorro-mejía [1]; s.muhl [3]

CNyN-UNAM; CONACYT-CNyN-UNAM; IIM-UNAM

The biggest problems in the coatings industry is the drop in the deposition rate in reactive

sputtering. By increasing reactive gas flow to obtain the desired compound, a change in the

discharge voltage is usually observed as well as an increase in the system total pressure. This

phenomenon is related to the change in the secondary electron emission and the pumping or

consumption, of the reactive gas in the system. In this work, we present the possible solutions to

the drop of the deposition rate using a Si target and oxygen as reactive gas, taking into account the

chemisorption of the oxygen ions on the racetrack surface.

The Co-Sputtering Simulation Reactive mode software, CO-SS Rm, was developed by the authors to

simulate the distribution of the deposition thickness at the substrate of target material, oxides or

nitrides. The software works by analyzing the sputtering yield as a function of the reactive gas

amount, in addition to providing the angular distribution of compound or metallic species ejected

from the target.

The simulations carried out with CO-SS Rm took into account the various phenomena that occur in

the target in order to explain the thickness decrease of the films as a function of the amount of

reactive gas. The sputtering of the target include the ejection of metal atoms and the formation and

ejection of silicon oxide from the racetrack surface. The simulations were compared with silicon and

silicon oxide thin films thickness measurements by means of an Optical Profilometer, while the

deposit was monitored with Optical Emission Spectroscopy, OES, analyzing the emission lines of

silicon, argon and oxygen.


AMPN - 48


Morphological and structural effects on Carbon Nanotubes subjected to oxidizing media of ozone and plasma.

D. Frausto*[1]; H. A. Borbón-Nuñez [2]; O.A. Romo-Jimenez[3]; J. M. Romo-Herrera [3]; F.F. Castillón [3]; G. Soto [3]; H. Tiznado [3]

Universidad Autónoma de Baja California, Facultad de Ingeniería, Arquitectura y Diseño; CONACyT- Centro de Nanociencias y Nanotecnología. Universidad

Nacional Autónoma de México; Centro de Nanociencias y Nanotecnología. Universidad Nacional Autónoma de México

The selective functionalization of carbon nanotubes (CNTs) surface is key to application in various

fields of science, because the hydrophobic and inert characteristics of synthesized nanotubes at

laboratories. For this purpose, could be used oxidizing agents to create functional groups and

defects on the nanotubes surface. The control of chemical composition of the CNTs surface allows

the application of these as nanostructured sensors of high specificity and sensitivity. Likewise, it

allows the use of the CNTs as sacrificial templates for the development of ceramic material 1D

structures. In the present work, we present a comparative study of the CNTs functionalization,

synthesized by means of spray pyrolysis technique, exposed to oxidizing environments. The CNTs

were exposed to an ozone atmosphere for 40 and 60 minutes, at room temperature. On the other

hand, the CNTs were exposed to a reactive plasma for 5, 10, 20 and 30 minutes. The evolution of

the hydroxyl, carboxyl and carbonyl functional groups on the surface of the CNTs was studied by

infrared spectroscopy. Likewise, the structural properties of the graphitic net of the CNTs was

evaluated by Raman spectroscopy. The morphology of CNTs were studied by SEM and TEM, before

and after been exposed to oxydazing atmospheres.

Acknowledgments

This work was supported by DGAPA–UNAM research projects: PAPIIT IA103117, IA101018,

IN110018, IN112117 and PAPIME PE100318, PE210219 and PE101317 projects, and CONACyT

through the FORDECyT project 272894. The authors would like to thank D. Dominguez, F. Ruiz, J.

Mendoza, J. A. Díaz, I. Gradilla, E. Murillo and E. Aparicio for technical assistance.


AMPN - 49


Nanoporosity in Analcime natural Zeolites from Chiriqui, Panama: Pristine zeolite and after Acid Treatment

Miguel-Angel Hernández[1]; Cecilio Hernández[2]; Jorge Olmos[2]; Martha-Alicia Salgado [3]; Roberto Portillo[3]; Lizeth Ortiz[4]; Liliana Gomez[4]; Miguel-Marcelo Hernández[4]; and Efraín Rubio[5]

Departamento de Investigación en Zeolitas, Universidad Autónoma de Puebla, Puebla 72570, Mexico; Universidad Tecnológica de Panamá, Panama; Facultad de

Ciencias Químicas, Universidad Autónoma de Puebla, Puebla 72570, Mexico; Facultad de Ingeniería Química, Universidad Autónoma de Puebla, Puebla 72570,

Mexico; Centro Universitario de Vinculación y Transferencia de Tecnología, Universidad Autónoma de Puebla, Puebla 72570, Mexico

The present work describes the main results of nanoporosity on natural Analcime zeolite (ANA) both

pristine and chemically treated (ANAH1, ANAH2 and ANAH3). Textural parameters from N2

adsorption isotherms at 77 K were evaluated by the BET, Langmuir, Dubinin-Astakhov (D-A), Barrett-

Joyner-Hallenda (BJH), and Adsorption Differential Curves (ADC) equations. At the same time, the

samples were studied by DRX, SEM and FRX. The nanopore size distribution was calculated through

the DA and ADC methods. First of all, zeolites samples obtained values very close to the reported

dimensions for this type of zeolites. However, the intensity in their distribution of nanopores is more

intense in the ANA zeolite than in the chemically treated ANAH. The results of mesoporosity

evaluated with BJH equation indicate that there is a predominant group of pores in the 3.6 nm zone,

which could be associated with the presence of pores in the form of parallel plates corresponding

to montmorillonite clay. The diffraction pattern of the natural sample indicates that the tuff pristine

ANA exhibits the majority presence of the Analcime zeolite, ANA, in addition to considerable

amounts of montmorillonite, Diopside, and quartz. The quantification of the percentages of the

present phases was done by means of Rietveld Refinement with High Score Plus 3.0e software. On

the other hand, X-ray diffraction patterns of chemically modified analcime zeolites show the

characteristics bands of analcime zeolite after the chemical treatments. Meanwhile, signs of

montmorillonite clay disappear and the characteristic peaks of Diopside prevail with the acid

treatments. The objective of the present work is to characterize the deposits of zeolites from

Chiriqui, Panama with physicochemical techniques and to compare with the proposed experimental

methods the nanoporosity of these zeolites.


AMPN - 51


OXYGEN INFLUENCE ON THE CATODOLUMINESCENCE PROPERTIES OF GAN NANORODS

Aaron M. [1]; Gabriela G. [1]; and Manuel H. [1]

Centro de Nanociencias y Nanotecnología (CNyN-UNAM), Km 107 Carretera Tijuana-Ensenada. Ensenada, Baja California, México

We report a cathodoluminescence (CL) study of oxygen doped GaN micro- and nanorods

synthesized on Ni0.8Cr0.2/ Si (100) substrates by thermal evaporation (TE) method; Oxygen was

incorporated at different concentrations by varying the growth temperature parameter. Three

samples grown at temperatures of 900, 850 and 800 °C revealed oxygen concentrations of 8.7, 10.9

and 12.1 atomic percent. SEM images showed the formation of microstructures with cross-sectional

faces corresponding with the wurtzite (0001) basal plane, and nanorods of about 70 nm in diameter

with triangular nanocrystals decorating its surface. DRX measurements demonstrated a high

crystallinity for the GaN:O samples, with a hexagonal crystalline system corresponding with the

wurtzite-type structure. Raman spectra of the samples revealed a shifting towards low energies for

the A1 (LO) mode induced by basal stacking faults (BSFs) and by oxygen incorporation in the GaN

crystal lattice. CL spectra obtained at room temperature from samples showed an intense emission

centered at 3.39 eV that corresponds to the GaN band edge, as well as three emissions centered at

3.25, 3.1 and 2.1 eV. For these three last emissions, a red-shift was observed as consequence of

decreasing the growth temperature of the GaN samples. The 2.1 eV emission corresponds to the

well-known defect-related GaN yellow emission, possibly related with VN. The UV band centered at

3.25 eV, was identified as a donor-acceptor pair (DAP) recombination, attributed to the presence of

oxygen as impurity, forming a VGa-ON complex point defect. We propose that VGa-ON point-

defects, trapped at dislocations, and other structural defects are responsible of the yellow emission.

We also propose that the emission centered at 3.1 eV is due to the formation of triangular

nanocrystals that decorates the GaN nanorods, in agreement with other reports.


AMPN - 53


Optimizing the nitrogen content in doped carbon nanotubes inks.

José M. Ruiz Marizcal [*1,4]; David Morales G. [2]; Hugo Borbón Núñez [3]; David Domínguez [4]; Hugo Tiznado [4]; Oscar E. Contreras [4]; José M. Romo-Herrera [4]

Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE); Universidad Autónoma de Baja California (FIAD-UABC); CONACyT – Centro de

Nanociencias y Nanotecnología de la UNAM (CNyN-UNAM); Centro de Nanociencias y Nanotecnología de la UNAM (CNyN-UNAM)

The Dye Sensitized Solar Cells (DSSCs) correspond to an attractive method to generate electricity

economically by making use of the solar energy. One of the important components in the DSSCs is

the counter electrode and its catalytic activity, with a great room for improvement. Nowadays, most

of the DSSCs use a Pt film as the counter electrode due to its high catalytic activity. However, the Pt

scarcity and high costs makes necessary to look for efficient alternatives.

Therefore, we propose to substitute the platinum film by a film of nitrogen doped carbon nanotubes

(CNx). The CNx not only present good electrical and mechanical properties, but its nitrogen doped

sites have been found as good catalytic sites. The synthesis of CNx is performed by CVD technique

assisted with spray pyrolysis. We start by exploring the proportion of Nitrogen doping along the

carbon networks of the nanotubes. In order to increase the nitrogen content in the CNx we are

varying the type and amount of chemical precursors with high contents of nitrogen, such as:

Triphenylamine (C18H15N) which has three carbon rings around the Nitrogen; and Iron (III)

Ferrocyanide (Prussian blue) which has six nitrogen atoms around an iron (Fe4[Fe(CN)6]3). Every

reagent is mixed with an organic solvent into a precursors solution before the synthesis begins. A

series of synthesis experiments are performed where the synthesis temperature is being modified.

The obtained samples are analyzed by Scanning Electron Microscopy (SEM), X-ray Photoelectron

Spectroscopy (XPS) and Thermogravimetric Analysis (TGA). Finally, the samples with the more

efficient nitrogen content are being dispersed into CNx inks, by following a hydro-thermic treatment

yielding a water based ink.

Acknowledgements: We thank financial support from DGAPA-PAPIIT IN105719 and CONACyT

Fordecyt 272894. We are very thankful to Jaime Mendoza, Francisco Ruiz, Eloisa Aparicio, Jesus A.

Diaz, Eduardo Murillo and Israel Gradilla.


AMPN - 55


Packing gas particles as hard spheres in a Mordenite nanopore using Monte Carlo Simulation

García-Curiel, E. R. [*,1]; Ungson, Y. [1]; Burtseva, L. [1]; Valdez, B. [1]; Petranovskii, V. [2]

Instituto de Ingeniería, Universidad Autónoma de Baja California, Mexicali, B. C., México ;Centro de Nanociencias y Nanotecnología, Universidad Nacional

Autónoma de México, Ensenada, B. C., México

The study of zeolites, as well as related microporous and mesoporous materials with an ordered

structure of homogeneous pores is one of the most active areas in the field of materials due to

impact on science and technology. Mordenite is a zeolite, which plays a key role in many novel

industrial applications. The reason is that this zeolite belongs to the so-called "big five"- a group of

the most used catalysts in the industry. Therefore, there is a constant interest in a detailed study of

this material.

The filling of the zeolite frameworks by guest particles is usually simulated using the theory and

approaches of the sphere packing in restricted volumes. Ideal gas particles, such as Ar, Rn, Kr, He,

Ne, Xe, can be modeled as hard spheres, if they are based on kinetic diameter. In the simulation

schemes, the Monte Carlo (MC) and Molecular Dynamics (MD) methods are highlighted. The

majority of these methods are developed for the regularly shaped containers, such a cylinder or a

cube. However, they do not represent the zeolite framework correctly, either the dimensions or

shapes of the main channel and interconnection. In the case of the MOR, whose common

representation is based on regular cylinders, an elliptical cylinder resembles its framework more

closely [1].

In this work, an adsorption process of ideal gases was simulated as a sphere packing model in the

MOR main nanopore using the MC method. The nanopore was designed with a 12MRc morphology,

filing an elliptical cylinder with particles of every above-mentioned gases. In the computational

experiment, the adsorbed particles were represented as hard spheres with corresponding kinetic

diameter. The simulation algorithm was developed using two computational schemes; the obtained

structures, as well as the formed occupation volume, were analyzed.

[1] Simoncic, P.; Armbruster, T. Peculiarity and defect structure of the natural and synthetic zeolite

mordenite: A single-crystal X-ray study. Am Mineral, 2004, 89, 421


AMPN - 56


Bi4Ge3O12:Eu and LiGa5O8:Cr self-assembled with gold nanorods and their potential use as a theranostic agents

Carlos Belman-Rodriguez [*1,2]; Prakhar Sengar [2]; GA Hirata [2]; Sergio A. Aguila [2]

Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada; Centro de Nanociencias y Nanotecnología, Universidad

Nacional Autónoma de Mexico

The theranostic agents results of ongoing efforts in bionanomedicine to develop more specific,

therapies for various diseases, and to combine diagnostic and therapeutic capabilities into a single

agent.

The luminescent materials research, has been focused in the study of their physicochemical

properties and their potential applications as diagnostics agents in biological systems.

Gold nanorods (AuR) are also materials that has been tested in biological systems. The unique

plasmonic properties of AuR can be exploited in plasmonic phothermal therapy (PPTT) by coherently

photoexciting their conduction electrons to induce surface plasmon formation, nonradiative

relaxation occurs through electron-phonon and phonon-phonon coupling, generating localized heat

that can be transferred to the surrounding environment, allowing to kill cells in a localized way.

In the present work, two luminescent materials: LiGa5O8:Cr (LGO:Cr) and Bi4Ge3O12:Eu (BGO:Eu)

were synthesized, in order to be used as a potential diagnostics agents. AuR were also synthesized

to be used as a potential therapeutic agent by PPTT. The three materials were synthesized

separately.

Herein we present the synthesis and characterization of LGO:Cr and BGO:Eu self-assembled with

AuR by chemical methods forming: LGO:Cr-AuR and BGO:Eu-AuR. The self-assembled materials

were characterized by SEM, TEM, UV-Vis and tested in biological systems to determined its

biocompatibility and their potential use as a theranostic agents.


AMPN - 57


Laser Induced Periodic Surface Structures over extended areas using ultra-short pulsed lasers

Lamborghini Sotelo [1]; Paulina Segovia Olvera [1]

CICESE

Nano-structuring over extended areas on different materials has always been a complex procedure,

requiring a series of steps and controlled environments to achieve a uniform structure, making it

not only a time-consuming method but also an expensive one.

Laser Induced Periodic Surface Structures (LIPSS), also called ripples, have shown to be a promising

alternative to substitute these methods, offering a fast processing time and the advantage of not

requiring controlled environments to accomplish uniform structures, thus reducing the general cost

of the procedure.

Since their first report on 1965 by Birnbaum, the number of publications per year regarding LIPSS

has been increasing, specially with the development of faster lasers, accessing the femtosecond

pulse regime has opened the doorway to study this process over a wider variety of materials.

LIPSS structures have shown to have promising properties for creating hydrophilic/hydrophobic

surfaces, which can inhibit or enhance the growth of particular cells or bacteria. These structures

can also be tailored to present different optical properties for creating antireflective surfaces or

structural colors and some tribological applications.

Previous work developed by our group has found the optimal parameters to create highly uniform

LIPSS on Ti and Bi, but only on the “punctual” regime. This works aims to find and optimize the

parameters required to process extended areas over short periods of time without sacrificing the

quality of the final structures.


AMPN - 59


Super-resolution imaging on metal thin films

C. Ding 1, J. Wei 1 and Mufei Xiao2

Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China; Centro de Nanociencias y Nanotecnología, Universidad

Nacional Autónoma de México km. 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, CP 22860, México

We herein propose a far-field super-resolution imaging with metal thin films based on the

temperature-dependent electron-phonon collision frequency effect. In the proposed method,

neither fluorescence labeling nor any special properties are required for the samples. The 100nm

lands and 200nm grooves on the Blu-ray disk substrates were clearly resolved and imaged through

a laser scanning microscope of wavelength 405nm ?ire required fur the samples. The spot size was

approximately 0.80 µm, and the imaging resolution of l/8 of the laser spot size was experimentally

obtained. This work can applied to the far-field super-resolution imaging of samples with neither

fluorescence labeling nor any special properties.


AMPN - 60


Raman Spectroscopy analysis and electrical properties of Molybdenum (Sulfur,Selenium) Transition Metal Dichalcogenide multilayer crystals.

A. Fajardo-Peralta [1 ;J. Valenzuela –Benavides [2 ,; W. De la Cruz [2 ; and N. Perea-Lopez [3

Postgraduate Program in Nanosciences, CICESE-UNAM ; Centro de Nanociencias y Nanotecnología UNAM ; Center for 2-Dimensional & Layered Materials in Penn

State University

The recent importance of Transition Metal Dichalcogenides (TMDs), which are semiconductors of

the type MX2, where M is a transition metal atom (such as Mo or W) and X is a chalcogen atom

(such as S, Se or Te), provide a promising alternative to graphene and other two-dimensional

structures like boron nitride for use in nanoelectronic devices. From the TMDs family, MoS2 is the

most studied material, exhibiting a unique combination of atomic-scale thickness, direct bandgap,

strong spin–orbit coupling and favorable electronic and mechanical properties. In this presentation

we report the study of the crystal system (MoS1-xSex)2 with a focus interest on the role of the

chalcogenide ion, i.e., the substitution of sulfur by selenium atoms and monitoring the result of the

synthetized crystals by Raman and photoelectron spectroscopy. The electrical characterization of

the multilayer micro-crystals was performed with a micromanipulator point contacts. The I-V

analysis show Schottky diode behavior. The recent state of art and tendency efforts of this research

is to find new information in this TMDs mixture systems about the nature of physical properties like

carrier mobility, photoconductivity and topological phases, which make them useful for

fundamental studies and for applications in high-end electronics, spintronics, optoelectronics,

energy harvesting, flexible electronics.

Acknowledges

We acknowledge the technical support from I. Gradilla, Enrique Contreras in Raman Spectroscopy

assistance and Dr. Eduardo Murillo. AFP acknowledges a phD grant from CONACyT during this work.

Fruitful discussions with Dr. D. Ruiz-Tijerina and Dr. F. Mireles are also acknowledged.

References

1) Wongbong Cho, et. Al. , “Recent development of two-dimensional transition metal

dichalcogenides and their applications”, Materials Today Volume 20, Issue 3, April 2017, Pages 116-

130.


AMPN - 61


Response of Au concave nanocubes LSPR to different refractive index by modifying the medium

Brandon A. Huerta Plaza [1*]; Josué D. Mota Morales [2]; Víctor Ruiz Cortés [3]; José M. Romo Herrera [1]

Centro de Nanociencias y Nanotecnología, UNAM; Centro de Física Aplicada y Tecnología Avanzada, UNAM; Depto. de Óptica, División de Física Aplicada, CICESE

The optical properties of metallic nanoparticles (NPs) are related to the localized surface plasmon

resonance (LSPR). The LSPR corresponds to the collective coherent oscillation of the free electrons

of the metal on the surface of a nanoparticle, as a response to the alternating electric field of some

incident electromagnetic radiation. For Au, these resonance conditions correspond to wavelengths

in the visible or near-infrared spectrum. Moreover, the LSPR wavelength of metal NPs strongly

depends on the particle size, shape, and refractive index of the medium [1-2].

In this work, the sensitivity of the optical properties of Au concave nanocubes (CNCs) to the variation

of refractive index is evaluated by using a deep eutectic solvent (DES). First, we achieved the

stabilization of the Au CNCs in DES with the addition of the cationic surfactant

Cetyltrimethylammonium chloride (CTAC). Then, the sensitivity of the LSPR peak wavelength to the

change of refractive index was explored by modifying the percentage of water in the DES. The LSPR

peak wavelength and the stability of the NPs in the different media were measured by ultraviolet-

visible spectroscopy and the morphology of the NPs was analyzed by TEM.

The results show the sensitivity of the LSPR wavelength to the change of the refractive index

demonstrating the capacity of the Au CNCs to be used in some applications such as optical

biosensors for the detection of proteins, antibodies or bio -markers [2].

Acknowledgments: We thank to UNAM DGAPA-PAPIIT through IN105719 project as well as

CONACYT through the Fordecyt project 272894. We are also thankful to Israel Gradilla, Francisco

Ruiz, Eloisa Aparicio, Jaime Mendoza, Eduardo Murillo and David Dominguez for technical support.

[1] Alvarez-Puebla R. A. & Liz-Marzán L. M., Small, SERS-based diagnosis and biodetection, 6(5), 604-

610, (2010).

[2] Chen H. etal, Lagmuir, Shape-and Size-Dependent Refractive Index Sensitivity of Gold

Nanoparticles, (31), 5233–5237, (2008).


AMPN - 62


Second Harmonic Generation in Nanostructured Metamaterials.

Ulises R. Meza[1]*; Bernardo S. Mendoza[1];W. L. Mochán[2]

CIO; ICF UNAM

In this work, we present a theoretical study of second harmonic generation (SHG) from structured

metamaterials; particularly, an array of cross-shaped vacuum inclusions within a silver host. We

calculate the nonlinear susceptibility tensor, for a large number of geometrical configurations for

the inclusions. We demonstrate that both the SHG intensity and the resonance peaks are highly

sensitive to even subtle changes in the geometry that break the centrosymmetry of the array of

inclusions. Finally, we present a number of optimal configurations for maximizing SHG output within

the infrared-optical range of energies, determined from this systematic study. These results indicate

that these types of metamaterials are extremely promising for SHG, and warrant further study with

different configurations and combinations of materials.

We present the components of nonlinear susceptibility tensor for six different positions of the

vertical cross-bar; the normal cross is totally centrosymmetric and thus the calculated response is

exactly zero.


AMPN - 63


Silicon quantum dots embedded on ZnO applied in silicon solar cells

H.J. Higuera-Valenzuela*[1]; F. Romo-García[1]; A. Ramos-Carrazco[2]; R. Rosas-Burgos[1]; R. García-Gutierrez[2]; O. E. Contreras[3]; and D. Berman-Mendoza[2]

Departamento de Física, Universidad de Sonora (UNISON), C.P. 83000 Sonora, México; Departamento de Investigación en Física, Universidad de Sonora (UNISON),

C.P. 83000 Sonora, México; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, C.P. 22800, Ensenada, Baja California, México

At the present work, we report the incorporation of silicon quantum dots embedded on zinc oxide

(SiQDs-ZnO) as antireflection coating on solar cells. The improvement of the performance of the

photovoltaic devices is reported. The open circuit voltage (Voc) and the short circuit density (Jsc)

showed increments, in the Voc from 0.562 V to 0.572 V and in the Jsc from 16.74 mA/cm² to 21.07

mA/cm². Also, the dependence of the luminescence response of the SiQDs-ZnO by means of the

silicon concentration is studied. The absorption of the SiQDs-ZnO in the UV radiation and the

emission in the visible region extending from 350 nm to 700 nm was observed. As a conclusion,

these results lead to an increment in power conversion efficiency (PCE) from 4.33% to 5.09% which

represents a general improvement of 17.58% on the PCE on this kind of photovoltaic devices used

in this research.


AMPN - 64


Spectroscopic analysis of TiN thin films deposited by DC and pulsed reactive magnetron sputtering

M. Peralta-Arriola [2,*]; N. Abundiz-Cisneros [1]; R. Sanginés [1]; J. Aguila-Muñoz [1]; J. Cruz [3]; R. Machorro[3]

CONACYT, Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México. Apartado Postal 14, Ensenada, B.C., 22800, México; Centro de

Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana No. 3918, Zona Playitas, C.P. 22860, México ; 3 Centro de

Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México. Apartado Postal 14, Ensenada, B.C., 22800, México.

TiN is a transitional metal compound showing covalent and ionic properties, especially TiN films,

exhibit excellent physical and chemical properties, such as low resistivity, high hardness, thermal

resistivity. Because of these properties, TiN films are extensively applied in many fields.

In this work, we present a study of the growth of titanium nitride thin films (TiN) deposited by DC

and pulsed reactive magnetron sputtering. The emission of the plasma is analyzed in real time by

optical emission spectroscopy (OES) and TiN films were measured by in-situ ellipsometric-

spectroscopy to obtain the optimal deposition parameters to make a comparison between deposits

made by DC and DC pulsed. . Finally, this work focuses on the correlations between the plasma

species and the properties and structure of the thin film.

Acknowledgments


(CB-2015-254494, PAPIIT-UNAM IT101017). J. Cruz acknowledges his postdoctoral fellowship from

UNAM. M. Peralta-Arriola acknowledges their scholarship from CONACyT

References

1. Hernandez Utrera, O., Abundiz-Cisneros, N., Sanginés, R., Diliegros-Godines, C. J., y

Machorro, R. (2018a). Cleaning level of the target before deposition by reactive direct current

magnetron sputtering. Thin Solid Films, 646, 98–104. https://doi.org/10.1016/j.tsf.2017.11.035

2. Sanginés et al. “Plasma emission spectroscopy and its relation to the refractive index of

silicon nitride thin films deposited by reactive magnetron sputtering”, Applied Physics, 51(2), 2018.


AMPN - 65


Structural Characterization of Multiferroic Pb(Fe0.5Nb0.5)O3/BiFeO3/SrRuO3 Heterostructure

Diana E. Vázquez Valerdi [*,1]; Subhash Sharma [1,2]; Jesús Siqueiros Beltrones [1]; Oscar Raymond Herrera [1];

Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 Carretera Tijuana-Ensenada. Apartado Postal 14, C. P. 22800,

Ensenada, B. C. México; Investigador de Cátedras CONACYT adscrito al Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km.

107 Carretera Tijuana-Ensenada. Apartado Postal 14, C. P. 22800, Ensenada, B. C. México.

Actually, multiferroic materials are of great academic and technological interest for their potential

applications in a new generation of devices where electrical, magnetic and elastic order coexist. In

this work, we report the structural characterization of the multiferroic and multi-magnetic

Pb(Fe0.5Nb0.5)O3/BiFeO3/SrRuO3 heterostructure deposited on Si(100) substrate by RF-

sputtering. The crystalline structure characterization of the heterostructure was evaluated by X-ray

diffraction (XRD) technique; whereas, the layers thickness, morphology, crystallinity, and chemical

composition analyses were performed from cross-sectional regions by Transmission Electron

Microscopy (TEM) technique. The obtained thin films are highly textured. A vertically [110] oriented

grainy structure is observed. The Pb(Fe0.5Nb0.5)O3 and BiFeO3 films exhibits very high density with

columnar growth. The thickness obtained was 160 nm for the Pb(Fe0.5Nb0.5)O3 film, 140 nm for

the BiFeO3 film, and 710 nm for the SRO film, which are close to those estimated from the deposit

processes.

Acknowledgments

This work was partially supported by PAPIIT-DGAPA-UNAM Grants IN107918 and IN105317. The

authors also thank to E. Aparicio, I. Gradilla, F. Ruiz, P. Casillas for their technical assistance.


AMPN - 66


Synthesis and characterization of multiferroic BiFeO3 thin films by pulsed laser deposition

Mariela Villarreal [*,1]; Ma. de la Paz Cruz [1]; Gabriel Rojas [2]

Departamento de Materiales Avanzados, Centro de Nanociencias y Nanotecnología-Universidad Nacional Autónoma de México; Centro de Investigación en

Materiales Avanzados

Bismuth ferrite (BiFeO3) is a perovskite material with attractive properties in the field of the

multiferroics [1]. Due to its spontaneous polarization and inversion symmetry breaking, it also

displays the so called anomalous ferroelectric photovoltaic effect that leads to applications in

photovoltaic devices [2] For these devices to be possible, more studies about the mentioned effect

in high-quality BiFeO3 thin films, as those obtained by pulsed laser deposition (PLD).

Thus, the present work consisted in finding the optimal condition for deposition of BiFeO3 on

substrates of Pt(150 nm)/ TiO2(50 nm)/ SiO2/Si(100) by PLD. Temperature (400, 450, 500, 550 and

600 ° C) and pressure of O2 (0, 10, 15, 20, 25, 30 mTorr) were varied. The samples were analyzed by

XRD and, it was found that at 550 ° C with a partial pressure of 10 mTorr the BiFeO3 phase (R3c) was

obtained. Consecutively, we proceeded modifying the fluence of the laser in 0.6, 0.71 and 1 J/cm2.

Those thin films were characterized by SEM in order to analyze their morphology. Greater

uniformity was observed in the film deposited at 0.71 J/cm2. This sample was characterized by AFM

/ PFM. From the former characterization it was known that the deposit rate corresponded to 1 nm/s

and it showed a rugosity of 4.381 nm. The latter proved the existence of ferroelectric domains

which were commuted to negative and positive polarizations. Also, its piezoelectric response was

observed obtaining the amplitude and phase curves against voltage.

Acknowledgments

Thanks are due to E. Aparicio, P. Casillas, I. Gradilla and E. Murillo for their technical assistance. This

work has been partially supported by PAPIIT-UNAM proj. IN109016.

References

1. Rojac, T. et al. J. Am. Ceram. Soc. DOI: 10.1111/jace.12982 1–19 (2014)

2. Ding, J. et al. Sci China-Phys Mech Astron, Vol. 57 No. 11: 1–6 (2014)


AMPN - 70


Thin films of CH3NH3PbI3 grown by spin-coating: optimization of deposit conditions and study of degradation

Saviñon-de los Santos, J.[*,1]; Rojas-George, G.[2]; Meraz-Dávila, S.[1,3]; Cruz-Jáuregui, M. P.[1]

Centro de Nanociencias y Nanotecnología, UNAM (CNyN-UNAM). Ensenada, BC, México; Centro de Investigaciones en Materiales Avanzados (CIMAV). Chihuahua,

Chih., México; Centro de Investigación Científica y Estudios Superiores de Ensenada (CICESE). Ensenada, BC, México

Current commercial solar cells are still inefficient and expensive; therefore, the need to have more

efficient and profitable systems. One of the alternatives is using photovoltaic absorbers with a

hybrid pervoskite base. These cells promise a greater efficiency (more than 20%), with the

disadvantage of its short useful life due to the rapid degradation of the absorber under

environmental conditions. In this work, we study the variables that influence the microstructure and

degradation of the hybrid perovskite CH3NH3PbI3 (MAPI), as well as the optimization of the electron

transport layer to improve its adhesiveness and crystallinity, by means of the spin-coating

technique. For this, starting from transparent conductive oxide substrates (FTO|glass), by means of

the sol-gel method using titanium isopropoxide as a precursor deposited by spin-coating and a

subsequent thermal treatment to obtain a TiO2 anatase phase film. Next, the MAPI precursor was

obtained by two methods: (i) the ultrasound method and (ii) direct dissolution of precursors. The

ultrasound method consists of obtain the powder of CH3NH3PbI3 by grinding the powder

precursors and use an ultrasonic bath in CH2Cl2 for 4 h, which allows to obtain a stable powder at

ambient conditions for more than 4 months. After that, precursor liquids for spin-coating using

dimethylformamide (DMF) and/or dimethylsulfoxide (DMSO) at different concentrations, was

prepared. In the direct dissolution method, it is prepared by dispersing PbCl2 and CH3NH3I directly

in DMF and allowing it to stir for 18 h. All perovskite liquid precursors were deposited under the

same conditions. A comparison was made of thickness, roughness, microstructure and crystallinity,

as well as the monitoring of the degradation of the phase CH3NH3PbI3 in its precursors and other

compounds. This work was funding in part by UNAM, proj. PAPIIT- IN109016.

Thanks are due to P. Casillas, N. Abúndiz, S. Meraz and I. Gradilla for their technical help.


AMPN - 71


TiO2 porous pellets synthesize by sol-gel and rapid liquid phase sintering for bone cell implantation

Duilio Valdespino[1 *); Gabriel Rojas[2]; Ma. de la Paz Cruz-Jáuregui[3

Posgrado de Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Tijuana-Ensenada No. 3918, Pedregal

Playitas, Ensenada, B.C., México, C.P. 22860; Cátedratico CONACyT, Centro de Investigación en Materiales Avanzados (CIMAV), S. C., Miguel de Cervantes, Complejo

Industrial Chihuahua, Chihuahua, Chih., México, C.P. 31136; Departamento de Materiales Avanzados, Centro de Nanociencias y Nanotecnología (CNyN),

Universidad Nacional Autónoma de México (UNAM), Km. 107 carretera Tijuana-Ensenada, Ensenada, B.C., México, C.P. 22860.

TiO2 porous pellets coated with calcium phosphate and hydroxyapatite were prepared and studied

to be used as structural supports for cellular bone implantation.

As a first step, powder of TiO was synthesized, at 400 oC for 1 h, by a new simplified process of the

sol-gel technique. The powder was used to formed pellets, with pressures of 832.5 and 624.7 MPa,

that were sintered by the Rapid Liquid Phase Sintering (RLPS) method, at different temperatures

(900, 1000 and 1100 oC) and times (2, 5, 7 and 10 min). Pellets showed a pure rutile phase. The

highest density, of 2.78 g/cm3, was obtained in the sample sintered at 1100oC/2 min.

In another hand, the porous TiO2 pellets were prepared by adding 3350 and 8000 polyethylene

glycol (PEG) to the TiO2 powder, at a PEG/powder weight ratio of 1:4, using 624.7 MPa to pressed

the pellets that were annealed at 450 oC/2 min. The obtained porous sizes were 38.51 ±27.51 m

and 48.98 ±32.34 m when PEG3350 and PEG8000 were respectively used. An additional

sinterization at 1100oC/2 min, produced pellets with pore sizes of 76.82 ±34.23 m and 173.04

±68.03 m for PEG3350 and PEG8000, respectively. Interconnectivity of pores was achieved in all

samples. The highest elastic module, of 12.03 ±0.04 MPa, was obtained in the sample made with

PEG8000 and sintered at 1100oC/2.

With an hydroxyapatite target, prepared sol-gel, films of 7 and 45 nm were deposited by the

sputtering technique, on all samples: with and without pores. The presence of hydroxyapatite on

pellets, was confirmed by XPS, which showed also the appearance of calcium phosphate.

Cell implantation was conducted in all samples (with and without porous, with and without the

coating), by the protocol of cells MC3T3-E1. The highest proliferation, 3.5 times higher than the

control at 72 h, was achieved in the sample prepared with PEG3350, sintered at 1100oC/2 with no

hydroxyapatite-calcium phosphate coating.

This work was funding in part by UNAM, proj. PAPIIT- IN109016.


AMPN - 72


Wave packet dynamics of Kekulé-Y textured graphene

Carrillo-Bastos R. [1]; Iglesias P. [1]; Santacruz A. [*,1]

UABC

The dynamics of a Gaussian wave packet in monolayer graphene with Kekulé-Y distortion is studied

numerically. We calculate the discrete time evolution operator of the low-energy 4-band Dirac

Hamiltonian and develop an accurate and stable method for calculating the time displacement of

the four-component wave function. We show that Kekulé-Y distortion with a strong coupling

constant manifests various unexpected phenomena, including the appearance of precursory wave

packets and the spatial asymmetries that arise thereafter. We speculate on the possible links

between these phenomena and previous observations done by Gamayun et. al. (2018) and Gutiérrez

et. al. (2016).


AMPN - 74


Bi@C and vanadium oxide nanoparticle synthesis by laser ablation of solids in liquids for biological applications and technological applications.

Angela M[*]. Yasmin E. Santiago C

UNAM:CICESE

Bismuth has been frequently used in biomedical aplications as a medium for the treatment of illness

and specific health problems. In its nanoparticle (NPs) form, the properties of bismuth can be used

for tumor treatment or to treat gastrointestinal illness. Several bismuth compounds or bismuth

nanoparticles in combination with electromagnetic radiation have been used for such a purpose.

On the other hand, Vanadium oxide shows optical, electrical and structural properties which are of

high interest for electronics and optics. For instance, different vanadium oxide phases present

characteric coloration. Also, this kind of materials show a sharp conductivity change when

temperature changes; this effect occurs at -113 oC for V2O3 and at 67 oC for VO2. In both cases the

oxide starts as an insulator at low temperatures but then it turns to a conductor beheviour. The

changes in temperature also affect the crystalline structure, as an example we can quote VO2. This

oxide has a monoclinical structure (semiconductor) which then switches to the rutilo phase with a

tetragonal (metal) structure. The main optical feature for these oxides is the characteristic color:

yellow for V2O5, blue for VO2, green for V2O3 and violet for VO. Recent applications for these

vanadium oxides are mainly in the smart window coatings and catalysis technologies.

The laser ablation of solids in liquids (LASL) technique is nowadays a commonly used one for the

synthesis of nanoparticles. Nanoparticles of a wide variety of materials can be synthesized using

LASL, including metals and metallic oxides. The combination of the laser parameters such as the per

pulse fluence, the synthesis time and the nature of the liquid solution are critical for the nanoparticle

formation.


AMPN - 75


CALIBRATION CURVES FOR ATOMIC LAYER DEPOSITION

B. Sánchez[1*];M. Franco[1];X. Ma[2];J. Jurado[3];J. López[4];D. Domínguez[4];H. Tiznado [4]

Universidad Autónoma de Baja California (UABC) Campus Ensenada, Km. 106 Carretera Tijuana-Ensenada, 22800, Ensenada, Baja California, México;Centro de

Bachillerato Tecnológico Industrial y de Servicio No. 41 (CBTIS No. 41), Carr. Transpeninsular, Ex-Ejido Chapultepec, 22875 Ensenada, Baja California, México;Centro

de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California,

México;Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14 C.P. 22800, Ensenada, Baja California, México

Atomic Layer Deposition (ALD) has become in one of the most important techniques to synthesize

thin films, the growth of a thin film is made by cyclical reactions. The most important advantages

of ALD are the precise thickness control, uniformity, conformity, and low deposit temperatures. The

calibration curves helps to find ideal deposition parameters for specific precursor. In this work we

made calibration curves for different precursors: Trimethylaluminum (TMA),

Tris(methylcyclopentadienyl)yttrium ((MeCp3)3Y), Tetrakis(ethylmethylamino)zirconium(IV)

(TMAZr), Tetrakis(dimethylamino)titanium(IV) (TDMAT), each of them with differents oxidizings

agents : water (H2O) and ozone (O3).

The calibration curves were obtained to acquire the deposit parameters of different oxides: Al2O3,

TiO2, ZrO2 and Y2O3, this results allows obtain the dose and purge ideal times, thereby optimizing

the amounts of precursor used for the depositions.

Acknowledgments



like to thank Alejandro Tiznado and Enrique Medina for technical assistance.


AMPN - 76


FABRICATION OF ALD SYSTEM FOR SYNTHESIS OF TiO2 THIN FILMS

M. Franco[1*]; B. Sánchez[1]; X. Ma[2]; J. Jurado[3]; J. López[4]; D. Domínguez[4]; H. Tiznado[4]

Universidad Autónoma de Baja California (UABC) Campus Ensenada, Km. 106 Carretera Tijuana-Ensenada, 22800, Ensenada, Baja California, México; Centro de

Bachillerato Tecnológico Industrial y de Servicio No. 41 (CBTIS No. 41), Carr. Transpeninsular, Ex-Ejido Chapultepec, 22875 Ensenada, Baja California, México; Centro

de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California, México;

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14 C.P. 22800, Ensenada, Baja California, México

Atomic Layer Deposition (ALD) is an important technique for the synthesis of thin films. In this

project ALD system was fabricated using different types of tubing, valves, reactors, etc. Additionally

the system design allows synthesize thin films in substrates with irregular geometry. TiO2 thin films

was synthetized using Tetrakis(dimethylamino)titanium(IV) (TDMAT) as Ti precursor and water

(H2O) as oxidant agent finally Si (110) was used of substrate. The thin films thickness were measured

by UV-Vis spectroscopy and chemical composition was obtained by X ray photoelectron

spectroscopy (XPS). Finally the ideal dose and purge times of TDMAT was obtained by calibration

curves.

Acknowledgments





AMPN - 77


Functionalization of erionite and chabazite zeolites surfaces to CO2 and CH4 capture

Karla-Fabiola Quiroz [1]*; Miguel-Ángel Hernández [2]; Carlos Felipe [3]

Doctorado en Nanociencias y Micro-Nanotecnologías, UPIBI-IPN, Instituto Politécnico Nacional; Departamento de Investigación en Zeolitas, ICUAP-BUAP,

Benemérita Universidad Autónoma de Puebla; Departamento de Biociencias e Ingeniería, CIIEMAD-IPN, Instituto Politécnico Nacional

The present work is based on the capture of greenhouse gasses through the use of natural zeolites,

these materials are nanoporous crystalline aluminosilicates high content of exchangeable cations,

these properties interfere directly in the adsorption capacity of low weight molecular gases, under

these conditions, the cations allow the entry of gas molecules to be trapped in their cavities. Zeolites

type Erionite and Chabazite are naturally found in large amounts in Mexico, the proposal for this

project was to functionalize their surface through ion exchange treatments followed by their

characterization and finally the evaluation of CH4 and CO2 adsorption capacity.

The X-ray diffraction patterns were analyzed by Rietveld refinement of the natural chabazite and

erionite, which allowed to know the quantitative percentages of crystalline phases. In the case of

natural chabazite were found 66.2% of Chabazite-Ca, 33.8% of clinoptilolite and minor amounts of

quartz. About erionite sample, the main percentage obtained corresponds to erionite crystalline

phase with 75.1%, followed by chabazite as a secondary phase with 24.1%, and finally quartz <1%.

The HRSEM micrographs showed the characteristic morphology of the chabazites in a rhombohedral

shape. While erionite crystalline structure can be essentially described as elongated prisms in the

form of thin needles. According to the obtained results in the CO2 capture, erionite-type zeolites

exchanged with Na+ showed the highest adsorption capacity over exchanged chabazite zeolites.

The displacement of Na+ cation at the entrance of the 8MR allows the access of CO2 molecules with

sufficient energy when there is an increase in temperature. This phenomenon has been called

“Trapdoor effect”. Therefore, the use of functionalized natural zeolitic materials such as erionite-Na

can be a viable option in the treatment of polluting gaseous effluents.


AMPN - 80


Luminescent properties of Ga2O3:RE3+ nanomaterial

Nayeli Reyes Moreno [1]; Claudia Alcira Espinoza González [*2,3]; Gustavo A. Hirata Flores [3]

Autonomous University of Baja California; Center for Scientific Research and Higher Education at Ensenada; National Autonomous University of Mexico

In this report, the nanomaterial Ga2O3:RE3+ (RE3+= Eu3+, Tb3+, Tm3+) was synthesized by the sol-

gel method. The nanopowders were post-anneled at 1100 °C for 3h in order to obtain

ananocrystalline phosphor with tunable photoluminescence(PL) properties. The X-Ray Diffraction

(XRD) characterization process yielded the monoclinic phase in agreement with the JCPDS No. 41-

1103 database reports. Nanocrystal morphology was analyzed with Transmission Electron

Microscopy (TEM). A detailed analysis was made on cathodoluminiscence (CL). This nanomaterial

has potential application in nanoelectronics (e.g. LEDs) and nanomedicine (e.g. bioimaging).


AMPN - 81


MANUFACTURING OF ALD SYSTEM FOR THE SYNTHESIS OF ZnO THIN FILMS

X. Ma (1,*) M. Franco (2) B. Sanchez (2) J. Jurado (3) D. Domínguez (4) J. López (4) H. Borbón (4) H. Tiznado (4)

Centro de Bachillerato Tecnológico Industrial y de Servicio No. 41, Carr. Transpeninsular, Ex-Ejido Chapultepec, 22875 Ensenada, Baja California, México;

Universidad Autónoma de Baja California, Km. 103 Carretera Tijuana – Ensenada, Baja California C. P. 22860; Centro de Investigación Científica y de Educación

Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California, México; Centro de Nanociencias y Nanotecnología,

Universidad Nacional Autónoma de México, Apdo. Postal 14 C.P. 22800, Ensenada, Baja California, México.

Nowadays the thin layers are highlighting in different applications of the industry, some of them are

electronic, medical, optics, biological, etc. Atomic layer deposition (ALD) technique, is one of the

most promising technique for the production of thin layers. In this project, we built a system to

synthesize thin layers of ZnO by ALD, the system design allows synthesizing thin layers using

substrate with smooth, porous or powder structure. Silicon (Si) type P (100) was used as a substrate,

Diethylzinc as a precursor of Zn, and water (H2O) as an oxidizing agent. The thin layer thickness were

measured by UV-Vis spectroscopy and the chemical composition were obtained through "X-ray

photoelectron spectroscopy” (XPS) technique, to obtaining characteristic peaks of ZnO.

Acknowledgments





AMPN - 83


Effect of La3+/Sr2+ ordering on the magnetic properties of La2/3Sr1/3MnO3 by first principles calculations

H´Linh H´Mŏk [*,1,2]; Espiridión Martínez Aguilar [1,2]; Jordi Ribas Ariño [3]; Jesús María Siqueiros Beltrones [2]; José Luis Sánchez Llamazares [4]; and Oscar Raymond Herrera [2]


Ensenada 22860, Baja California, México; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, Ensenada 22860,

Baja California, México; Departament de Ciència de Materials i Química Física and IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain;

Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José 2055, Col. Lomas 4ª sección, CP 78216, San Luis Potosí, S.L.P., Mexico.

The La2/3Sr1/3MnO3 (LSMO) material is a promising candidate for Spintronics as a source of spin-

polarized electron current. To date, many theoretical works have been focused on describing the

physical properties of La1-xSrxMnO3 with cubic and/or tetragonal perovskite structure. However, a

detailed discussion on the effect of the Sr distribution on the magnetic properties of LSMO is still

missing in the Literature. In this work, using DFT+U formalism, we investigate the effect of the order-

disorder in the A-site occupation by La3+ and Sr2+ on the stability of the ferromagnetic order in

LSMO bulk with 𝑅3𝑐 symmetry. For this purpose, we employ structural models corresponding to

rhombohedral R3c symmetry consisting of 120 atom supercells constructed according to the precise

stoichiometry of the compound. Two configurations, describing randomized and ordered

occupation of the La3+ and Sr2+ ions, are evaluated. The electronic structure of these configurations

has been studied by means of an analysis of their density of states, band structure, electron density

and electron localization function. We have demonstrated that the ferromagnetic arrangement of

the LSMO with La3+ and Sr2+ ions randomly distributed is more stable than that with an ordered A-

site occupation. We find that with the random configuration, is not possible to distinguish between

Mn3+ and Mn4+ ions, thus favoring the double-exchange mechanism, which in turn is enhanced by

the high degree of covalence in the Mn-O bonds near the Fermi level between the spin-up Mn-eg

orbitals with the O-p orbitals.

Acknowledgments: This work was partially supported by PAPIIT-DGAPA-UNAM Grants IN107918

and IN105317. The authors thank the computer support thorough Projects LANCAD-UNAM-DGTIC-

351. The authors thank A. G. Rodriguez Guerrero and P. Casillas for their technical assistance. H´Linh

H´Mŏk and E. Martínez-Aguilar thank CoNaCyt for Scholarship Grant 290784 and 290934,

respectively.


AMPN - 84


On the Structure and Electronic Properties of LTA-Zeolite

Joel Antúnez-García*[1]; Rosario I. Yocupicio-Gaxiola [1]; Fabian N. Murrieta-Rico [1]; Donald H. Galván [1]; Aldo Arteaga Morales[1]; Vitalii Petranovskii [1]; Sergio Fuentes [1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada Baja California, C. P. 22860, México

Using first-principles calculations, the structure and electronic properties of LTA-zeolite were

studied. Our studies show that in order to describe properly the structure observed experimentally

(with a Si/Al=1 ratio), it is required a triclinic unit cell instead the cubic one described in the

literature. The structure presented in the proposed unit cell shows that the primary cage

corresponds to the formed by double four-member rings (D4R) and when these are connected

through oxygen bridges; give rise to β-cage (sodalite cage) as secondary and subsequently to the α-

cage. From theoretical results, it was found that a slight anisotropy in Al distribution is more

favorable energetically, which represents a violation of the Löweinstein’s rule. On the other hand,

our results reveals that the zeolite presents a magnetic behavior when a Fe3+ cation is

isomorphically exchanged by an Al3+ cation.


AMPN - 85


STUDYING THE PROPERTIES OF POROUS MATERIALS BY HARD SPHERES AND MOLECULAR DYNAMICS APPROACH: PARTICLE COLLISIONS IN IRREGULAR CHANNELS

Yamel Ungson [*,1]; Edwin R. Garcia-Curiel [1]; Larysa Burtseva [1]; Benjamin Valdez Salas [1]; Vitalii Petranovskii [2]

Instituto de Ingeniería, Universidad Autónoma de Baja California, México; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México,

México

In the literature, the importance of collisions in molecular simulations has been highlighted,

especially in method of Molecular Dynamics (MD). The modeling of the collisions is necessary to

determine and predict the behavior of the particles in porous materials, such as zeolites. Simulations

make possible to understand the nature of these systems; the most of simulations consider the

work-space as infinite or as container in a regular shape, such as a cylinder or a cube. However, in

real systems the geometry of the container is irregular, i.e. in porous materials the channels are

usually constricted. The objective of this work is present the models of the particle collisions in such

irregular-shaped spaces. The proposed equations for modeling particle collisions are restricted to

channels with a round cross section and their walls present shapes as a cone or a sphere, whether

complete or truncated, tilted cylinders, round tubes with sinusoidal or wavy form, as well as their

extensions and combinations [1]. A MD simulation of hard-sphere packing in a wave channel was

executed in software MATLAB ®. This simulation represents a packing of the noble gas Argon (Ar)

atoms in Erionite; this zeolite usually occurs as thin fibers forming a non-regular channel similar to

a truncated peanut-shape. Some static properties of the system were computed: the characteristic

pore of the zeolite was occupied with an amount of 13 atoms, considered as perfect hard spheres,

obtaining a porosity of 73.3% and a packing factor of 26.7%. In a future work, particle collisions in

irregular-shape containers will be modeled as soft-spheres, since the real behavior of many bodies

presents inelastic collisions when hitting each other.

[1] Ungson, Y.; Burtseva, L.; Garcia-Curiel, E.R.; Valdez Salas, B.; Flores-Rios, B.L.; Werner, F.;

Petranovskii, V. Filling of Irregular Channels with Round Cross-Section: Modeling Aspects to Study

the Properties of Porous Materials. Materials 2018, 11, 1901.


AMPN - 87


Nanometric analysis of an axon including a carbon nanotube

Ana Mizrahim Matrecitos Burruel [1] ; Ricardo López Esparza[1]

Posgrado en Nanotecnología, Departamento de Física, Universidad de Sonora

In diseases such as epilepsy, carbon nanotubes can inhibit the over excited state that occurs in the

seizures due to the desynchronization of the signal passing through the connexins. Some of the

mathematical models describe this desynchronization without the presence of elements such as

carbon nanotubes, which can serve as a liaison between two neurons. In this work, we study the

propagation of nerve signals in the axon when a carbon nanotube is present, as a problem of first

principles with possible extension to the health problem mentioned before. Starting from the cable

equation we add an electronic element according to the physical properties of carbon nanotube,

and propose an analytical solution.


AMPN - 89


Structure and dynamics of organic molecules intercalated in H2La3Ti3O10 layered perovskite photocatalyst

Lushpinskaya I. P.[1]; Shelyapina M.G. [*,1]; Kurnosenko S.A. [1]; Silyukov O.I. [1]; Zvereva I.A. [1]

Saint Petersburg State University, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia

Organic-inorganic layered perovskites due to their remarkable properties are considered as

promising photocatalytic materials. For the successful development of these composite hybrid

nanomaterials, knowledge on the structure and dynamics of both structural parts are highly

required. Here, we report the results of our complimentary study by X-ray diffraction, thermal

analysis and nuclear magnetic resonance (NMR) technique of the structure, stability and dynamics

of H2La2Ti3O10 Ruddlesden-Popper layered perovskites with organic molecules (methanol,

methylamine, n-butylamine, ethanolamine) introduced into the interlayer space. High-resolution

13C and 1H NMR spectroscopy has been used to study the mobility of protons and organic molecules

in the hybrid compounds. For 1H nuclei the chemical shifts have been attributed to the protons

belonging to the intercalated organic molecules, water molecules and lattice protons. The 13C NMR

spectra of intercalated molecules have been registered depending on the duration of the cross-

polarization pulse (CP-MAS experiment). As part of the static NMR experiment, the components of

the magnetic screening tensor on 13C of the intercalated organic molecules have been measured.

In combination with quantum chemical calculations, the results of these experiments help to find

the position and conformation of the intercalated molecules in these hybrid compounds. To

determine the motional parameters of the intercalated molecules the spin-lattice relaxation times

of 13C and 1H nuclei have been measured over a wide temperature range.

The research has been done at the Research Park of Saint Petersburg State University: Centre of

Thermal Analysis and Calorimetry, Centre for X-ray diffraction study and Centre for Magnetic

Resonance. The work was supported by the Russian Foundation for Basic Research (Grant 18-03-

00915).


AMPN - 90


Study of UNCD thin films for cover ion-litium batteries

Michelle Judith Salgado Meza[1] *; Rafael García [1]

UNISON

The accelerated development of energy storage technology for laptops, cell phones or other mobile

devices has raised the need to produce longer-lived batteries later, so as to provide an increase of

one order of magnitude, if possible, in the life cycle of these devices, after charging the battery, in

order to take advantage simultaneously of the efficiency they offer, as well as the possibility of

perpetuating it during its use, An additional effect that is very important is that the batteries are

much more safe to avoid accidents caused by uncontrolled heating like the one that occurred with

the battery of a cell phone in 2016, which resulted in two trillion dollars of loss for the world class

company in Korea.

There are several technologies in the electrochemical cells that constitute the batteries, in the

present proposal we will focus on those secondary cells, which include the lithium-ion batteries (Li-

ion batteries (LIB)) that are the most important commercially. in the present time. It is proposed to

coat the electrodes with UNCD to increase the useful life of the batteries.


BIO - 1


Effect of antimicrobial nanocomposites on Vibrio cholerae biofilm formation

Meza-Villezcas, A. [*, 1, 2]; Gallego-Hernández, A. L. [3,4]; F. H.Yildiz [4]; O. E. Jaime-Acuña [2]; O. Raymond-Herrera [2]; A. Huerta-Saquero [2].

Centro de Investigación Científica y de Educación Superior de Ensenada; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México;

Departamento de Investigación en Física, Universidad de Sonora; Microbiology and Environmental Toxicology Department, University of California Santa Cruz

Cholera is an acute diarrheal infection with a high frequency in developing countries caused by

ingestion of food or water contaminated with Vibrio cholera, an important human pathogenic

bacteria. V. cholerae has the capacity to switch between planktonic and biofilm lifestyles. Biofilms

are surface-attached microbial communities, composed of microorganisms and extracellular matrix,

which induces a hyper-infectious phenotype and increases bacterial antibiotic resistance. Due to the

enhanced antibiotic resistance observed by bacterial pathogens, antimicrobial nanomaterials have

been used to combat infections by ceasing bacterial growth and avoiding biofilms formation. In this

study, the effect of the nanocomposites zeolite-embedded silver (Ag), copper (Cu), or zinc (Zn)

nanoparticles (NPs) was assayed in V. cholerae planktonic cells, and in two biofilm states: the pellicle

biofilm (PB), formed between air-liquid interphase and, the surface-attached biofilm (SB), formed

at solid-liquid interfaces. Each nanocomposite type had a distinctive antimicrobial effect affecting

each V. cholerae lifestyles differently. The ZEO-AgNPs nanocomposite inhibited PB formation at 4

μg/ml, and prevented SB formation and eliminated planktonic cells at 8 μg/ml. In contrast, the

nanocomposites ZEO-CuNPs and ZEO-ZnNPs affected V. cholerae viability but did not completely

eradicate bacterial growth. At transcriptional level, depending on the nanoparticles and biofilm

type, nanocomposites modified the relative expression of the vpsL, rbmA, and bap1, genes involved

in biofilm formation. Furthermore, the relative abundance of the outer membrane proteins OmpT,

OmpU, OmpA, and OmpW also differs among treatments in PB and SB. This work provides a basis

for further study of the nanomaterials effect at structural, genetic and proteomic levels to figure out

the response mechanisms of V. cholerae against metallic nanoparticles. **Scientific names should

be written in italics**


BIO - 2


Silver nanoparticles for the cytotoxic and modulatory activity effect of the multidrug-resistant associated P-glycoprotein in breast cancer cell lines.

María Dolores Rivera-Guzmán [1,*], Karla Oyuky Juarez-Moreno [2,3].

1. CICESE, 2. CNyN-UNAM, 3. CONACYT-CNyN.

Cancer is one of the leading causes of death worldwide. It is known that nanotechnology provides

excellent tools to fight against cancer. Due to its well-known properties as antibacterial, antiviral

and anti-inflammation agents, one of the most used nanomaterials in biomedicine are silver

nanoparticles (AgNPs). Multidrug resistance (MDR) is a major obstacle to successful cancer

chemotherapy. One important mechanism of MDR involves the multidrug transporter, P-

glycoprotein (Pgp), which confers upon cancer cells the ability to resist lethal doses of certain

cytotoxic drugs by pumping the drugs out of the cells and thus reducing their cytotoxicity. Taking

into account the advantages of AgNPs, in this work we evaluated the antiproliferative effect of

different concentrations of commercially AgNPs in breast cancer cells by a colorimetric assay.

Apoptosis and necrosis cell death was also evaluated by flow cytometry. Moreover, the cytotoxic

effect of AgNPs in breast cancer cells was determined with a migration assay. To evaluate the P-gp

inhibitory potential of AgNPs in breast cancer cells, flow cytometry technique was assessed to

determine the pump efflux activity. Rhodamine 123 was used as a target of P-gp pump, the increase

of fluorescence dye was measured in breast cancer cell lines treated with and with out AgNPs. Our

results showed that there is a concentration dependent cytotoxic effect of AgNPs in breast cancer

cell lines. The driven cell death modality is evoked by apoptosis. The reduction of the activity of P-

gp pump was observed by the increase of Rhodamine inside the cells treated with AgNPs. The

inhibitory activity of AgNPs on the P-gp protein efflux was compared with the effect caused by the

drug Verapamil. Further analyses on the transcriptional level of P-gp are ongoing. With this work we

are showing that AgNPs can modulate the functionality of the pump efflux protein P-gp that is

related with the MDR behavior in cancer.


BIO - 3


Characterization of bifenthrin nanoparticles synthesized by laser ablation of solids in liquids.

Enrique Camps [1]; M. Flores-Castañeda [1,3]; Enrique Campos-Gonzalez [1]; M. Patricia-Cruces [2]; Emilio Pimentel [2]; Irvin Ruiz-Aguilar [4]

ININ, Depto, de Física; ININ, Depto. de Biología; UAEM, Facultad de Química; Agricultura Nacional SA de CV

The Laser ablation of solids immersed in liquids (LASL) method was used for the synthesis of

nanoparticles of the insecticide known as “bifenthrin” in deionized water as liquid medium. The

effect of variations of the focusing lens-target distance and laser wavelength on the size, structure

and morphology of the nanoparticles was studied. A commercial bulk bifenthrin insecticide target

was elaborated for the ablation process. By means of Ultraviolet-visible (UV-Vis) absorption

spectroscopy, the characteristic absorbance spectra were analyzed, confirming the presence of

nanoparticles. Structural characterization and size determination were carried out by transmission

electron microscopy (TEM). The crystalline structure of the nanoparticles was studied by comparing

the interplanar distance of the nanoparticles determined by HR-TEM with the interplanar distances

of the bulk material observed in XRD. The nanoparticles sizes varied between 3 and 20 nm, with a

narrow size distribution. According to the results, both size and structure of the nanoparticles are

mainly determined by the incident energy density on the target, whilst wavelength affects

morphology. Males and females of Drosophila melanogaster were used in order to test the toxicity

of the obtained colloids. The results showed that the lethal dose can be achieved at short times with

significantly lower concentrations in comparison with doses commonly applied when bulk material

is used.


BIO - 4


Inhalable rutile nanoparticulate in atmospheric dust

*Gallego-Hernández, A.L. [1]; Meza-Figueroa, D. [2]; Pedroza-Montero, M. [1]

Departamento de Investigación en Física, Universidad de Sonora; Departamento de Geología, Universidad de Sonora

Particulate matter (PM) fraction is a heterogeneous mixture of gases and various types of liquid and

solid particles suspended in the air, originated from natural and anthropogenic sources. The size of

the particles has been directly linked to their potential for causing health problems, being ultrafine

(<0.1 μm or PM1.0) of particular interest among researchers due to the ability to penetrate the

tracheobronchial and alveolar regions after inhalation and get distributed to other organs.

PM1.0 breathable fraction was collected at the pedestrian level with a frmOMNI air collector located

at a high-traffic road intersection at the Sonora desert (Hermosillo, Sonora, México). Chemical

characterization was determined by Transmission Electron Microscopy (TEM) and Scanning Electron

Microscopy (SEM) couple to Energy-dispersive X-ray spectroscopy (EDS). The atmospheric sample

showed the presence of high concentrations of titanium (Ti), oxygen (O), carbon (C), silicon (Si),

among others. By Confocal Raman Microscopy and High Resolution-TEM, nanoparticles of rutile

crystals (TiO2) were identified, which represent a critical factor associated with cytotoxicity.

Additionally, the presence of the carcinogenic polycyclic aromatic hydrocarbons (PAHs) was also

detected. Analysis of collected road dust at the study site suggests that high rutile concentration is

deposited at street level, which can get into air circulation by vehicle and pedestrian traffic.

In order to avoid anthropogenic sources and cease the release of toxic nanoparticles to the

environment, it is important to understand the heterogeneity and complexity of ultrafine PM that

impact human population, a fundamental issue in the prevention of chronic diseases.


BIO - 5


NEW APPROACHES FOR NANOTOXICOLOGY EVALUATIONS: A THREE-DIMENSIONAL CELL CULTURE SYSTEM

Karla Juarez-Moreno* [1,2]; Rafael Vazquez-Duhalt [1]

Center of Nanosciences and Nanotechnology, National Autonomous University of Mexico; CONACYT.- Center of Nanosciences and Nanotechnology, National

Autonomous University of Mexico

Due to the wide use of nanomaterials it is mandatory to assure their biosafety in several biological

systems. To accomplish this, the in vitro cytotoxic effects of a given nanomaterial are typically tested

in a two-dimensional cell culture (2D). However, these models exhibit several limitations, the most

important is that the cells grow in a monolayer structure and they do not generate the same cellular

signals as those triggered in a three dimensional environment. To overcome this, herein we propose

a novel three-dimensional (3D) cell culture, called spheroids, as a representative approach for

nanotoxicological assessments. Thus, in this work we show the comparative cytotoxicity of three

different types of nanoparticles evaluated in both 2D and 3D cell cultures. The cellular effect of

metallic and non-metallic nanoparticles on 2D and 3D cultures of murine melanoma cancer cells and

mice fibroblasts cells are compared. Cell viability tests, apoptosis/necrosis determination, reactive

oxygen species generation, and uptake rate monitored by flow cytometry and confocal microscopy

are presented herein. We found that the 3D cell culture, where no scaffolds are needed, exhibits

differential cytotoxic susceptibility when compared with the 2D cultures. Our results indicated that

cells respond in a collective manner rather than in an isolated form. The main conclusion is that

cellular responses to nanomaterials change depending on the architecture of cultivated cells. This

approach will provide valuable information concerning the nanotoxicological impacts of biomedical

and biotechnological uses of nanomaterials and will allow performing better toxicological

evaluations similar or closer to the natural cellular responses obtained in in vivo assays.

Keywords: Nanotoxicology, bionanotechnology, spheroids, nanomaterials, cytotoxicity.


BIO - 6


Pegylated cyclodextrins: uncovering their nanoassemblies

Norma Jassel Ramírez-Rodríguez [1]; Salvador López Morales[1]; Manuel Alexis Torres-Mena [1]; Luis José López-Méndez [1]; Patricia Guadarrama[1]; Yareli Rojas-Aguirre[1] *

Instituto de Investigaciones en Materiales UNAM

βcyclodextrin (βCD) is a macrocycle that has been extensively studied for its capacity to form

inclusion complexes with hydrophobic bioactive compounds, modifying their aqueous solubility.

Due to their chemical versatility, βCD can be widely assorted with diverse moieties to tailor their

physicochemical properties and recognition abilities, thus improving their performance. βCD

derivatives are playing an important role in the development of nanosized drug delivery systems by

supramolecular design.

It has been reported that βCD and some of its derivatives have the capacity to self-assembly in

water, thus modifying their properties. Supramolecular βCD assemblies could comprise multiple

cavities, enhancing the host-guest complexation. Is well known that size and shape of

nanostructures determine their interaction with the biological surroundings, toxicity and

performance as delivery systems. Therefore, to investigate the size and architecture of βCD

nanoaggregates is of great importance. Moreover, the design of βCD-based nanoarchitectures with

predictable size and shape is still a challenge.

Our research group is engaged in the synthesis of βCD derivatives for their application in the

nanomedicine field. For this work, we have selected a pegylated βCD (βCD with 7 poly ethylene

glycol 5 kDa chains attached to its primary face, βCD-PEG5) to explore its self-assembly behavior

under different conditions. Thus, we present the synthesis, via click chemistry, of βCD-PEG5 and the

study of their nanoassemblies under different conditions of ionic strength, pH and temperature. The

outcomes indicate that the βCD-PEG5 aggregates result from a delicate balance of attractive and

repulsive forces. Therefore, the aggregation process will depend on the surroundings, which if

changed, will alter the supramolecular architecture of βCD-PEG5.


BIO - 7


A platform for the incorporation of proteins and peptides into genetically-encoded crystals

Sampieri Alicia, Adolfo Cruz, Zepeda Jesus and Vaca Luis

UNAM

Baculoviruses are widely used for the production of recombinant proteins, biopesticides and as gene

delivery systems. One of the viral forms called polyhedra has been recently exploited as a scaffold

system to incorporate or encapsulate foreign proteins or peptide fragments. However, an efficient

strategy for foreign protein incorporation has not been thoroughly studied. In the present work we

have developed a novel strategy to incorporate proteins into genetically-encoded nanoparticles

with very high efficiency.

The proteins incorporated into the crystal matrix are functional inside the crystal, maintaining

enzymatic activities and physical properties. Changes in pH induce the release of the proteins

contained in the crystal, to provide a delivery system with great control and accuracy.

We have tested this system to incorporate antigens of interest to produce novel vaccines, enzymes

for the industry and for the rapid development of diagnostic tools using solid state PCR reactions

with crystals containing selective DNA polymerasas within.


BIO - 8


Effect of an extra carbon source and inoculum in a biofuel cell with living hydrophytes

Salinas-Juárez M.G. [[1]*, Ramírez-Martínez S.A. [2], Cruz-Martínez H. [3], Durán Domínguez M.C. [2]

Facultad de Estudios Superiores Zaragoza UNAM; Facultad de Química UNAM, Departamento de Química Cinvestav

Biofuel cells with living hydrophites (BFC-LH) propose a potential instrument to supply electricity

from the photosynthesis of plants. BFC-LH were created to be fueled by plants, later, a wastewater

influent was included in order to remove pollutants. To determine the effects of an extra carbon

source and the inclusion of anaerobic microorganisms on the electrical generation and the COD

removal in a BFC-LH, an experimental system was build up with 10 reactors assembled with different

components. Some of reactors included synthetic wastewater, nutrient solution or tap water.

Reactors (2.65L) contained electrodes made with graphite felt. An inoculum (anaerobic sludge) was

introduced into the reactor. The plant and additional graphite granules were set above the anode,

and the cathode felt was placed on the surface of the recipient.

Open circuit voltage was measured and a variable resistor box (1-1000 Ω) was used to measure

voltage and current. The chemical oxygen demand (COD) was determined and tests of microbial

metabolism were realized. To observe the microorganisms on the electrodes, scanning electron

microscopy was performed for a sample of each electrode.

The biochemical analysis showed microorganism in every reactor, which had different

characteristics according to the oxygen availability in the reactor, to the plant presence, and to the

extra carbon source supplied. Micrographs showed microorganisms in reactors, the type of

microorganisms and the way in which they were arranged on the graphite support is different for

every reactor.

Wastewater in reactors promoted the current production. The highest current density produced

was 278.79 mAm-2. However power density increased with no extra carbon source; a 30.79

mWm-2 power density was recorded in reactor with no carbon source. Finally plant is important

for COD removal, reactors with plant showed the highest removal (81 % with an influent of 325

mgCOD/L).


BIO - 9


Enzymatic synthesis of indigo-derivative industrial dyes

Josemarco Mendoza Ávila [*, 1]; Karla Paulina Alejo González [2]; Rafael Vázquez-Duhalt [1]

UNAM; CICESE

Colouring materials are extensively used in the textile, leather, paper, rubber, plastics, cosmetics,

pharmaceutical and food industries. Indigo is one of the oldest known natural colouring material.

Indigo dye was originally obtained from plants and mollusks. However, today’s indigo demand is

largely met by synthetic indigo. Several methods have been proposed for indigo dye synthesis:

Baeyer-Drewson (1882), Heumann (1897) and Pfleger (1901), the latter being the first commercially

practical method. Nevertheless, the era of synthetic indigo has led to drawbacks associated with

dyestuff production ranging from costly reagents to environmental concern. Green chemistry

proposes as imperative to find new synthesis methods that should be environmentally friendly and

economically attractive. Accordingly, this work describes a novel route for enzymatic production of

indigo dye via hydroxylation of indole and indole derivatives. A variant of cytochrome P450 (CYPBM3

F87A) from Bacillus megaterium was used to catalyze indigo and three substituted indigo derivatives

synthesis: 4,4’-dibromo-indigo, 5,5’-dimethoxy-indigo and 7,7’-dimethoxy-indigo. Substrates used

were indole, 4-bromoindole, 5-methoxyindole and 7-methoxyindole. The reactions were performed

in aqueous, acetonitrile (ACN) and dimethylformamide (DMFA) solutions. In all the cases colored

products were obtained and the catalytic constants were determined. The chemical nature of the

obtained dyes will be elucidated by spectrometric techniques. Furthermore, the last goal of this

work is the effective covalent immobilization of CYPBM3 F87A on amino-functionalized magnetic

nanoparticles, in order to build a nanoreactor able to efficiently catalyze the production of indigo

dye and its derivatives. Enzymatic synthesis of industrial dyes seems to be an interesting alternative

to chemical synthesis with lower environmental impact.


BIO - 10


In vitro biocompatibility evaluation of europium-doped hydroxyapatite nanoparticles

Emmanuel Gaona-Carranza [*,1]; Karla Juárez-Moreno[1,2]; Fabián Martínez-Pallares[3]; Manuel Herrera-Zaldívar[1]; Olivia A. Graeve [3]

Centro de Nanociencias y Nanotecnología, UNAM; CONACYT Research Fellow at CNyN-UNAM; University of California, San Diego

Due to its good tissue response and osteoconductivity, hydroxyapatite (HA) has been used as a

scaffolding material for bone tissue engineering and coating for some biomaterials such as titanium

and zirconia. However, the conventionally prepared HA has a very different size from the natural

one, which is characterized by an oriented arrangement of nanometric particles. Greater mimicry

and osteoconductivity can be achieved if nanometric HA is used as a biomaterial. On the other hand,

it has been demonstrated that the use of rare earths in nanocrystals reduces reactive oxygen species

generation in human mesenchymal cells and fibroblasts.

Therefore, in this study, we evaluated the influence of europium-doped hydroxyapatite

nanoparticles (nHA:Eu) and undoped hydroxyapatite nanoparticles (nHA) with and without heat

treatment on the proliferation of mice L929 fibroblasts and MC3T3-E1 pre-osteoblasts. Murine

fibroblasts and pre-osteoblasts were cultivated on the surface of nHA and nHA:Eu discs then, cell

proliferation was evaluated by the reduction of resazurin to resorufin. To determine whether the

cell exposure to nHA or nHA:Eu induces any oxidative stress, the reactive oxygen species (ROS) was

measured by flow cytometry. Furthermore, the osteogenic differentiation of MC3T3-E1 pre-

osteoblasts exposed to 8 μg/mL of nHA:Eu or nHA was determined by qualitatively measuring the

quantity of alkaline phosphatase (ALP). Additionally, to perform a more complete nanotoxicological

evaluation of the nanoparticles, the biocompatibility and biosafety of both materials were evaluated

by a hemolysis test.

The results of our work, showed that nHA and nHA:Eu without heat treatment promote better

proliferation on both cell lines, L929 fibroblasts and MC3T3-E1 osteoblasts, nevertheless,

proliferation over the nanoparticles were lower than control culture. Due to growth inhibition, the

production of ROS was also diminished, besides it was demonstrated that the nanoparticle


BIO - 11


Physicochemical Characterization of Palladium nanoparticles using Polydatin

Alejandro Campa Rivera, Ericka Rodríguez León, César Rodríguez Beas, Aarón Martínez Higuera, Ramón A. Iñiguez Palomares

Posgrado en Nanotecnología, Departamento de Física, Universidad de Sonora.

Palladium nanoparticles with sizes ranging from 2-5 nm were synthesized by photochemical method

at room temperature using Polydatin which is composed by a glycoside resveratrol. The

Concentration of metallic precursor (1 mM de PdCl2) was maintained constant and Polydatin

concentration varied from 0.1 mM hasta 8 mM, also 4 different solvents combinations were tested:

Deionized water (DIW), Ethanol (98%) (EtOH), DIW: EtOH (70:30 v/v %) and EtOH:DIW (70:30 v/v

%). All the synthesis process took place at room temperature (RT). To determine nanoparticle

stability, zeta potential was measured at different polydatin concentrations and also for the distinct

solvents. The study measured formation kinetics for each solvent , the results showed that the faster

plasmon quenching is achieved in water, in the rate of seconds , on the other hand the slower

nanoparticles formation rate took place in Ethanol (EtOH), which lasted 48 hours. UV-Vis

Spectroscopy was performed, indicating a continuous Surface plasmon decrease as the

nanoparticles are formed, especially for sizes under 10 nm (1). In the case of the mixed solvents the

DIW:EtOH (70:30 v/v %) solution showed a faster nanoparticles formation compared to the

EtHO:DIW (70:30 v/v %). A microstructural study was performed showing an average 2nm

nanoparticle size using ethanol, and a 5nm spherical nanoparticles using water.

References

(1) Petla, R. K., Vivekanandhan, S., Misra, M., Mohanty, A. K., & Satyanarayana, N. (2012).

Soybean (Glycine max) leaf extract based green synthesis of palladium nanoparticles. J Biomater

Nanobiotechnol, 3(1), 14-19.


BIO - 12


BMV VLPs-Insulin

Daniel A. Escobedo-Rodriguez [1,2]; Ruben D. Cadena-Nava [1]

CNyN-UNAM; CICESE

Diabetes mellitus is a chronic disease of multiple causes. It is triggered when irregularities occur in

the action of insulin or its production through the pancreas, inducing an increase in blood glucose

levels. Patients suffering from this disease undergo treatments consisting of frequent administration

of exogenous insulin through subcutaneous, intramuscular or intravenous injections. Since it is a

long-term treatment, injections are not recommended as a method of administration, with the oral

route being the most favorable route of administration. However, insulin has low physicochemical

stability at low pHs, as it is in the gastric environment, and it is susceptible to degradation by

proteases throughout the digestive tract, and because of its hydrophilic nature it cannot be

absorbed in through the intestine. To overcome these obstacles, in the present work the insulin has

been efficiently encapsidated in BMV VLPs, consisting of assembled protein subunits that constitute

the viral capsid of the brome mosaic virus (BMV). The results obtained show that stable VLPs were

synthesized with monomeric insulin (its active form) in its interior, with an average diameter of 53

nm. The in vitro assays to evaluate VLPs-Insuin proteins integrity showed that are conserved until

after 1 hour in gastric conditions. In intestinal conditions about 50% of the content is lost after 1

hour, mainly due to the digestive enzymatic activity. All of this proves the stability of these

bionanoparticles and their capacity of being absorbed through the intestinal epithelium in this

period of time. This is the first work in which insulin is encapsulated in a VLP and its use can help to

improve the current therapies against diabetes.


BIO - 14


Characterization of polyethylene terephthalate (PET) nanoparticles and their toxicity evaluation in two cell lines in vitro.

Cristóbal, A. [*,1,2]; Rafael, V. [1]; Ana, R. [1]

UNAM; CICESE

The presence of micro and nano plastics in the marine environment is an alarming problem of

increasing importance (Barnes et al., 2009). Micro and nano plastics may have a negative impact on

animals, including human health (Fossi, 2012; Pham, 2017; Reynolds, 2018; ). As such, toxicity

evaluations for plastic nanoparticles are crucial. However, the extraction and purification of plastic

nanoparticles from marine sources is challenging, for which it is necessary to find useful synthesis

alternatives for toxicity evaluations. In this work we propose the synthesis of polyethylene

terephthalate nanoparticles (PET NPs) by means of laser ablation, as well as the evaluation of its in

vitro toxicity to identify their potential health risk. Characterization of PET NPs was carried out in

terms of physical/chemical properties. PET NPs obtained, had a diameter between 30-50 nm, a

homogeneous shape, and show FTIR peaks tied to commercial PET bottles. In vitro cell results

showed and effect on viability and proliferation for both HCT15 (Dukes´ type C, colorectal

adenocarcinoma) and Raw Blue (cells derived from the murine RAW 264.7 macrophages), after 24,

48 and 72 hours of incubation with PET NPs. Moreover, internalization of fluorescent PET NPs was

observed by confocal microscope for both cell lines with no morphological changes of cells.

However, PET NPs arouse the immune response of RAWBlue macrophages, by Toll-like receptors

(TLR´s) activation.

Authors appreciate technical support to Dr Katrin Quester, from Bio-nanotechnology lab CNYN-

UNAM and Dr Ceres Molina, from Aquaculture department CICESE.

References:

Barnes, D. , et al. Philosophical Transactions of the Royal Society B: Biological Sciences, 2009

Fossi, M. et al., frontier in Marine Science, 2012

Galgani, P., et al., frontier in Marine Science, 2017

Reynolds, C. et al., ELSEVIERE, 2018


BIO - 15


Citotoxicity effect of Co0.25Zn0.75Fe2O4 magnetic nanofluid on different tissues of Balb/c mice primary cultures

Espinosa-Villalpando, M. [1,*]; Blanco-Salazar, A. [1]; Arenas-Rodríguez, J. [1]; Cruz-Ramírez, O. [1]; Meneses-Sagrero, S.[2]; Aguilar-González, G.[3]; González-Vega, J.[3]; Valenzuela-Salas, L.[4]; Pestryakov,

A.[5]; López-Medina, J.[6]; Toledano-Magañ

Centro de Nanociencias y Nanotecnología; Universidad de Sonora-Departamento de Ciencias Químico Biológicas; Universidad Autónoma de Baja California;

Universidad Autónoma de Baja California-Escuela de Ciencias de la Salud Valle de las Palmas; Tomsk Polytechnic University; CONACyT-UNAM, Centro de

Nanociencias y Nanotecnología; Centro de Nanociencias y Nanotecnología-Departamento Físicoquímica de Materiales

Ferrofluids based on magnetic Co1-xZnxFe2O4 ferrite nanoparticles are colloidal systems of single

domain of magnetic nanoparticles with a mean diameter around 30 nm, dispersed in a polar or

nopolar liquid carrier. Recently ferrofluids have been the subject of interest because of their unusual

optical, electronic and magnetic properties, which can be changed by applying an external magnetic

field. The use of ferrofluids has expanded their applications in fields such as biomedicine, specially

as an alternative and localized treatment for malignant tumors. In this context, it should be taken

into consideration that for medical applications, these materials must be biocompatible with the

organism. In addition to this and the lack of a correct regulation of the nanomaterials toxicity, it is

extremely necessary that ferrofluids, as well as their applications, be safe both for the individuals

who use them and for the environment. Based on this, the primary cultures of specific tissues turn

out to be a good approximation to carry out cytotoxic studies of nanomaterials since they allow the

results to be extrapolated and, therefore, to approximate the behavior of these nanostructures in

more complex organisms.

In this work we present the results of the in vitro evaluation of the cytotoxicity effect of a ferrofluid

based on magnetic Co0.25Zn0.75Fe2O4 ferrite nanoparticles tested in primary cultures of healthy

BALB / c mice. The counts obtained using flow cytometry showed a low cytotoxicity of the ferrofluid

for the four dilutions used.

This work was partially supported by the International Bionanotechnology Network and Dirección


PE100318, PE101317 and FORDECYT - CONACYT 272894. Authors would like to thank valuable

technical support provided by Eloisa Aparicio, Eduardo Murillo, David Dominguez, Israel Gradilla,

Francisco Ruíz and Jaime Mendoza.


BIO - 16


Design micro-electro-mechanical systems (MEMS) variables of an air-microfluidic sensor for the study of particulate matter

Sharon Ezrre Gonzalez[*,1]; Marco Antonio Reyna Carranza[1]; Rosa Citlalli Anguiano Cota[2]; Heriberto Márquez Becerra[3]; Roberto López Avitia[1]

Cuerpo Académico de Bioingeniería y Salud Ambiental, Universidad Autónoma de Baja California. Calle Normal s/n, Parcela 44, CP 21100, Mexicali, B.C. México;

Facultad de Ingeniería, Universidad Autónoma de Baja California. Calle Normal s/n, Parcela 4, CP 21100, Mexicali, B.C. México; Departamento de Óptica, Centro de

Investigación Científica y de Educación Superior de Ensenada. Carretera Ensenada - Tijuana No. 3918, Zona Playitas, CP. 22860, Ensenada, B.C. México

Air pollution is becoming increasingly relevant, given the overwhelming scientific evidence on health

conditions in exposed populations. The sources of pollution can be natural and/or anthropogenic.

One of the most important pollutants usually is suspended particles, known as particulate matter

(PM), and its fractions known as inhalable: particulate matter (PM10), and breathable: fine

particulate matter (PM2.5, PM1.0) and ultra-fine particulate matter (PM0.1). The effects that PM

produces on human health are diverse and depend mainly on its chemical composition. For its

chemical characterization, samples are usually taken in the field and then taken to the laboratory.

In this work, it is proposed to analyze the chemical composition of PM in situ, by analyzing the

variables that would be required for the design and simulation of a microfluidic air sensor based on

the principles of flow cytometry using a micro-electro-mechanical system (MEMS), for the study of

PM2.5 and PM0.1 fractions. The design would also allow the separation by size of these fractions of

PM.

Key words: air pollution, particulate matter, MEMS, air microfluids.


BIO - 17


Enzymatic detoxification of endocrine disruptors

Santino J. Zapian Merino[1]; Rafael Vazquez-Duhalt[*, 1]

UNAM

Pollution is one of the main concerns and challenges in society. Domestic, commercial and industrial

activities deteriorate the environment and represent a public health risk. Among the different

chemicals involved in pollution, endocrine disruptor compounds (EDCs) have caught especial

attention due to their effects upon exposed organisms. EDCs directly interact with the endocrine

system of organisms, and exposure to these substances are related to male reproductive disruption,

early female puberty, leukemia, brain cancer, among others effects.

The cytochromes P450 are heme-containing proteins involved in the oxidative catalysis of multiple

substrates. Therefore, their role in the detoxifying process is significant, as they intervene in the

transformation of exogenous compounds also called xenobiotics.

In this study, the capability of a bacterial variant CYP called “F87A” was investigated in the

transformation of bisphenol A (BPA), resorcinol and, 17β-estradiol. The catalytic activities and the

reaction products were examined. Similar catalytic activities were found for the different EDCs due

to their comparable structures. Gas chromatography/mass spectrometry analysis was employed to

identify the oxidation products. A product from the enzymatic transformation of 17β-estradiol was

identified as [(16β, 17β)-16,17 epoxoestra-1,3,5 (10)-trien-3-yl]oxytrimetile.


BIO - 18


Green synthesis of silver nanoparticles by using strawberry (Fragaria ananassa) extract: Characterization and antibacterial activity

Daniela S. Chávez-Ramírez [*1]; B. Liliana España-Sánchez [1]; Linda V. González-Gutiérrez [1]

Centro de Investigación y Desarrollo Tecnológico en Electroquímica CIDETEQ. Parque Tecnológico Querétaro s/n, Sanfandila, C.P. 76703, Querétaro, México.

Synthesis of silver nanoparticles (AgNPs) has gained scientific interest due to their wide range of

applications and development of advanced technologies, especially as suitable antimicrobial agent1.

The conventional physical and chemical methods to synthesize silver nanoparticles require the use

of organic solvents, stabilizers and reducing reagents, which can cause several health and

environmental effects associated to their toxicity 1. We report a green method for the synthesis of

silver nanoparticles by in situ reduction of metallic precursor (AgNO3) using strawberry (Fragaria

ananassa) fruit extract as reducing agent, under different conditions such as temperature and

reactants amount. Morphology, size, stability, crystalline structure and chemical state of AgNPs

were characterized by TEM, UV-Vis, Zeta potential, XRD and XPS analyses. A FTIR analysis was done

to identify the functional groups present in the phytoconstituents of the fruit extract as responsible

for the synthesis of AgNPs. These AgNPs have an average size of ~ 5-20 nm, spherical shape, and

show good stability, indicated by zeta potential values from -30 to -40 mV. In addition, the obtained

AgNPs showed high bactericidal activity against pathogenic microorganisms such as E. coli, P.

aeruginosa and S. aureus. This method is an easy and eco-friendly process for AgNPs synthesis with

potential application as antimicrobial agents.

Keywords. Silver nanoparticles, green synthesis, antibacterial effect, strawberry extract.

Acknowledgments. We would like to thank to p.I.Q. Hellen Bañuelos Rivera for her technical support

for antimicrobial assays and to I.B.Q. Ma. Lourdes Palma Tirado for her technical support in TEM

image analysis.

References.

Siddiqi, K. S., Husen, A., & Rao, R. A. K. (2018a). A review on biosynthesis of silver nanoparticles and

their biocidal properties. Journal of Nanobiotechnology, 16(1), 14.

Corresponding author. [email protected]


BIO - 19


Machine Learning to Identify Luminescent Nanoparticles in Cancer Cells

Dora-Luz Flores [*,1,3]; Gustavo A. Hirata [2]; Michelle Digman [3]

Facultad de Ingeniería, Arquitectura y Diseño, Universidad Autónoma de Baja California, Ensenada, Mexico; Centro de Nanociencias y Nanotecnología, Universidad

Nacional Autónoma de México, Ensenada, Mexico; Department of Biomedical Engineering, University of California Irvine, Irvine, USA

The great amount of information that is obtained when carrying out different measurements of

optical microscopy in the area of medicine is a challenge for its analysis and interpretation and is

often underexploited. There are proposals to reduce the time of data processing and help in decision

making to experts. The complexity in the interpretation of the information increases when there are

images of biological tissues or even more of complete organs, and also a real-time response is

necessary. The machine learning (ML) techniques for medical imaging and many other biomedical

applications have been successfully employed. This powerful analysis methodology plays an

important role for computer-aided diagnosis.

The nanoparticles have been used as nanocarriers for the administration of drugs must overcome

numerous barriers including external, route and cellular aspects to finally reach their function that

is the release of the drug in the indicated place. To trace the route of drug release with a nanocarrier,

different biomedical imaging techniques have been used, e.g. fluorescence-lifetime imaging

microscopy (FLIM), from which a large amount of information is obtained. In this project, ML

techniques are proposed to analyze data obtained using FLIM from luminescent nanoparticles in

living cells.

Acknowledgments.

The experiments reported in this publication were performed at the Laboratory for Fluorescence

Dynamics (LFD) at the University of California, Irvine (UCI). The LFD is supported jointly by the

National Institute of General Medical Sciences of the National Institutes of Health (2P41GM103540),

and UCI. The content is solely the responsibility of the authors and does not necessarily represent

the official views of the National Institutes of Health. We would like to thank Rachael Cinco-Hedde

and Milka Stakic (UCI-LFD laboratory) for the FLIM measurements and cell culture, respectively.


BIO - 20


Molecular modeling simulation studies reveal new potential inhibitors against HPV E6 protein

Joel Ricci [1,2]; Abraham Vidal [1]; Matías Zuñiga [3]; Verónica Jiménez [3]; Joel Alderete [4]; Sergio A. Águila [1]; Carlos A. Brizuela [2]

UNAM; CICESE; UNAB; UdeC

High-risk strains of human papillomavirus (HPV) have been identified as the etiologic agent of some

anogenital tract, head, and neck cancers. Although prophylactic HPV vaccines have been approved;

it is still necessary a drug-based treatment against the infection and its oncogenic effects. The E6

oncoprotein is one of the most studied therapeutic targets of HPV, it has been identified as a key

factor in cell immortalization and tumor progression in HPV-positive cells. E6 can promote the

degradation of p53, a tumor suppressor protein, through the interaction with the cellular ubiquitin

ligase E6AP. Therefore, preventing the formation of the E6-E6AP complex is one of the main

strategies to inhibit the viability and proliferation of infected cells. Herein, we propose an in silico

pipeline to identify small-molecule inhibitors of the E6-E6AP interaction. Virtual screening was

carried out by predicting the ADME properties of the molecules and performing ensemble-based

docking simulations to E6 protein followed by binding free energy estimation through

MM/PB(GB)SA methods. Finally, the top-three compounds were selected, and their stability in the

E6 docked complex and their effect in the inhibition of the E6-E6AP interaction were corroborated

by molecular dynamics simulation. Therefore, this pipeline and the identified molecules represent

a new starting point in the development of anti-HPV drugs.


BIO - 21


Nanotechnology to the Rescue of a Proudly Mexican Plant: Vanilla

Bello-Bello, J.J.[1]; Espinosos-Castillo, J.L.[2];Arano-Avalos, S.[2];Martínez-Estrada, E.[2]; Arellano-García, E.[3];Pestryakov, A.[4];Toledano-Magaña, Y.[5];Casillas-Figueroa, F.[6];García-Ramos,

J.C.[5*];Bogdanchikova, N.[6];

CONACyT-Colegio de Postgraduados-Córdoba; Colegio de Postgraduados-Córdoba; Facultad de Ciencias-UABC; Tomsk Polythecnic University; CONACyT-CNyN-

UNAM; Escuela de Ciencias de la Salud-UABC Valle Dorado; CNyN-UNAM

Worldwide demands of Vanilla planifolia lead to finding new options to produce large-scale and

contaminant-free crops. Particularly, the Mexican Government has classified Vanilla planifolia at risk

and is subject to protection programs since wild species are in danger of extinction and no more

than 30 clones have been found. Nanotechnology could help to solve both demands and genetic

variability, but toxicological concerns must be solved. In this work, we present the first study of the

cytotoxic and genotoxic effects promoted by AgNPs in Vanilla planifolia plantlets after a very long

exposure time (six weeks).

Our results show that Vanilla planifolia plantlets growth with doses of 25 and 50 mg/L is favored

with a small decrease in the mitotic index. A dose-dependency in the frequency of cells with

chromosomal aberrations and micronuclei was found. However, genotoxic effects could be

considered as minimum due to with the highest concentration employed (200 mg/L), the total

percentage of chromatic aberrations is lower than 5% with only three micronuclei in 3000 cells,

despite the long-time exposure to AgNP.

Therefore, 25 and 50 mg/L (1.5 and 3 mg/L of metallic silver) were identified as safe concentrations

for Vanilla planifolia growth on in vitro conditions. Exposure of plantlets to AgNPs increase the

polymorphism registered by inter-simple sequence repeat method (ISSR), which could be useful to

promote the genetic variability of this species.

Furthermore, AgNPs formulation plant-biocompatibility was determined through exposure of

Allium cepa (model recommended by the OECD to determine cytotoxic and genotoxic effects) to

similar concentrations used on Vanilla. Results showed that even higher concentrations of this

AgNPs formulation, such as 100 ug/L, can be considered as safe for plants.

Authors acknowledge CONACyT Red International de Bionanotecnología 293418 for financial

support and Red Farmoquímicos 294727 for critical review.


BIO - 22


Interaction of silver nanoparticles with boilogical systems in vitro (Entamoeba histolytica)

Perrusquía-Hernández Jesús David [1]; Néquiz-Avendaño Mario [1]; Pestryakov Alexey [2]; Toledano-Magaña Yanis [3]; García-Ramos Juan Carlos [3]; Bogdanchikova Nina [4]

UNAM; Hospital general de México "Eduardo Liceaga"; CNyN; CONACyT; TPU

Amebiasis is currently, and for last years, one of the most frequent diseases in Mexican population

and people in developing countries. To date, the number of patients and incidence per year are

increasing despite of existing treatments.

There exist two forms of disease, intestinal and extraintestinal, being the first one the most frequent

in child population, and the second one in adult-geriatric population.

Nowadays, there are several drugs against amebiasis that can help treat this problem, however it’s

been reported in many publications that drugs used tend to be harmful to health. Mainly reported

as hepatotoxic and nephrotoxic and sometimes considered as carcinogenic.

The use of Silver nanoparticles (AgNPs) in this experiment is justified due to the effectiveness shown

in combating other diseases such as tuberculosis, lung cancer and other parasitosis as

trypanosomiasis or leishmaniasis.

The main objective of this experiment is to demonstrate that AgNPs have a significant effect in the

reduction of the proliferation of throphozoites of Entamoeba histolytica in in vitro models, to detect

morphological changes that cells present in the presence of the compound and with this, to

determinate an IC50 (inhibitory concentration 50) and thus be able to evaluate damage caused by

AgNPs.

The effects were evaluated at three different concentrations 3, 6 and 12 μg/mL by optical

microscopy using Trypan blue vital stain in a Neubauer chamber.

So far, we have demonstrated that AgNPs present activity from the intermediate concentration (6

μg/mL) inducing parasites dead and morphological changes.

AgNPs present an inhibitory and antiproliferative effect in trophozoites of Entomoeba histolytica

when they are exposed to AgNPs for 72 hours in anaerobic conditions, in a dose-dependent manner.

Acknowledgments

This work was supported by Red Internacional de Bionanotecnología 293418 and Red

Farmoquímicos 294727 (CONACyT).


BIO - 23


Antimicrobial properties of ZSM-40 type zeolite functionalized with silver ions and silver nanoparticles

Roberto González-Orozco[*,1]; Magali Mendoza[2]; Karina V. Chávez[3]; V. Soto[3]

División de Ingenierías; Microbiología Sanitaria Unidad de Vinculación; Laboratorio del Estado Sólido, Departamento de Química, Centro Universitario de Ciencias

Exactas e Ingenierías, Universidad de Guadalajara Blvd. Marcelino García Barragán 1421, C.P. 44430 Guadalajara, Jalisco México.

Recently, the development of antibacterial materials has been used, with special reference to those

containing silver. Silver has been used as one of the strongest antibacterial agents since the time of

ancient Greece [1]

K. Rieger et al., Reported antimicrobial activity of silver ions in Zeolites immobilized in

cellulose nanofibers [2]. In addition, H. Can et al. studied the effect of space between silver

nanoparticles on their antimicrobial effect [3]. P. López et al. they synthesized a cluster of 29 silver

atoms with antibacterial and antifungal properties [4].

In this work we report the antimicrobial activity of Zeolite ZSM-5 (Si / Al = 40), exchanged

with silver ions and enriched with silver nanoparticles of different size. The synthesis of the

nanoparticles is carried out by reduction of silver cations exchanged previously.

Acknowledgments

We would like to thank the Solid State Laboratory and the University of Guadalajara.

References:

1. M.J Sanchez et al., The Journal of Material Letters C, 191, 65-68 (2017).

2. K.A. Rieger et al., ACS Applied Materials & Interfaces C, 8, 3032-3040 (2016).

3. H. Cao et al, The Journal of Physical Chemistry Letters C, 5, 743-748 (2014).

4. P. López et al, ACS Applied Materials & Interfaces C, 1, 1595-1602 (2018).


BIO - 24


In vitro cytotoxicity of Protein-Coated Silver Nanoparticles on Mice Primary Cultures

Blanco-Salazar ALBERTO [*,1]; Espinosa-Villalpando MARÍA FERNANDA [1]; Rodríguez-Arenas JOSÉ ANTONIO [1]; Santiago-Solís ALBERTO [1]; Rodríguez-Marino LUIS RICARDO [1]; Mendoza-Ávila

JOSEMARCO [1]; Meneses-Sagrero SALVADOR [2]; González-Vega JESÚS GABRIEL

CNyN-UNAM;UNISON;UABC;TPU;CONACyT-UNAM-CNyN

Silver nanoparticles are one of the fastest growing nanomaterial categories for consumer and

biomedical applications. Nowadays, AgNPs are present in various healthcare products but without

official regulation for their use. Their unique physicochemical characteristics along with their

antimicrobial ability make AgNPs a high demand material in different sectors. Despite their

demonstrated benefits, recent studies have reported on the toxicological effects of AgNPs.

Therefore, the enormous applications of AgNPs raise concerns about human exposure. This

emphasizes the need for identifying their toxicological effects in order to prevent possible adverse

effects in human exposed. Thus, toxic effects of nanomaterials need to be known before AgNPs

appliance into the biomedical field.

Because of their dimensions, nanoparticles substantially increase their reactivity producing

beneficial effects with lower concentrations and shorter times. However, also may bypass natural

mechanical barriers, disrupting the structure and function of several cellular structures and in turn,

interfere with very important metabolic processes. Hence, use of primary cells isolated from target

tissues is desirable for cytotoxic evaluations, as the first step to simulate more closely the cellular

response to these nanomaterials.

In this work, we evaluate the cytotoxic response of different concentrations of protein-coated

AgNPs against healthy BALB/c mice primary culture of spleen, liver, kidney, bone marrow, heart and

aorta cells. Cell viability was determined by flow cytometry. Also, morphology changes on the cells

were determined with an optical microscope adding trypan blue. In general, no cytotoxic effects

were observed at the concentrations evaluated in the different mice primary cultures selected for

this study.

Authors acknowledge Red Internacional de Bionanotecnología 293418 and Farmoquímicos

293418 from CONACyT for the financial support.


BIO - 25


CYTOTOXIC EFFECT OF 5 DIFFERENT SILVER NANOPARTICLES IN VITRO ON MICE LIVER, SPLEEN, BONE MARROW, AORTA, KIDNEY AND HEART PRIMARY CULTURES

Rodríguez-Arenas José A. [*,1]; Blanco-Salazar Alberto [1]; Espinosa-Villapando María F. [1]; González-Vega Jesús G. [2]; Cruz-Ramíres Omar U. [1]; Aguilar-González G. [2]; Valenzuela-Salas Lucía M. [1];

Meneses-Sagrero Salvador [3]; Pestryakov Alexey[4];

CNyN-UNAM; UABC; UNISON; TPU; CONACYT-UNAM;

Silver nanoparticles (AgNPs) have great demand in research, consumer products and biomedical

applications due to its optical, conductive and medical properties. However, concerns have been

expressed about their possible adverse effects on human health.

In vitro cytotoxic studies are often used as initial characterization of biological response to AgNPs

exposure and these are useful to identify the associated hazards. Primary cell culture is described

as a good model for cytotoxic assays since they resemble tissue environment and sensitivity.

Nanomaterial physicochemical properties as size (diameter), surface area, surface charge, redox

potential, surface functionalization and composition play a key role in development of cytoxicity. In

general, AgNPs shows dose-dependent cytotoxic effect in monocytes and are toxic for brain, lung,

liver, skin, kidney, and reproductive system.

In this work we evaluate in vitro cytotoxicity of 5 new formulations of AgNPs that involve PVP of

different molecular weight on murine liver, spleen, bone marrow, aorta, kıdney and heart primary

cultures. Cells were isolated from BALB/c mice according to NOM-062-ZOO-1999, purified, and

seeded whit supplemented RPMI 1640 or DMEM and exposed for 24h to different concentration of

new AgNPs formulations. For cytotoxic assay, 50’000 cells per well were used. Finally, cell viability

was determined by flow cytometry using Thermo Fisher Scientific Attune NxT Acousting Focusing

Cytometer and the Attune NxT Autosampler.

Results show non-cytotoxic response for any formulation assayed in this cellular model even in the

higher concentration used 100 μM (content of metallic Ag). The lack of cytotoxicity in these primary

cultures are the first step in the completeness of toxicological profile of new AgNPs formulations

and suggests a good potential for next steps toward its biomedical applications.

Authors thank to CONACyT through: Red Internacional de Bionanotecnología 293418 and Red

Farmoquímicos 294727.


BIO - 26


Proposal of a new Antipsychotic derivative of clozapine absent of cardiometabolic side-effects by means of in silico methods

Alma C. Castañeda Leautaud ; Abraham Vidal Limon ; Carlos A. Brizuela Rodriguez ; Sergio Aguila Puentes

CICESE; CNyN-UNAM;

The high dropout of drug treatments for schizophrenia is due to the adverse cardiometabolic effects

that include obesity, tachycardia and the propensity to suffer from diabetes mellitus type 21. The

computer aided drug design or in silico methods are among the more efficient regarding time and

money than the traditional approaches2. The aim of this project is to design a new antipsychotic

drug candidate with the ability to reduce the adverse cardiometabolic effects that most drugs of

this type induce. Our research focuses on the study of dynamic interactions of two G-protein

coupled receptor complexes (GPCR), namely Dopamine D2 and Histmine H1 receptors in complex

to commercial drug clozapine as lead compound, since this drug has managed to improve the

symptoms of schizophrenia in most patients, even those with refractory schizophrenia3. The aim of

this work is to propose a derivative of clozapine using the molecular dynamic simulations and free

energy perturbation methods (FEP) to calculate theoretical affinities between the GPCR involved in

the effectiveness and the side effects.

We have constructed and validated our GPCR in complex to clozapine and results of intermolecular

interactions are discussed.

ACKNOWLEDGEMENTS

We gratefully thank to CICESE-UNAM Nanoscience Master program, CNyN-UNAM, CONACyT

scholarship No. 756788, LANCAD-UNAM-DGTIC-286 and LANCAD-CINVESTAV-Xiuhcoatl Hybrid

Cluster grants.


BIO - 27


Silver Nanoparticles Efficiency in Diabetes Foot Ulcers Treatment in Private Health Services at Ensenada, Baja California, in the Period August-December 2018

Cesar A.[1];Bogdanchicova N. [2];Luna R.[3];Aracely R.[4]

CLINICA INTEGRAL AVANZADA ENSENADA B.C.; UNAM; UABC;UABC

Diabetic foot is a collateral pathology on type II Diabetes Mellitus patients, being one of the major

complications of the disease worldwide, in Mexico occupies the second place. Nowadays, 6 to 8 of

every 100 diabetic patients suffer an amputation, and 85% of them lose a foot.

The aim of this work was validating the efficacy and efficiency of silver nanoparticles application for

the treatment of ulcerous lesions of diabetic patients.

The methodology employed consisted of the medical monitoring of nine patients under the same

intervention protocols performed in a private health clinic . The curative procedures are performed

daily applying silver nanoparticles of different concentration and presentation in function of the

severity of the ulcer.


NPh - 1


Design and fabrication of Al2O3 slab optical waveguides by Atomic Layer Deposition using H2O and O3 as reactants.

D. L. Caballero Espitia [*,3]; E. G. Lizárraga Medina[1];Hugo Tiznado Vázquez[1]; Georgina Navarrete Alcalá[2]; Heriberto Márquez Becerra[2]

Centro de Nanociencias y Nanotecnología Universidad Nacional Autónoma de México. Km 107 Carretera Tijuana-Ensenada. Ensenada, Baja California, México. CP

22860; Centro de Investigación Científica y de Educación Superior de Ensenada. Carretera Ensenada - Tijuana No. 3918, Zona Playitas, CP. 22860, Ensenada, B.C.

México. ; Posgrado en Nanociencias: Centro de Investigación Científica y de Educación Superior de Ensenada. Carretera Ensenada - Tijuana No. 3918, Zona Playitas,

CP. 22860, Ensenada, B.C. México.

In the search for integrated optics technologies required by functional scale-reduced systems,

development of waveguiding structures in micro and nanoscale is critical. This work presents the

design and fabrication of Al2O3 thin film based waveguides grown by Atomic Layer Deposition

(ALD). Two fabrication groups with a thickness between 500 nm and 1000 nm are shown: the first

one using H2O as reactant and the second one using O3. Physical and optical properties where

obtained by means of Scanning Electron Microscopy, Atomic Force Microscopy and Variable Angle

Ellipsometry and the obtained results were used to calculate the waveguide properties on MATLAB

simulations. The optical waveguide characterization is based on measurement of the effective

refractive index by a prism coupling technique and propagation loss coefficient by fiber-waveguide

coupling. The same characterizations were made for both fabrication lines in other to make a

comparison between optical and structural properties obtained in each reactant variation.

Acknowledgments

We acknowledge to PAPIIT (Grants No. IN-110018, IN-112117 and IA-101018), PAPIME (Grants No.

PE-100318 and PE101317), FORDECyT (Grant No. 272894) and CONACyT (Grant No. 632147), as well

as Israel Gradilla Martínez, Msc. Jorge Jurado González, David Dominguez and Jessica Angel for their

technical support.

References

1. López, J., et al., Al2O3-Y2O3 ultrathin multilayer stacks grown by atomic layer deposition as

perspective for optical waveguides applications. Optical Materials, 72, 788-794. (2017)


NPh - 2


Geometric phases in photon shuttle optomechanical system

D. Morachis Galindo* [1]; J. Maytorena Córdova [1]

Centro de Nanociencias y Nanotecnología, UNAM

Quantum optomechanics paves the way towards quantum control of mechanical motion via

radiation pressure interaction and may also be used to test quantum mechanics at the mesoscopic

level. On the other hand, geometric phases offer an interesting way of understanding both classical

and quantum phenomena and represent a promising tool for quantum computation. Our system

consists of an optical cavity lased from one side which contains a moveable dielectric membrane

inside. We consider membrane's position and phase shift as control variables which form closed

paths in parameter space and calculate the corresponding geometric phase; it is shown that the

geometric phase is related to the expectation value of the photon number of the left side of the

cavity. The relation between the geometric phase acquired by the photon field and the transmission

properties has been studied.


NPh - 3


TDDFT study of excited states of Br2 in clathrates cages

Cercis Morera-Boado [*,1]; M. I. Bernal Uruchurtu [1]; R. Hernández-Lamoneda [1]

Centro de Investigaciones Químicas, UAEM

The ultraviolet and visible spectra of halogen clathrates have been the subject of several

experimental studies [1,2]. The main interest in the structure and physicochemical properties of

these cages relies on the remarkable potential applications in energy and environment, in addition

to open questions in basic science. The most extensive and detailed experimental information about

these systems have been obtained for bromine, where UV-vis spectra were analyzed for

polycrystalline tetragonal structure and cubic simple samples among other phases. A large and

characteristic blue-shift have been obtained, which is characteristic of halogen bonding and can be

understood in terms of simple molecular orbital concepts. Ab initio calculations have been

extensively used in order to reproduce experimental shifts, and guest-host intermolecular potentials

for ground and excited states of bromine inside clathrate cages [3]. However, the search for a less

computationally demanding method that allows exploring the dynamics of the Br2 inside the 51262

particular cage as well as its UV-vis spectra introduces us to Time Dependent Density Functional

Theory (TDDFT). Therefore, we use TDDFT with different density functionals ranging from m-GGAs

to Hybrid and Range Separated Hybrid (RSH) types to understand the electronic shifts, the halogen

bonding and the dynamics of Br2 inside the 51262 particular cages. Some preliminary results

indicate the good performance of RSH density functionals in reproducing experimental and ab-initio

calculated electronic shifts. In addition, the electronic shifts are clearly related with the appearance

of halogen bonding.

1. G. Kerenskaya et. al., J. Phys. Chem. A 110, 13792–13798 (2006).

2. G. Kerenskaya et. al., J. Phys. Chem. A 11, 10969–10976 (2007).

3. R. Hernandez-Lamoneda et. al., J. Phys. Chem. A 112, 89–96 (2008).


NPh - 4


Characterization of nanolaminated slab optical waveguides

E. G. Lizarraga-Medina* [1]; D. L. Caballero-Espitia [1,2]; J. Jurado [1,2]; H. Marquez [2]; J. López [1,3]; H. Tiznado[1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, B.C. – México.; Centro de

Investigación Científica y Educación Superior de Ensenada - CICESE, Ensenada 22860, México; CONACYT - Centro de Nanociencias y Nanotecnología, Universidad

Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, B.C. – México.

Atomic layer deposition is a precise and conformal technique that has shown its value on

nanolaminated fabrication by combining 2 different materials. Changes in the nanolayers

thicknesses of each material result in refractive index control that can be used to tailor optical

waveguide properties by using the nanolaminate as a core. In this work, Al2O3-Y2O3 nanolaminates

with different nanolayer thicknesses were fabricated, the increase of the Y2O3 nanolayer resulted

in higher propagation losses at the 632.8 nm wavelength. Obtained results allowed to determine an

yttrium concentration limit, and hence refractive index, for feasible optical waveguides aimed at

integrated optics applications.


PAPIME (Grants No. PE-100318 and PE101317), FORDECyT (Grant No. 272894) and CONACyT (Grant

No. 632147), as well as David Dominguez and Jessica Angel for their technical support.


NPh - 5


Chitosan modifications to get an electroluminescent material

Marlon G. [*, 1]; Gema G. [1]; Juan L. [1]

School of Physical Sciences and Nanotechnology, Yachay Tech University, Urcuqui, Ecuador

Chitosan is a natural polymer derived from chitin which is biodegradable and biocompatible. CS is

very abundant, has no toxicity and has a good film formation. An important property is the degree

of deacetylation that indicates the amount of free amino groups which controls the ability of the

polymer to combine with many metal ions. One of its applications is to stabilize fascinating photonic

materials such as semiconductor nanoparticles, organic fluorescent dyes, transitional luminescent

complexes and lanthanides. The purpose of this work is to modify chitosan with different

compounds and nanoparticles, in order to increase the ion conductivity and its electroluminescence

properties. In the present work, we prepare chitosan membranes with lithium addition in different

concentrations, additionally we added ZnO Nanoparticles to the membranes with and without

lithium. The ionic conductivity was measured by complex impedance. The results obtained suggest

that these membranes have a potential as electrolyte and luminescence polymers for different

applications.


NPh - 6


Design of integrated optical components for quantum devices on a silicon nitride platform

N. A. Barboza[*,1,2];K. Garay-Palmett [3]; W. De La Cruz [1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, 22860, Ensenada, B.C., México;Escuela de Ciencias de la Ingeniería y

Tecnología, Universidad Autónoma de Baja California, Blvd. Universitario No. 1000, Valle de las Palmas, Tijuana, B.C., C.P. 21500, Mexico;Departamento de Óptica,

Centro de Investigación Científica y de Educación Superior de Ensenada, B.C., 22860, México

Optical waveguide technology has emerged as a promising tool for the development of quantum

information processing systems. It has been shown that quantum circuits with a high level of

integration can be developed on silicon photonics architectures [1]. This type of circuit requires the

integration of several elements that perform specific functions such as filtering, coupling,

polarization and phase control, among others. These components are essential for interconnecting

the different stages in a quantum device, for example, generation and interference of single

photons. For a specific device funcionality, both passive and active optical components must be

implemented.

Particularly in this work, we present a design proposal of an integrated optical filter based on

waveguide directional couplers, which has been engineered such as it can be integrated later in a

device for the generation of photon pairs by spontaneous four wave mixing. In the first stage of our

work, we aim to separate two optical signals tuned at 800 and 1550 nm. The chosen material for

designing and fabrication of our quantum devices is silicon nitride, which is a transparent material

at visible wavelengths and exhibits a high nonlinear refractive index [2]. The proposed filter will be

fabricated by photolithography techniques at a later stage.

To design the optical filter, we used a simulation software for photonic devices. In this process the

optimal parameters of waveguides and directional couplers are determined, such as the distance

between two arms of a coupler, their length, the cross-sectional area of waveguide, among others,

so that each element works properly.

References

1. J. W. Silverstone, et. al., IEEE J. Sel. Top. Quantum Electron. 22, 390-402 (2016).

2. A. R. Johnson et al., Opt. Lett. 40, 5117-5120 (2015).


NPh - 7


Light Emission Properties Characterization of 2D Heterostructure Layered Materials (WS2 and MoS2) by Confocal and Scanning Near Field Optical Microscopy

F. A. Domínguez-Serna[1*]; A. Meza-Olivo[2]; D. Robles-Gutiérrez[3]; W. De La Cruz[4]; N. Perea-López[5]; K. Garay-Palmett[2]

CONACYT – Centro de Investigación Científica y de Educación Superior de Ensenada, B.C., 22860, México; Departamento de Óptica, Centro de Investigación

Científica y de Educación Superior de Ensenada, B.C., 22860, México; Facultad de Ciencias, Universidad Autónoma de Baja California, Ensenada, B.C., 22860,

México; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, 22800, Ensenada, B.C., México; Department of Physics, The

Pennsylvania State University, University Park, Pennsylvania 16802, United States

Mono and few layered materials formed by transition metal dichalcogenides (TMDs) present

interesting physical properties with no counterpart found in the bulk medium [1], among them,

higher nonlinearities result of particular interest [2]. Recently, heterostructured materials at the few

layers level are gaining attention as they present many tunable properties. For bi-layered

heterostructured, the emission spectra can be tuned given physical relationship among both layers

that could be their relative orientation. Heterostructured materials can also be used as a single

photon emitters with an enhanced and tunable emission [3].

In this work of employ mono and bi-layers of WS2 and MoS2 synthetized by chemical vapor

deposition. We study the photo-luminescence (PL) enhancement properties of the layers by a

confocal transmission microscopy set up, as well as by Scanning Near Field Optical Microscope.

Spectral data in different spatial regions relative to the center of the samples has already been

collected. We observe for WS2 a spectrum centered at 646 nm for incident radiation close to center,

which moves towards lower wavelengths and up to about 630 nm, also wider emission bandwidths

are observed as long as the incident laser gets off center and closer to the edges. A spatially resolved

PL map has been collected for both WS2 and MoS2 monolayers in the confocal set-up up to now,

which is consistent with higher emission close to the edges of the sample. Finally, the scanning near

field optical microscopy (SNOM) allows for acquisition of PL maps with resolutions beyond

diffraction limit. Preliminary SNOM-collected images are shown as an effort to discover high

emission rate zones, and defects that could serve as single photon emission centers.

References

[1] H. R. Gutiérrez, et. al., Nano Lett 13, 3447-3454 (2013)

[2] C. Torres-Torres et. al., 2D Mater. 3, 021005 (2016)

[3] W. Zheng, et. al., Adv. Optical Mater 1800420 (2018)


NPh - 8


Light driven nanoparticles as photonic motors

Germán Morales-Valenzuela*[1]; Rubén D. Cadena-Nava[2]; Víctor Ruiz- Cortés[1]

CICESE; CNyN

The use of light as the main source for the manipulation of particles, cells and proteins is of great

interest in different areas of current research: in the biomedical area for the transport of drugs [1]

and in biology to study the interaction between cells [2].

Single-beam trapping is a well known technique that uses optical radiation pressure to control and

manipulate microscopic particles that since its publications by Ashkin et al in 1987 [3], has became

an increasingly useful tool in a variety of applications in biology, micro-fluidics, near-field

microscopy, etc. A different approach was used by Kawata and Sugiura [4]. They observed particle

movement in the evanescent field of a laser beam. This technique allows simultaneous optical

manipulation of a large number of particles over an extended area. Guiding and trapping particles

using near-field and evanescent optical forces has been a very active field and several configuration

have been used, such as guiding dielectric and metallic nano- and micro-particles in an extended

homogeneous evanescent field.

In this research work, we report a series of experiments related with the movement of dielectric

and biological florescent nanoparticles by evanescent waves, those waves were created on the

surface of a semi-cylindrical prism using the condition of total internal reflection with an s and p

polarized incident beam. We observed a difference of speeds that correspond to different

polarizations. The movement of the nano-particles generated by the evanescent waves was studied

by recording, with an optical system, the fluorescence of the nanoparticles.

Abdelmohsen, L. K. E. A., Peng, F., Tu, Y., & Wilson, D. A. (2014). J. Mater. Chem. B, 2(17), 2395–

2408.

Zhang, H., & Liu, K. K. (2008). Journal of the Royal Society Interface, 5(24), 671–690.

Ashkin, A. (1970). Physical Review Letters, 24(4), 156–159.

Kawata S. and Tani T. (1996), Opt. Lett. 21, 1768–1770.


NPh - 9


Second harmonic generation response from gold metallic nanoprism arrays under focused illumination

K.Y. Raygoza-Sánchez [1]; Rocha-Mendoza [1]; P. Segovia [2]; A.V. Krasavin [3]; G. Marino [3]; T. Cesca [4]; N. Michieli [4]; G. Mattei [4]; A. V. Zayats [3]; and R. Rangel-Rojo[1]

Optics Department and ; Researcher of Cátedras CONACYT, Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana,

No. 3918, Zona Playitas, 22860 Ensenada B.C., Mexico ; Department of Physics and London Centre for Nanotechnology King’s College London, Strand, London WC2R

2LS, UK ; Dipartimento di Fisica e Astronomia Galileo Galilei, Università degli Studi di Padova, Padova, Italy

In this work we report a study of the second harmonic generation (SHG) of light in hexagonal arrays

of gold nanoprisms as a function of the polarization orientation of light, using femtosecond pulses.

The gold nanoprism arrays were manufactured using the nanosphere lithography technique. SHG

experiments were conducted in a transmission mode using a focused beam to excite the sample at

normal incidence. The fundamental light was generated by a Ti:Sapphire oscillator (Coherent Mira

900) pumped at 532 nm. The oscillator produces ultrashort 90 fs linearly polarized pulses at a 76

MHz repetition rate. The pulses had a spectral width of 17 nm and were centered at an 810 nm

wavelength. The SHG signal shows an a dependence with input polarization angle with hexagonal

symmetry, attributed to the strengthening of the local field by the nano-antenna effect obtained for

polarizations coinciding with the symmetry axes of the array. Numerical simulations show the

relationship between the geometry of the sample and the dependence of the SHG signal with

polarization. Simulations show an enhancement of the field at these angles, and we believe that

enhancement is responsible for the increased SHG observed at certain angles.


NPh - 10


Silicon nitride optical waveguides for quantum optics applications

A. L. Aguayo-Alvarado [*, 1]; S. Álvarez-Ortega [2]; W. De La Cruz [2]; K. Garay-Palmett[1]

Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Tijuana-Ensenada No. 3918, A. Postal 360, 22860, Ensenada B.C.,

Mexico; Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 Carretera Tijuana-Ensenada, C.P. 22860, Ensenada B.C.,

Mexico

The implementation of efficient and on demand non-classical light sources in integrated photonic

circuits is essential for the development of quantum technologies. The generation of two-photon

states as well as heralded single photon states is feasible from the spontaneous four wave mixing

(SFWM) process in optical waveguides, which can be fabricated by photolithography techniques and

based on materials that exhibit high third-order nonlinearity, such as silicon nitride (Si3N4). This

material can be synthesized in the form of thin films by ionic erosion, laser ablation and atomic layer

deposition techniques.

In this work, we propose the implementation of SFWM in ridge waveguides of Si3N4 on substrates

of Si and SiO2. Si3N4 is a transparent material at optical wavelengths and exhibits a third-order

electrical susceptibility higher than that of SiO2. Using the MODE Solution package from

LUMERICAL, the propagation constant of the fundamental mode of waveguides with rectangular

cross-section were calculated. The waveguide dimensions were varied in the ranges 0.2 - 0.8

microns (waveguide height, the film thickness) and 0.6 - 3.0 microns (waveguide width). From the

calculated waveguide dispersion, the phasematching properties required for the SFWM process

were studied. It was found that in the considered parameter ranges become possible to generate

SFWM photon pairs and in different spectral regions (determined by the waveguide cross section)

and exhibiting different spectral correlation properties. The specific degree of correlation is

determined by the excitation wavelength, which can be accessed from a tunable Ti: Sapphire laser.

The present work constitutes a prelude to the development of integrated photonics devices for the

generation and manipulation of single photon states.


NPh - 11


Two-photon absorption of ZnO nanoparticles synthesized by laser ablation of solids in liquids

Dannareli B. [1*];Israel R. [1];Santiago C. [1]

Centro de Investigación Científica y de Educación Superior de Ensenada

We report the study of ZnO synthesized by laser ablation of solids in liquids, and their subsequent

optical and morphological characterization. The colloidal suspensions of NPs were obtained using

a solid zinc target, acetone as a liquid medium and nanosecond pulses from a Nd: YAG laser (with a

wavelength of 532nm and a repetition frequency of 15 Hz). The UV-Vis absorption spectrum shows

a peak at 345 nm. TEM micrographs demonstrate a core-shell morphology, with diameters between

5 and 20 nanometers. The fluorescence induced by absorption of two photons of the colloid samples

showed a quadratic dependence to the excitation power.


NPh - 12


Nanopartículas y medio quirales orgánicos con poder óptico rotatorio para la modificación de la birrefringencia de fibras de cristal fotónico de núcleo hueco

Arroyo E. [*, 1], Tentori D. [1], Garcia A. [1], Olivas A. [2], M. Farfán [1].

CICESE; UNAM

Cuando un rayo de luz natural incide sobre cualquier medio refringente (con un índice de refracción

mayor, como el paso de un rayo de luz del aire a un medio sólido como el vidrio), se verifica una

polarización de la luz. Todos los cristales que no pertenecen al sistema regular (sistema cúbico)

exhiben el fenómeno de la doble refracción: un rayo de luz que penetra en un cristal de este tipo se

divide en dos.

En una fibra óptica común el fenómeno de reflexión interna total permite guiar la luz de un

punto a otro y hace que la birrefringencia residual sea muy sensible al perfil de su sección

transversal, lo que se conoce como birrefringencia geométrica. Por otra parte, en una fibra de cristal

fotónico, la luz queda confinada en el núcleo debido a la estructura de huecos de la cubierta, que

genera una banda fotónica. Esta forma de guiado ha permitido el desarrollo de fibras de cristal

fotónico de núcleo hueco.

En el presente trabajo tiene como objetivo síntetizar y preparar soluciones ópticas de

nanopartículas de estructura cristalina hexagonal y medios líquidos quirales orgánicos que exhiban

birrefringencia circular. Ademas, inducir actividad óptica en fibras de cristal fotónico de núcleo

hueco, evitando la contribución de la birrefringencia geométrica, con la ventaja adicional de que la

magnitud de esta birrefringencia circular podrá variarse al modificar la concentración de

nanopartículas quirales. La finalidad es ampliar la capacidad de estas fibras para ser usadas como

sensores.


PCNN - 1


Improved colloidal synthesis of Ni and Co metal nanoparticles to catalyze selectively hydrodeoxygenation of C4-C5 oxygenates

Mikhail Simonov [*, 1]; Alina Yaroslavtseva [2]; Irina Simakova [1]; Yuliya Demidova [1]; Andrey Simakov [3]

Boreskov Institute of Catalysis, pr. Ak. Lavrentieva, 5, Novosibirsk, 630090, Russia; Novosibirsk State Technical University, 630073, pr. K. Marksa, 20, Novosibirsk,

630090, Russia; Centro de Nanociencias y Nanotecnología de la Universidad Nacional Autónoma de México, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja

California, México

A rational control of nanoparticles (NPs) characteristics can be achieved through regulation of the

synthesis conditions. Ni and Co are widely used as an industrial hydrogenation/hydrodeoxygenation

catalysts. Supported Ni and Co metal NPs are anticipated also to be of potential interest as

inexpensive catalytic materials for hydrodeoxygenation of lignocellulose derived oxygenates [1]:

levulinic acid (LA) and unsaturated crotonaldehyde (CA).

In the present work Ni and Co NPs with controllable sizes were prepared by a facile modified polyol

method utilizing polyvinylpyrrolidone (PVP) as a capping agent with a high metal/PVP ratio.

Ni and Co NPs were prepared by the improved polyol method. Nickel and cobalt chlorides in

ethylene glycol (Ru/PVP = 1:5) were reduced by NaBH4 at 7-170°C during 1 h. Ni and Co colloids as

well as NPs immobilized on the mesoporous carbon support and alumina were analyzed by a variety

of physical methods including TEM, XPS, XRF, UV-Vis.

TEM showed that the average diameter of Ni NPs increased from 2.6 to 3.2 nm when the reduction

temperature increased from 23 to 140ºC. For Co NPs the temperature increase from 7 to 23ºC

resulted in an increase in Co NPs size from 1.8 to 2.6 nm, whereas a further change from 23 to 100ºC

had a less significant effect on the metal particle size. In the case of Ni colloids an oxidative

atmosphere promoted formation of larger NPs with a wider particles size distribution compared to

those formed in the inert gas atmosphere. Immobilization of Ni and Co NPs colloids over supports

was found to be accompanied with NPs oxidation. Different reduction conditions of prepared

carbon supported NPs were applied to study formation of metallic NPs. Reduction conditions

provided acceptable cluster sintering for Ni/C and Co/C catalysts.

Acknowledgments

This work was supported by RFBR Grant 18-53-45013 IND_a.

References

1. Y. Demidova, I. Simakova, I. Prosvirin, D.Y. Murzin, A. Simakov, Int. J. Nanotechnology, 2016, 13,

3-14.


PCNN - 2


Rational design of highly active layered double hydroxides for electrocatalytic water oxidation

Ricardo Valdez [1,* ; Jesús David Yong [1]; Noe Arjona [2]; Amelia Olivas[1]

Centro de Nanociencias y Nanotecnología-UNAM, C.P. 22800 Ensenada B.C. Mexico; Centro de Investigación y Desarrollo Tecnológico en Electroquímica, C.P. 76703

Querétaro, Mexico

The design of competent nanomaterials for water oxidation (2 H2O → O2 + 4H+ + 4e−) is usually

projected to have enhanced electrocatalytic properties, the desired morphology, and specific

crystalline structure [1]. To develop reliable artificial photosynthesis devices, we should overcome

the sluggish anodic reaction, water oxidation [2]. Iridium oxide is an efficient catalyst, but this is not

affordable for large-scale applications. Some research groups are devoting huge efforts to provide

highly active catalysts based on third-row transition elements for the water oxidation. In this work,

we proposed the electrochemical activation of CoNi complex in alkaline electrolyte and the

synthesis of layered double hydroxides of NiFe doped with carbon quantum dots to enhance their

electrocatalytic properties toward water oxidation. We started from a facile one-pot synthesis

method of CoNi LDH@CoNi complex. Then, we separated both phases into CoNi LDH and

hexammine-nickel (cobalt) chloride [Co-Ni(NH3)6]Cl2 by centrifugation. Linear voltammetry pointed

out the CoNi complex performed an overpotential of ~279 mV, which is lower than both pure CoNi

LDH and CoNi LDH@CoNi complex. After the reaction, the CoNi complex is activated to CoNi LDH

phase, which presented higher catalytic performance. Besides, we determined that NiFe LDH doped

with CQDs exhibited a low overpotential of ~224 mV in water oxidation. The results obtained in this

work, open the door to a potential application of the synthesized materials in the fields of materials

science and electrocatalysis.

Acknowledgments

The authors thank E. Aparicio, E. Flores, J. Mendoza, F. Ruiz, and D. Domínguez from CNyN, and to

Luis Gradilla from CICESE.

References

1. R. Valdez, D.B. Grotjahn, D.K. Smith, J.M. Quintana, A. Olivas, Int. J. Electrochem. Sci, 10 (2015)

909–918.

2 S.L.Y. Chang, et al., Role of Advanced Analytical Techniques in the Design and Characterization of

Improved Catalysts for Water Oxidation, 2013, pp: 305.


PCNN - 3


OBTENCIÓN Y CARACTERIZACIÓN DE COMPOSITOS DE TiO2-ZEOLITAS

J. Alvarado [CIDS-BUAP*], K. M. Alvarez [CIDS-BUAP], M. A. Hernández [Zeolitas-BUAP], Susana Soto [CIDS-BUAP], Vitalii Petranovskii [CNIN]

CIDS-BUAP; Zeolitas-BUAP; CNIN

El TiO2 es un semiconductor utilizado en la fotocatálisis debido a sus propiedades ópticas y

eléctricas, mientras que las zeolitas se utilizan como fotocatalizadores debido a su estructura porosa

que permite una adecuada adsorción, combinando estos compuestos se crean materiales

avanzados. En este trabajo, las nanopartículas de TiO2 y los compuestos de TiO2-Zeolie se sintetizan

mediante el método sol-gel. La estructura compuesta es confirmada utilizando Difracción de Rayos-

X (DRX), Infrarrojo por Transformadas de Fourier (FTIR) y Raman. La prueba UV-vis se utiliza para la

investigación de TiO2 y TiO2-Propiedades ópticas de la zeolita. Las técnicas EDS, SEM y TEM se

utilizan para nanocompuestos sintetizados. Investigación de la morfología. Los resultados muestran

que las propiedades ópticas de la zeolita TiO2 aumentan con la incorporación de zeolita en TiO2.


PCNN - 4


Synthesis, Characterization and Catalytic Properties of Dandelion Flower like NiYMo Catalysts

Chowdari Ramesh Kumar*, Jorge Noé Díaz de León, Sergio Fuentes Moyado

Universidad Nacional Autonoma de Mexico, Centro de Nanociencias y Nanotecnologia, Km. 107 Carretera Tijuana-Ensenada, 22800 Ensenada, Baja California,

México

Globally the environmental legislations urge refineries to produce ultra low sulfur fuels.1 Refractive

sulfur compounds present in crude oil distillates are benzothiophene (DBT) and its derivatives.2

Industrially, sulfur compounds present in distillates are removed by hydrodesulfurization (HDS)

process. The main objective of the present work is synthesis of trimetalic (NiYMo) catalyst with

hollow interior with high surface area for the HDS of model compound DBT. The metal oxide catalyst

was synthesized by hydrothermal method. The synthesized catalyst was thoroughly characterized

by various techniques. Catalytic activity measurements were performed in a batch Parr reactor at

320 ⁰C. The BET analysis results showed that catalyst exhibited high surface area, 144 m2/g with a

pore diameter of 3.8 nm. From the FE-SEM analysis it was observed that catalyst particles are like

sphere in shape with nano sheets forming arrays on the particles surface. Hollow nature of the

particles was confirmed by TEM analysis. XRD analysis of the catalyst confirmed presence of mixed

oxide phases. Various oxidation species present in oxide and sulfided samples were confirmed by

XPS. The catalyst activated at 350, 400 ⁰C was evaluated for HDS of DBT and found that conversion

was 98.6 and 94.6%, respectively. However, there was no significant change in product selectivity.

These results indicated that the optimum catalyst activation temperature is 350 ⁰C. The selectivity

towards over hydrogenated products indicates that reaction proceeds mainly through the

hydrogenation route irrespective of the reaction temperature. Catalyst with dandelion flower like

hollow spheres has potential advantages in hydrotreatment of biomass to fuels, which has great

interest in recent years.

References

1. US EPA, Diesel Fuel Quality: Advance Notice of Proposed Rulemaking, EPA420-F-99-011, Office of

Mobile Sources, May 1999.

2. J.N. Díaz de León, Ch. Ramesh Kumar, J.A. García, S.F. Moyado, Catalysts 2019, 9(1), 87.


PCNN - 5


The inclusion of iron into zeolite framework instead of aluminum: the influence of synthesis conditions

L. Pelaez [1], Y. Kotolevich [2], Y. Yesqueda [2], F. Castillon [2], C. López Bastidas [2], I. Rodriguez-Iznaga [3], S. Fuentes [2], V. Petranovskii [2]

Universidad Tecnológica Fidel Velázquez, Nicolás Romero, 54400, México; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México,

Ensenada, 22860, México; Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Habana, 10400, Cuba

In our previous study, it was found that, under certain processing conditions, an isomorphous

replacement of tetrahedral aluminum atoms in the zeolite skeleton with ferric atoms, which adopt

the same tetrahedral configuration, occurs.

In the present work, the conditions for the synthesis of this new material have been studied in detail.

Monometallic and bimetallic samples of Cu, Fe, and Cu-Fe supported on mordenite were prepared,

in which the valence state of iron was variable. As a precursor, the 0.5 N aqueous solutions of CuSO4,

FeSO4, and Fe2(SO4)3 were applied. The samples under study were prepared by the microwave-

assisted ion exchange method. The effect of the pH of the precursor solution and the effect of

microwave treatment were investigated. Then the prepared samples were treated in a hydrogen

flow at 150, 250 or 450 °C for 2 hours.

This work is focused on the spectroscopic characterization of the formation of an Fe-modified

mordenite framework according to the results of Raman scattering, XPS and UV-Vis spectroscopy.


PCNN - 6


THE EFFECT OF IRON VALENCE ON THE PROPERTIES OF A COPPER-IRON BIMETALLIC SYSTEM SUPPORTED ON MORDENITE

L. Pelaez [1], Y. Kotolevich [2], Y. Yesqueda [2], R. YocupicioYocupisio [2], M.A. Estrada [2], T.A. Zepeda [2], I. Rodriguez Iznaga [3], S. Fuentes [2], V. Petranovskii [2]

Universidad Tecnológica Fidel Velázquez, México City, Nicolás Romero, 54400, México; Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma

de México, Ensenada, 22860, México; Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Habana, 10400, Cuba

The properties of zeolites can be precisely adjusted by changing the chemical composition of their

framework. In the present work, the mordenite was used in the sodium form, with a SiO2/Al2O3

molar ratio of 13. Monometallic and bimetallic samples containing Cu, Fe, and Cu-Fe with different

valence states of iron were prepared using the microwave-assisted ion exchange method. As a

precursors, the 0.5 N aqueous solutions of CuSO4, FeSO4, Fe2(SO4)3 were used. The obtained

samples were reduced in a hydrogen flow at 450 °C.

It is known that the cations in the zeolite framework compensate for the negative charge in the

lattice, and therefore their content should correspond to the amount of aluminum in the lattice.

Only such cations (Na+, Cu2+, Fe2+, Fe3+ and H+) remain in the composition of the sample, and the

sum of their positive charges divided by the aluminum content can be called the Equilibrium Ion-

Exchange Modulus (EIEM), and it should be equal to one.

The chemical composition of the samples showed that for monometallic Cu- and Fe(II)- containing

samples, EIEM is equal to 0.7 while for Fe(III)- containing samples EIEM reaches 1.5 due to a

decrease in Al content and an increase in Fe(III) content. This may mean that instead of ion exchange

with Na+, Fe (III) is incorporated into the zeolite lattice by displacing Al. These modifications to the

framework can have a significant impact on both the chemical and physical properties of zeolites.

From a chemical point of view, most changes in the catalytic and sorption properties can be

considered as a result of a variation in the overall electronegativity of a solid. Another important

result of such treatments are physical changes, such as thermal stability and pore volume, which are

the result of both changes in the framework and also the concomitant formation of extra-framework

species. Further, the structural, adsorption, electronic and catalytic properties of the materials

obtained will be considered.


PCNN - 7


Synthesis of G-ZnO composite thin films for improved photovoltaic performance in solar cells.

Raquel Ramírez Amador.[1,3*]; Leonardo Morales de la Garza. [2]; Salvador Alcántara Iniesta.[1]; Gregorio Flores Carrasco.[1,4]; Joaquín Alvarado Pulido. [1]; Julio F. Curioca Vega.[3]; M. García-Miranda.

[3]; H. P. Martínez-Hernández. [3]; Juan Balcón C

Centro de Investigación en Dispositivos Semiconductores (CIDS-ICUAP), Benemérita Universidad Autónoma de Puebla (BUAP); Universidad Nacional Autónoma de

México, Centro de Nanociencias y Nanotecnología; Universidad Tecnológica de Huejotzingo (UTH); University Carlos III of Madrid and IAAB, Dept. of Materials

Science and Engineering and Chemical Engineering, Madrid, Spain.

This work reports a study of synthesis of Graphene(G)-ZnO(Zinc Oxide) composite and films

deposited by Pneumatic Spray Pyrolysis (PSP) technique. G-ZnO composite was prepared by an

aqueous chemical solution. The films,of a ~225 nm thickness, were deposited on p-silicon substrates

at 460°C. The samples were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy

(SEM), UV-Visible Spectroscopy, I-V measurements and Hall Effect techniques. XRD results revealed

that the G-ZnO thin films were polycrystalline with a hexagonal wurtziteZnO phase with preferential

orientations along (002) planes. SEM studies showed that morphology of ZnO thin films was affected

by the incorporation of graphene. The calculated grain mean sizes were 50-55 nm. The optical gap

of G-ZnO thin films was from 3.35 to 3.38 eV range. Films revealed a value of resistivity

approximately (6.8x10-3Ω.cm).

The high-conducting and transparent-elaborating G-ZnO thin films may have several promising

applications due to its multifunctional properties, in this case it is presented a study to be used in

solar cells.

Acknowledgments

R. RamírezAmador acknowledges the financial support CONACYT by a doctoral scholarship and the

facilities given by VIEP-BUAP and CIDS-ICUAP. Also, the authors would like to thank the facilities

given by the Department of Electronic of the INAOE and laboratory equipment of department of

Nanocharacterizationof CNyN-UNAM.

References

[1] Gupta, A., &Srivastava, R. (2018). Zinc oxide nanoleaves: A scalable disperser-assisted

sonochemical approach for synthesis and an antibacterial application. Ultrasonics sonochemistry,

41, 47-58.

[2] Shuai, W., Hu, Y., Chen, Y., Hu, K., Zhang, X., Zhu, W., ...& Lao, Z. (2018). Journal of

Semiconductors, 39(2), 023001

[3] Chang, D. W., Choi, H. J., Filer, A., &Baek, J. B. (2014). Journal of Materials Chemistry A, 2(31),

12136-12149


PCNN - 8


Synthesis and characterization of MFI type zeolite doped with TiO2, and its subsequent evaluation in the photocatalytic degradation of dyes.

A. Urtaza[*, 1]; R. I. Yocupicio[1]; H. Borbón[1]; S. Fuentes[1]; V. Petranovskii[1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, Baja California, C.P. 22860, México

Zeolites are porous crystalline solids whose pores are of molecular dimensions thereby providing

size and shape selectivity for guest molecules. Zeolites are widely used in catalysis as well as in the

separation and purification fields due to their uniform, small pore size, high internal surface area,

flexible frameworks, and controlled chemistry [1]. In this study, we report the synthesis of four

samples of MFI type zeolite with Si/Ti ratios = 94, 47, 23.5 and 15.66 obtained by the hydrothermal

method and using sodium silicate (Na2SiO3) and sodium titanate (Na2TiO3) as sources of Si and Ti

respectively. Also, MFI zeolite was synthesized with Si/Ti ratio = 47 using TEOS and TEOTi as sources

of Si and Ti respectively to evaluate the change in the isomorphic substitution degree by each route

of synthesis. Samples were analyzed by different techniques such as UV-Vis spectrophotometry, N2

adsorption-desorption, X-ray diffraction, infrared spectroscopy and were tested in the

photocatalytic degradation of dye. The results displayed a decrease of textural properties (surface

area and micropore volume) with decrease of Ti while a segregation of TiO2 phase was obtained

with the increase of Ti.

References

1. Tao, Y.; Kanoh, H.; Abrams, L.; Kanako, K., Chem Rev, 106, 896-910 (2006).


PCNN - 9


SnOx thin films by magnetron sputtering dc varying the partial pressure of oxygen for their use in p-n junctions

Angélica Garzón Fontecha[*,1,2]; Wencel De La Cruz [2]

Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Tijuana-Ensenada 3918, C.P. 22860, Ensenada B.C., Mexico; Universidad

Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, km. 107 Carretera Tijuana-Ensenada, C.P. 22860, Ensenada B.C., Mexico.

Tin oxide has been widely used for the fabrication of transparent and flexible devices because of its

excellent optical and electronic properties. In this work, we grew SnOx thin films on glass by

magnetron sputtering dc. The carrier polarity of the thin films changed from p-type to n-type by

increasing the oxygen partial pressure (ppO2) from 6 to 18.5% and varying the working pressure

between 1.8 and 2.5 mTorr. In addition, these samples were heated at 180 °C for 30 min to

improving their crystalline structures. ITO thin films deposited by magnetron sputtering were used

as the contacts of SnO films. X-ray diffraction analysis corroborated the SnOx formation with a

tetragonal structure after the heat treatment. The p-type SnOx thin films were obtained in a ppO2

range from 6% to 9%; when the ppO2 was increased to 18.5%, the SnOx thin film showed n-type

behavior and a mobility of 22.2 cm2/Vs. The p-type SnOx semiconductor thin films have been

obtained for the fabrication of p-n junctions with application in transparent and flexible electronics.

Acknowledgments

We would like to thank E. Aparicio, E. Murillo, I. Gradilla, and H.Castillo for valuable technical

assistance. AGF received a Scholarship from CONACyT and DGAPA No. IN112918 grant. Authors

thank Laboratorio Nacional de Nanofabricación for its facilities for the development of this work.

References

1. Z. Wang, P.K. Nayak, J.A. Caraveo-Frescas, H.N. Alshareef, Adv. Mater. 2016, 28 (20) 3831–3892.

2. E. Fortunato, R. Barros, P. Barquinha, V. Figueiredo, S.-H.K. Park, C.-S. Hwang, R. Martins, Appl.

Phys. Lett. 2010, 97 (5), 521051–5.

3. J. A. Caraveo-Frescas, H.N. Alshareef, Appl. Phys. Lett. 2013, 103 (22), 222103–222105.


PCNN - 10


SYNTHESIS OF C-DOTS FROM GRAPE FRUIT, USING GREEN NANOTECHNOLOGY BY ASSISTED MICROWAVE TECHNIQUE.

Ortiz González K. Getsemani[1]; Flores-Lopéz Lucía Z [1]; Rivero Espejel, Ignacio A[1]; Espinoza Dueñas, Karla A[1];*

INSTITUTO TECNOLÓGICO DE TIJUANA

In the present decade, green nanotecnology has captured the attention of chemists for benign

technical, clean and sustainable. Not only does it lead to clean and more efficient processes, it has

also proven to be a low-cost process, in addition to eliminating environmental risks due to the

excessive use of precursors. Therefore, green nanotechnology promotes the design of chemical

products and environmentally benign chemical processes (1).

The Carbon Dots (C-Dots) are promising as a competitive alternative for quantum dots based on

heavy metals and organic dyes. Unlike other fluorescent materials that may need expensive

precursors or complex equipment and treatment processes, C-Dots can be easily prepared. One of

the techniques used in the synthesis of C-Dots is the microwave synthesis method. The microwave

synthesis method effectively reduces the reaction time and provides a simultaneous and

homogeneous heating that leads to good yields of C-dots productions. The microwave technique is

a powerful tool in green chemistry nanotechnology.

In the present work, C-Dots were prepared and characterized using natural and commercial grape

juice, using the microwave technique. The optimization tests and the conditions (time and

concentration) were carried out. The use of the microwave technique allowed the reduction of the

reaction times and provided an optimal heating, which allowed to obtain the C-Dots. The materials

were characterized by techniques as infrared, ultraviolet, fluorescence spectroscopy, and FESEM.

The obtained results showed the photoluminescent C-Dots with good yields in very shorts time and

mild conditions in comparison with the other methods reported. A higher quantum yield was

obtained for the carbon points produced by sources of commercial grape juice.

Bibliography

1. Debjani N., Pratyusha B., Env. Tox. And Pharm. 2013, 36(3), 997-1014.

2. Wang R.; Qiangl L.K.; Rong T.Z. Jun X.Y., J. Mater. Chem. A. 2017, 5, 3717


PCNN - 11


Promoting the catalytic activity from pure Pd nanoclusters to M@PdPt (M=Co, Ni Cu) core-shell nanoclusters for the oxygen reduction reaction

H. Cruz-Martínez [1*]; M. M. Tellez-Cruz [2]; O. Solorza-Feria [2]; D. I. Medina [1]; P. Calaminici [2]

Tecnologico de Monterrey, School of Engineering and Sciences, Atizapán de Zaragoza, Estado de México, C.P. 52926, Mexico;Departamento de Química,

CINVESTAV, Av. Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, Ciudad de México, C.P. 07360, Mexico

The trend of the catalytic activity toward the oxygen reaction reduction (ORR) from Pd44

nanoclusters to M6@Pd30Pt8 (M = Co, Ni, and Cu) core-shell nanoclusters was investigated using

the auxiliary density functional theory. The adsorption energies of O and OH were computed as

predictors of the catalytic activity toward the ORR. Besides, the stabilities of the M6@Pd38 and

M6@Pd30Pt8 core-shell nanoclusters were investigated through segregation energy. Using the O

and OH adsorption energies, the following tendency of the electrocatalytic activity toward the ORR

was computed: M6@Pd30Pt8 > M6@Pd38 > Pd44. In addition, the M6@Pd30Pt8 and Pt44

nanoclusters can present similar ORR catalytic activities. From the calculated segregation energies

for the bimetallic and trimetallic nanoclusters, it can be clearly observed that the M atoms prefer to

be in the center of the M6@Pd38 and M6@Pd30Pt8 nanoclusters. Therefore, the formation of core-

shell structures is favored in these systems.


PCNN - 12


Platinum sulfides: Synthesis, characterization and performance towards ORR

A. Sigüenza Orozco* [1]; G. Alonso-Núñez [2]; M.T. Oropeza-Guzmán [3]; Y. Gochi-Ponce [3]

Tecnológico Nacional de México - Instituto Tecnológico de Oaxaca; Centro de Nanociencias y Nanotecnología-UNAM; Tecnológico Nacional de México - Instituto

Tecnológico de Tijuana

Proton exchange fuel cells (PEMFC) are an alternative for clean energy generation. These devices

transform the chemical energy to electricity by a redox reaction carried out on the electrodes

surface of the cell, PEMFC's performance is limited by the cathodic oxygen reduction reaction (ORR),

since this reaction is slower than the anodic oxidation of hydrogen, hence, the use of an efficient

electrocatalysts is a key component in these systems.

Platinum chalcogenides have been reported as efficient catalysts towards ORR (Alonso-Vante), the

aim of this work is to evaluate the physical and electrochemical characteristics of platinum sulfides

synthesized by different methods.

Platinum sulfides were obtained by three methods: solvothermal reaction (PtS/N-CNTO), sulfuration

of N-CNT supported Pt (PtS/N-CNTU) and chemical reduction at 1:1 and 1:3 stoichiometric ratio

(PtS1:1/N-CNT and PtS1:3/N-CNT, respectively), N-doped carbon nanotubes (N-CNT) were used as

support, the platinum content was calculated of 20 wt%. Physical characteristics of these materials

were analyzed by X-Ray diffraction (XRD), scanning electron microscopy (SEM), and transmission

electron microscopy (TEM), it was found that the cooperite phase of platinum sulfur was formed

accompanied by crystalline platinum, and that the particle dispersion of the catalyst PtS/N-CNTO

was optimal.

The electrochemical behavior of materials was analyzed in acidic media by cyclic voltammetry (CV)

and linear sweep voltammetry (LSV) techniques, under inert atmosphere and oxygen saturated

atmosphere, respectively. CV and LSV analysis showed a lower response of PtS/N-CNT U compared

to other materials, it was also found that the variation of the stoichiometric ratio of Pt and S in

materials PtS1:1/N-CNT and PtS1:3/N-CNT affects the electrocatalytic behavior, finally CV indicates

that PtS/N-CNTO presents the best electrocatalytic response, while LSV confirmed that this material

shows the best behavior towards ORR.


PCNN - 13


Order determination of the ionic exchange equation in the zeolite (ZSM-5 Si/Al = 40) system and AgNO3 solution, varying temperature

Carlos Francisco Covarrubias Sánchez[*,1]; Maite Rentería-Urquiza[1]; Karina V. Chávez[1]; V. Soto.[1]

Laboratorio del estado sólido, Departamento de Química, Universidad de Guadalajara, Blvd. Marcelino Garcia Barragán 1421, C.P. 44430, Guadalajara, Jalisco,

México.

Zeolites are crystalline nanoporous inorganic materials formed by TO4 tetrahedra (T = Si, Al, P, etc.),

which show widespread applications in many industrial processes, such as heterogeneous catalysis

mainly [1]. The +3 charge belonging to the Al atoms inside the zeolite structure make it have a –1

negative charge, so it is required the presence of external cations to maintain a global charge of

cero. These external cations are exchangeable giving interesting chemical properties to these

materials [2]. Ionic exchange data is obtained by mixing a measured quantity of zeolite and an

aqueous solution for a period of time at constant temperature. Both phases are then separated, the

remaining solution is then analyzed in order to know the total Ag+1 concentration that was not

exchanged [2]. It is mentioned in literature that the global order of the cationic exchange equation

has a value of one, but we consider that because of the particular structure of each type of zeolite

and the Si/Al ratio, this order must be experimentally determined for each type of zeolite [3].

Knowing the cationic exchange kinetics equation will allow us to manipulate the amount of

exchangeable silver at different times. This will allow us to control the size of silver nanoparticles

obtained when a reduction process of the system takes place. In this work it is intended to find an

equation that allows us to do what mentioned above, this is done by performing the exchange

reaction at room temperature and 10 ºC.

Acknowledgement

Solid State Laboratory and technical support from the Chemical Analysis Laboratory

References

1. Sels, B. & Kustov, L. (2016). Zeolites and Zeolite-like Materials. Amsterdam, Netherlands: Elsevier.

2. Auerbach, S., Carrado, K. & Dutta, P. (2003). Handbook of Zeolite Science And Technology. New

York, U.S.A: Marcel Dekker.

3. Malherbe Rolando. Física química de las zoelitas, La Habana, CENIC-MES, 1988.


PCNN - 15


NANOESTRUCTURED NiW CATALYSTS FOR 3-METHYL THIOPHENE HYDRODESULFURIZATION

Cesar H [1]; Rafael H [1]; Ramesh Ch. [2]; Yasmin E. [2]; Gabriel A. [2]; Sergio F. [2]; J.Noé D. [*,2]

UMSNH; UNAM;

Ultra low sulfur fuels can be produced by deep removal of sulfur compounds from fossil fuels that

requires a hydrodesulfurization (HDS) process which is generally carried out over Ni promoted

Mo(W)S catalytic systems. Due to the stringent environmental legislations the unsupported

catalysts attracts much attention due to high activity (2-3 fold) than supported catalysts. In this work

we report synthesis of self-supported NiW catalysts, characterization and activity evaluation for the

HDS of 3-methyl thiophene (3MT). NiW catalysts were prepared by hydrothermal method.

Synthesized catalysts denoted as NiW-3, NiW-4, NiW-5, NiW-6 for which reagents used were HCl,

HCl+NaNO3, HNO3-24 h, HNO3-48 h, respectively. Catalytic activity tests were performed in

continuous flow micro reactor at 1 atm, 280-320 ˚C with ultra pure 3-methylthiophene. The TEM

analysis of WO3 samples exhibited flake like and irrgular structured particles for the samples derived

from HCl and HNO3, respectively. However, small particles were observed in the later case. The XRD

analysis of the WO3 samples indicated presence of monoclinic phase in all the samples. UV-Vis

spectroscopic results showed that presence of WO3 octaheral species for the samples prepared

using HCl and tetra hedral species observed for HNO3.

The HDS of 3-methylthiophene results showed that irrespective of the reaction temperature,

activity of the catalysts as follows: NiW-4 ≈ NiW-6 < NiW-3 < NiW-5. Highest reaction rate (341x108-

mol3MT.gCat1-.s1-) achieved for the NiW-5 catalyst compared to other syntheized catalysts. High

selectivity towards isoprene for all the catalysts indicating the HDS mechanism proceeds mainly

through direct desulfurization route. Therefore, this type of catalyst can be used for refractive

compounds like dibenzothiophene and real diesel.


PCNN - 16


Low temperature Atomic Layer Deposition of Ruthenium thin films using Ozone as a reactant

F. Solorio[*,1], S. Espinoza[1] ,E.G. Lizárraga-Medina[2], D. Domínguez[2], E. Murillo[2], H. Tiznado[2],

UABC; UNAM

Ruthenium thin films were grown by Atomic Layer Deposition (ALD) using

bis(ethylcyclopentadienyl)ruthenium as precursor and ozone or oxygen as reactant in a Beneq TFS-

200 model. The deposition process was optimized for both reactants, growing Ru films faster and

with shorter precursor doses. Particularly, the temperature was lowered from 350°C to 250 °C using

ozone as reactant. The electrical measurement, chemical composition and physical characterization

indicate different RuOx stoichiometry depending on the deposition parameters. Lower temperature

deposition increase the compatibility to work with different materials in nanolaminates.

Acknowledgments

The authors thank M.C. David Domínguez, Dr. Noemi Abundiz, M.C. Eloisa Aparicio and M.E. Jorge

Vázquez, for their support in characterization measurements. This work was supported by UNAM-

DGAPA-PAPIME PE100318, PE101317, UNAM-DGAPA-PAPIIT IN110018, IN112117, IA101018, and

FORDECyT 272894.


PCNN - 17


Ion exchange equilibrium curve between Mg(NO3)2 in solution and Zeolite type "Y" with ratio Si / Al = 15

Juan Manuel Medina López[*,1];Alma Luz A. Soltero[1]; Karina V. Chávez[1]; V. Soto.[1]

Laboratorio de Estado Sólido, Departamento de Química, Universidad de Guadalajara, Blvd. Marcelino García Barragán #1451, C.P 44430, Guadalajara, Jalisco,

Mexico.

Zeolites are highly crystalline minerals, which are formed by Silicon, Oxygen and Aluminum, which

make up the primary building units of the zeolite, these units are the tetrahedra of [SiO4]4- and

[AlO4]5- forming hydrogen bridges [1].

Zeolites have ion exchange properties due to the electrical charge imbalance of Aluminum

with respect to Silicon within the zeolitic structure itself. Other properties to be mentioned are, as

materials for removal, zeolitic supports containing metallic nanoparticles [2,3].

In the present work the ion exchange equilibrium curve in an aqueous solution of Mg(NO3)2

and the Zeolit "Y" ratio (Si / Al = 15) is studied, quantifying the amount of magnesium exchanged in

each concentration of the curve of balance. This curve is necessary for further developments in the

synthesis of supported magnesium clusters.

Acknowledgments

We would like to thank the Solid State Laboratory, the University of Guadalajara and the technician

support from Prof. Nestor Alfredo Trejo Perea

References

1. Lesley Smart. Elaine Moore. (2000), Química del estado sólido. Una introducción. Editorial

Addison Wesley iberoamericana. México

2. Anna Penkova et al. (2007), Effect of the Preparation Method on the State of Nickel Ions in BEA

Zeolites. A Study by Fourier Transform Infrared Spectroscopy of Adsorbed CO and NO, Temperature-

Programmed Reduction, and X-Ray Diffraction. J. Phys. Chem. C. 111, 8623-8631

3. H. van Beckum E.M Flanigen P.A. Jacobs and J.C. Jasen (2001), Studies in Surface Science and

Catalysis, Elsevier Science B.V. all rings reserved


PCNN - 18


Interaction of CO and NO with mono- and bimetallic Ag, Fe systems on mordenite: A FTIR study at room temperature

P. Sánchez-López[*, 1];Y. Kotolevich[1];S. Fuentes[1];G. Berlier[2];J. Antúnez-García[1];F. Chávez-Rivas[3];and V. Petranovskii[1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, Baja California, 22860 México;Università di Torino, Dipartimento

di Chimica and NIS Centre, Via P. Giuria 7, 10125, Torino, Italia;Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Ciudad de México, 07738

México

Monometallic Ag-Mordenite and Fe-Mordenite (AgMOR and FeMOR) and bimetallic AgFe-

Mordenite (AgFeMOR) systems prepared by ion exchange method were analyzed by FTIR coupled

to CO and NO probe molecules. Ion-exchange was performed in a sodium mordenite (NaMOR) with

а Si/Al ratio equal to 6.5, using silver nitrate and iron (II) sulfate aqueous solutions at 60°C. After

every ion exchange procedure, samples were filtered, washed and dried at 110 °C for 20 h.

The IR experiments were carried out on a Bruker IFS 66 FTIR instrument equipped with a cryogenic

MCT detector. The samples were in the form of thin self-supporting pellets (5-10 mg/cm²). The

samples were activated under a dynamical vacuum of pressure of 10-³ Torr at 400°C for 1 h, then

cooling to room temperature (RT) under vacuum (self-reduction activation). NO and CO were dosed

on the samples at room temperature after measuring the activated zeolite reference spectra.

Spectra were measured following a stepwise NO and CO pressures reduction.

We have found that FTIR spectra of adsorbed NO at RT display exclusively absorption bands of Fe

nitrosyl complexes (Fe3+(NO) and Fe2+(NO)n (n=1,2,3)) on AgFeMOR sample. While FTIR spectra of

adsorbed CO at RT display exclusively absorption bands of Ag carbonyls complexes (Ag1+(CO) and

Ag +(CO)) on AgFeMOR sample [1]. Thus, it was demonstrated that the interaction of NO is weaker

on Ag and Na cations in comparison with Fe cations, the FTIR spectra of AgFeMOR sample shows

mainly the NO adducts on iron species. On the contrary, the interaction of CO with iron species is

null at room temperature and shows only CO adducts of Ag species.

Authors acknowledge technical assistance of E. Smolentseva, E. Aparicio, J. Peralta and E. Flores.

This work was supported by UNAM-PAPIIT through grant IN107817. F. Chavez Rivas acknowledge

support from COFAA-IPN-Mexico.

[1] C. Lamberti, A. Zecchina, E. Groppo and S. Bordiga. Chem. Soc. Rev. 2010, 39, 4951–5001.


PCNN - 19


Hydrogen bond interactions induce of the formation 1-(2-Furoyl)-3-phenylthiourea multilayers on Au(111)

G. Navarro-Marín[1]; M. P. Hernández[1*];O. Estévez- Hernández[1]; M. H. Farías[2]; David Dominguez[2]; José Valenzuela B.[2];G. Alonso-Núñez[2]

Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, El Vedado, Plaza de la Revolución, La Habana 10400,

Cuba;Universidad Nacional Autónoma de México (UNAM), Centro de Nanociencias y Nanotecnología (CNyN). Km 107 Carretera Tijuana-Ensenada. Ensenada, Baja

California, Mexico

Aroyl-thiourea derivatives constitute attractive compounds for scientific community. Material

sciences, molecular recognition, agriculture and ion sensors are branches of knowledge where aroyl-

thiourea derivatives have emerged as promising candidates. However, molecular electronics studies

involving thiourea derivatives are scarce and they have used compounds with non-complex

chemical structures. The aim of the present work is to analyze the metal-molecule interface of some

derivatives with noble-metal XPS, STM and CV were the characterization techniques employed. The

selected molecules for the study were 1-(2Furoyl)-3-phenylthiourea (T1), 1-(2-Furoyl)-3-[(3-

trifluoromethylphenyl)]thiourea (T4) and 1-(2Furoyl)-3-(o-tolyl)thiourea(T6). Polycrystalline gold

substrates were annealed with butane flame to obtain monocrystalline gold terraces with

preferential orientation (111) and then were immersed in ethanolic solutions of compounds during

24 h. XPS O 1s, N 1s, S 2p and C 1s high resolution spectra were analyzed for the three derivatives.

In particular, binding energies of sulfur spectra are consistent with the adsorption of the molecules

on Au(111) and multilayer formation for T1 and T4, while T6 presents components associated with

polymeric sulfur phase. The presence of more than two components in O 1s and N 1s signals for T1

and T4 reveal the intermolecular (N-H··· S) and intramolecular (N-H··· O) hydrogen bond formation.

These interactions allow the packaging of thiourea derivatives to form multilayers. High resolution

STM images for T4 show thiourea multilayers on gold terraces and isolated molecules adsorbed on

the surface. STM images of T6 confirm the decomposition of the molecule, leaving only sulfur atoms

forming polymeric patterns. CV measurements shows the influence of the substituent groups in the

adsorption process.

Acknowledgments

We would like to thank the support of PREI-DGAPA for the invited professor to MPHS and

PNCBP223LH001-079.


PCNN - 20


Hydrogen bond interactions induce formation 1-(aroyl)-3-(substituted) thiourea multilayers on Au(111)

G. Navarro-Marín [1]; M. P. Hernández [1*]; O. Estévez- Hernández [1]; M. H. Farías [2]; David Díaz [2]; José Valenzuela B. [2]; G. Alonso-Núñez [2]

Instituto de Ciencia y Tecnología de Materiales (IMRE), Universidad de La Habana, Zapata y G, El Vedado, Plaza de la Revolución, La Habana 10400, Cuba;

Universidad Nacional Autónoma de México (UNAM), Centro de Nanociencias y Nanotecnología (CNyN). Km 107 Carretera Tijuana-Ensenada. Ensenada, Baja

California, Mexico.

Aroyl-thiourea derivatives constitute attractive compounds for scientific community. Material

sciences, molecular recognition, agriculture and ion sensors are branches of knowledge where aroyl-

thiourea derivatives have emerged as promising candidates. However, molecular electronics studies

involving thiourea derivatives are scarce and they have used compounds with non-complex

chemical structures. The aim of the present work is to analyze the metal-molecule interface of some

derivatives with noble-metal XPS, STM and CV were the characterization techniques employed. The

selected molecules for the study were 1-(2-Furoyl)-3-phenylthiourea (T1), 1-(2-Furoyl)-3-[3-

trifluoromethyl)phenyl]thiourea (T4) and 1-(2-Furoyl)-3-(o-tolyl)thiourea (T6). Polycrystalline gold

substrates were annealed with butane flame to obtain monocrystalline gold terraces with (111)

preferential orientation and then were immersed in ethanolic solutions of compounds during 24 h.

XPS O 1s, N 1s, S 2p and C 1s high resolution spectra were analyzed for the three derivatives. In

particular, Binding energies of sulfur spectra are consistent with the adsorption of the molecules on

Au(111) and multilayer formation for T1 and T4, while T6 presents components associated with

polymeric sulfur phase. The presence of more than two components in O 1s and N 1s signals for T1

and T4 reveal the intermolecular (N-H··· S) and intramolecular (N-H··· O) hydrogen bond formation.

These interactions allow the packaging of thiourea derivatives to form multilayers. High resolution

STM images for T4 show thiourea multilayers on gold terraces and isolated molecules adsorbed on

the surface. STM images of T6 confirm the decomposition of the molecule, leaving only sulfur atoms

forming polymeric patterns. CV measurements shows the influence of the substituent groups in the

adsorption process.

Acknowledgments

We would like to thank the support of PREI-DGAPA for the invited professor to MPHS and PNCB-

P223LH001-079.


PCNN - 21


GREEN NANOTECHNOLOGY: C-DOTS SYNTHETIZED FROM CITRUS FRUITS.

Marquillo Domínguez Mario [1]; García-Arellano Nancy [1]; Flores-López Lucía Z [1]; Rivero Espejel, Ignacio A. [1]; Espinoza Dueñas, Karla A. [1];*

INSTITUTO TECNOLÓGICO DE TIJUANA

Green nanotechnology is based on the main principles of green chemistry, green engineering,

nanomaterials and nanoproducts, avoided the use of toxic precursors. The reaction was carried out

at room temperature, without high energy requirements.

The production and process aspects of green nanotechnology impact; 1) the manufacture of

nanostructured materials in a friendly condition with the environment, and 2) the use of

nanostructures to modify established chemical processes, in such conditions, they can be benign for

the environment and the public health (1).

The carbon quantum dots can be used as in vivo image dyes, they work as probes for the distribution

of material within the cell, in order to evaluate cytotoxic processes. In recent years, there have been

great interest in applications of nanomaterials with specific optical properties for application in

biomedical areas and the optoelectronics industry.

In biomedicine the use of c-dots, has recently been demonstrated as dyes

of overexpressed proteins in cancer cells and other interesting proteins, imaging and photodynamic

therapy. Another application for Carbon-nanomaterials is in the design of electronic devices such as

LEDs, lasers, etc (2).

In this report, C-Dots synthesis is showed. The nanostructures were prepared with microwave

assistance technique from citrus fruits (lemon, tangerine). Materials were obtained in with good

yields, the nanostructured carbon materials were evaluated by fluorescence, ultraviolet, infrared

spectroscopic and FESEM techniques. The results show the manufacture of these materials in a time

not exceeding 5 minutes and with good fluorescence intensities.

Bibliography

1. Abha V., Megha S., Swati T., J. Pharm. Pharmaceutical Sci., 2017, 5(4), 60-66.

2. Mhetaer T., Yang X., Xue-Bo Y., Chin. J. Ana. Chem. 2017, 45(1), 139-150.


PCNN - 22


Fabrication of a TiO2/ZnO photocatalyst anchored on vertically aligned carbon nanotubes

O. A. Romo-Jimenez [1]; H. A. Borbón-Nuñez[2]; J. M. Romo-Herrera[3]; L. Arce [1]; G. Soto[3]; H. Tiznado[3]

Postgrado en Nanociencias, Centro de Investigación Científica y de Educación Superior de Ensenada; CONACyT-Centro de Nanociencias y Nanotecnología.

Universidad Nacional Autónoma de México; Centro de Nanociencias y Nanotecnología. Universidad Nacional Autónoma de México

Organic AZO dyes are among the most common persistent organic pollutants, directly emitted to

the environment by industries such as the textile, food and cosmetic industries. A great variety of

biological and physicochemical methods have been developed for the treatment of wastewater, of

which, photocatalysis represents an economic, ecological and effective method to destroy the

chromophore structures of the dyes. In this work we designed and manufactured a photocatalyst

device formed by vertically aligned N-MWCNTs on quartz coated with TiO2 and ZnO for the

elimination of the amaranth dye, using the techniques of CVD and ALD. First, an ultrasonic pyrolytic

spray system was constructed and characterized for the synthesis of N-MWCNTs. In the studies

carried out by transmission and scanning electron microscopy of the synthesized N-MWCNTs, it was

found that the morphological properties such as diameter and length can be controlled by the

synthesis parameters such as the gas flow and the temperature of growth, where, it was found that,

as the synthesis temperature increases, the diameter of the nanotubes increases. Also, it was

observed, by means of a study by XPS, that the nitrogen atoms embedded in the graphitic networks

were preferentially in pyrrolytic and substitutional form. Subsequently, the N-MWCNTs were coated

with a combination of TiO2 and ZnO, by the ALD technique. It was found that the nanotubes had a

uniform and conformal coating, however, areas of uncoated NMWCNTs were located, suggesting

that only the upper part of the nanotubes was coated. Photocatalytic tests of the manufactured

devices showed that the oxides separately had a better degradation of amaranth compared to the

combination of these. The device developed in this work can optimize one of the stages of the

process of remediation of water contaminated with amaranth, through a practical manipulation of

the photocatalytic material, because the photocatalyst is supported in N-MWCNTs aligned on

quartz.


PCNN - 23


Electrospun membranes of PMMA-ZnO for the dye degradation under exposure natural

Irela Santos Sauceda[a]; Osvaldo Campista Díaz[a]; M. Mónica Castillo Ortega[b]; Rafael Ramírez Bon [a]

Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro; Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora

Abstract

In this work is presented the preparation and characterization of poly (metyl methacrylate) (PMMA)

membranes with ZnO by electrospinning. Their properties were analyzed by scanning electronic

microscopic (SEM-EDS), Fourier-Transform Infrared spectroscopy (FTIR) and X-ray diffraction (DRX).

The potential of fibrous material for the degradation of dye aqueous solutions under dark and

sunlight irradiation was studied using UV-Vis absorption and photoluminescence spectroscopies.

The images of SEM shows a morphology fibrous with particles, the mapping by EDS presents the

distribution of the chemical elements such as Zn, O by all the PMMA fibrous material. With the EDX,

the presence of semiconductor is confirmed. The FTIR doesn’t show a possible interaction between

the components. On the other hand, the results revealed that the dye molecule discoloration with

PMMA-ZnO fibers was better in the sunlight irradiation that under the dark conditions. The

absorption band maxima of methylene blue decreased with the time in absence and presence of

polymer under solar natural exposition. However, in the case for the rodhamine, the absorption

band maxima no decreased significantly with the time in absence of composite, while in presence

of fibrous material, this band decreased with the time under solar natural exposition. This work

provides a method simple for the degradation of wastewater effluents.

Keywords: electrospinning; poly (methyl methacrylate); dyes; sunlight


PCNN - 24


Effect of the reduction temperature on the final size of the nickel clusters synthesized in the "Y" type zeolite, with Si / Al = 15, ratio.

Saul De La Torre[*,1]; Pedro Velazquez-Ponce[1]; V. Soto[1]; Karina V. Chávez[1]

Laboratorio de estado sólido, Departamento de Química, Universidad de Guadalajara, Blv. Marcelino García Barragán #1451, C.P44430, Guadalajara, Jal., México

The zeolites are aluminosilicatos minerals that when found naturally, are formed by a cycle of

accumulation and compaction. Different synthetic zeolitic materials have also been developed for

different uses and applications.

Zeolites represent one of the most important topics in the development of materials. They have

been used, from simple ways as filtering material or ion exchangers and molecular separators. At

present they are used as heterogeneous catalysts, since one of their qualities is that they have a

high selectivity. [1]

In this work, we intend to find the relationship between the final size of the nickel nanoparticles

embedded in "Y" type zeolite (Si / Al = 15), versus the temperature used in the reduction process.

This allows us to be at the vanguard in the synthesis of more efficient and low-cost materials, in

addition to that we influence the surplus of the exploitation of nickel. [2,3]

This work lays the basis for the subsequent synthesis of nanostructures of gallium nitride.

Aknowledgements:

I thank the Solid State Laboratory, the University of Guadalajara and the intellectual and personal

support of the Mtra. Karina Viridiana Chávez and Dr. Victor Soto. Those who have tirelessly guided

me and directed me to develop in my research work.

References:

[1] Lesley Smart/Elaine Moore. 1982. Quimica del estado solido.-2da edicion. EDIT: Madison

Wesley.

[2] Galo Soler Illia (2009). Nanotecnologia. El desafio del siglo XXl. Pag 12

[3] Autor Laura Superneau Director Phaedra Troy http://www.bnamericas.com/es/intelligence-

series/mineriaymetales/niquel-en-america-latina-es-tiempo-de-apurar-el-paso


PCNN - 25


Effect of the ion exchange cycles on the final size of the Mg nanoparticles obtained in "Y" Zeolite with Si / Al ratio = 15

Luis Enrique Valdez Cortes [*,1]; Jazmín Soltero [1]; V. Soto [1]; Karina V. Chávez. [1]

Laboratorio de Estado Sólido, Departamento de Química, Universidad de Guadalajara, Blvd. Marcelino García Barragán #1451,C.P 44430, Guadalajara, Jalisco,

México.

The zeolites are microporous aluminosilicates widely used in the chemical industry. The Si-Al-O

structure of the zeolite is rigid and negatively charged. In order to neutralize said negative charge it

is necessary the presence of a cation (Na+, H+, NH4+ ... etc) in the aluminum occupied sites, which

are easily replaceable by other cations [1,2,3]. This is the basis of the cation exchange process.

In this work we propose the exchange with Magnesium cations followed by the reduction process

by means of hydrogen flow. This process is carried out in a cyclic way with the intention of increasing

the final size of the Magnesium nanoparticles formed.

A direct correlation is offered between the final diameter of the magnesium nanoparticles

synthesized according to the number of ion exchange cycles used for their synthesis.

Acknowledgments

We would like to thank the Solid State Laboratory, the University of Guadalajara and the technician

support from Prof. Nestor Alfredo Trejo Perea

References:

1. Maeva Borel, Mathias Dodin, T. Jean Daou, Nicolas Bats, Bogdan Harbuzaru and Joël Patarin. SDA-

Free Hydrothermal Synthesis of High-Silica Ultra-nanosized Zeolite Y. (2017)

2. Lesley Smart. Elaine Moore. Solid state chemistry. An introduction. Addison Wesley

iberoamericana. Mexico. (2000)

3. Rodney P. Townsed and Eric N. Coker. Ion exchange in zeolites Chapter 11.(2001).


PCNN - 26


Effect of metal oxide and carbon supports on catalytic performance of bimetallic nanoparticles in lignocellulose-derived levulinic acid hydrogenation

Irina Simakova [*, 1]; Yuliya Demidova [1]; Sergey Prikhod’ko [1]; Mikhail Simonov [1]; Nandini Devi [2]; Paresh Dhepe [2]; Vijay Bokade [2]; Andrey Simakov [3]

Boreskov Institute of Catalysis, pr. Ak. Lavrentieva, 5, Novosibirsk, 630090, Russia; CSIR-National Chemical Laboratory, Pune, 411008, India; Centro de Nanociencias

y Nanotecnología de la Universidad Nacional Autónoma de México, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, México

Levulinic acid (LA) prepared from lignocellulose is one of the most promising platform molecules

widely applied in the fields of fuel additives, plasticizers, chemical solvents, spices and

pharmaceutical synthesis [1]. Crude LA, formed by acid-catalyzed hydrolysis of cellulose occurring

via conversion of the intermediate product glucose to 5-hydroxymethylfurfural, can be transformed

into γ-valerolactone (GVL). Other compounds such as 2-methyltetrahydrofuran (2-MTHF), alkyl

valerates, 1,4-pentanediol (1,4-PDO) and pyrrolidinones can be also formed affecting LA

hydrogenation selectivity. 2-MTHF along with GVL is of high interest as a valuable component of

biofuels, a "green solvent" and a promising platform molecule in organic synthesis.

In the present work LA hydrogenation was studied over bimetallic catalysts - Pt and Ir modified with

rhenium supported on alumina and titania as well as on carbon to improve catalyst stability.

LA (98%, Acros Organics, Belgium) (25 mL, 0.035 М) was hydrogenated at 180oC and 25 bar of H2.

Catalysts were prepared by impregnation with metal chloride precursors followed by hydrogenation

at TPR conditions and characterized by TEM, XRD, XPS, TPR. Reaction components were analyzed by

GLC using BP20 capillary column (60 m/0.25 mm/0.25 μm) (Chromos GC-1000).

It was found that contrary to other catalysts IrRe/Al2O3 selectively catalyzed LA hydrogenation into

GVL with further conversion into 2-MTHF as the major product containing 1- and 2-pentanols as

impurities. The reaction network revealed LA conversion over IrRe/Al2O3 is in line with the literature

data for nickel-copper catalysts [2], however, the yield of 2-MTHF (46% after 1.5 h) was higher than

that over Ni-Cu/Al2O3 (56% after 5 h) at a lower temperature (180oC vs 250oC).

Acknowledgments


References

1. F.D. Pileidis, M.-M. Titirici, ChemSusChem, 2016, 9, 562–582.

2. I. Obregon, I. Gandarias et al., ChemSusChem, 2015, 8, 3483–34.


PCNN - 27


Effect of iron ions on formation of silver species in mordenite

P. Sánchez-López[*, 1];V. Petranovskii[1];S. Fuentes[1];D. Bogdanov[2];E. A. Krylova[2];M.G. Shelyapina[2];Yu. Zhukov[2];I. Rodriguez-Iznaga[3];J. Gurgul[4];K. Łątka[5]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, Baja California, C.P. 22860 México;Saint Petersburg State

University, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia;Instituto de Ciencias y Tecnología de Materiales (IMRE), Universidad de La Habana. Zapata y

G, s/n La Habana 10400, Cuba;Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland;M.

Smoluchowski, Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland

Silver-based materials have acquired great interest due to their potential effectiveness in various

catalytic processes in chemical industry, such as in fuel production, fine synthesis, medicine and

cosmetics. A good supported catalyst must have a good and controlled dispersion of the active

phase on the surface of support.

Monovalent Ag+ cations are stable in water solution, so ion exchange can be easy done in zeolites.

Likewise, the reversible oxidation-reduction of silver provides a useful system to study the

mechanism of ensembles formation for spatially well-defined metal clusters. Ag-catalysts modified

with transition metals are very interesting due to the influence of promoter element on the process

of formation of clusters and nanoparticles on zeolites. It opens the way to the ultimate goal of

modern cluster science, that is, to develop methods of synthesis of nano-objects with well-

controlled properties in the nanoscale range. Thus, the understanding of physicochemical

properties and active phases in these systems will allow a better design of catalysts and other

modern materials.

Zeolites with regular pores of controlled diameter can serve as a matrix for the synthesis of such

clusters. Recent studies have shown that introduction of iron ions in the zeolite-silver system has a

dramatic impact on the mechanisms of silver cluster formation in zeolite matrix. Here we present

results of studies for structural (XRD), elemental (XPS, ICP), morphological (SEM, TEM), thermal

analysis, Mossbauer and EPR of Ag-Fe/mordenite systems synthesized from sodium mordenite by

ion exchange from silver nitrate and/or iron (II) perchlorate solutions.

The work was partly supported by SENER-CONACYT (project 117373), RFBR and CITMA in

accordance with research Project No. 18-53-34004.


PCNN - 29


Defective graphene nanosheets for nucleobases adsorption and detection: A theoretical description.

Alan Miralrio[*,1]; Ximena Martinez-Coronel [1]; Roberto Carrion-Ramirez [1]; Miguel Castro [1]

Departamento de Física y Química Teórica, DEPg. Facultad de Química, UNAM, Del. Coyoacán, Ciudad de México

In recent years, several graphene-based nanodevices have been developed for DNA sequencing.ǂ

In this work, the electronic structure and properties of the nucleobases: adenine, thymine, guanine,

cytosine and uracil, involved in the DNA and RNA formation, interacting with defective graphene

nanosheets, is theoretically described within dispersion-corrected density functional theory. The

adsorption of nucleobases on the surface of several defective graphene nanosheet models is

analyzed. Graphene nanosheets are chemically activated by means of intrinsic (single vacancies and

Stone-Wales defects) and extrinsic (boron and nitrogen doping) point defects. Differences produced

by adsorbtion of several tautomers of nucleobases in the defective graphene nanosheets, relative

to pristine graphene, are characterized, in order to obtain novel manners to differentiate among

them. Analyses are done in terms of adsorption energies, ionization energies, electron affinities,

frontier molecular orbitals, charge distributions, IR vibrational spectra and electrostatic potentials.

Results are compared with those obtained for isolated defective graphene and nucleobases in the

gas phase experimentally characterized.

ǂHeerema, S. J., &Dekker, C. (2016). Graphene nanodevices for DNA sequencing.

Naturenanotechnology, 11(2), 127.

Corresponding Author: [email protected]


PCNN - 30


Cu-Ag bimetallic systems supported on clinoptilolite and mordenite: a study of NO adsorption by Temperature Programmed Desorption, and NO selective catalytic

reduction

I. Rodríguez-Iznaga [1]; V. Petranovskii [*,2]; S. Fuentes-Moyado [2]; F. Castillón-Barraza [2]; M.G. Shelyapina [3]

Instituto de Ciencias y Tecnología de Materiales (IMRE) – Universidad de La Habana. Zapata y G, s/n La Habana 10400, Cuba; Centro de Nanociencias y

Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, B.C. 22860, México; Saint-Petersburg State University, 7/9 Universitetskaya nab., St.

Petersburg 199034, Russia

This work presents studies on NO adsorption/desorption by Temperature Programmed Desorption

(NO-TPD), and Selective Catalytic Reduction of NO with C3H6/CO in the presence of O2, which

occurs on Cu2+-Ag+ systems supported on synthetic mordenite (MOR) and natural clinoptilolite (CLI)

through ion exchange processes. It was shown that sites with the highest catalytic activity in NO

reduction are associated with Cu atoms. Bimetallic CuAg catalysts showed higher activity than

monometallic Cu samples. Catalysts supported on MOR have higher activity than their homologs

supported on CLI. The highest activity correspond to CuAgMOR, with NO conversion of 77% at

390oC, despite the lower Cu content. For bimetallic catalysts supported on CLI, the highest achieved

NO conversion was of 30% at 460oC. For NO-TPD, two adsorption regions were found on the

CuAgMOR sample, one centered at 70oC and the other at 400oC. Bimetallic catalysts supported on

CLI showed three adsorption regions centered at 90oC, 245oC and 400oC. Adsorptions at low

temperatures were associated with nitrogen oxides and nitrosyl groups, while at 400oC with

nitrite/nitrate complexes formed during oxidation NO oxidation with O2 [1]. The lower activity of

catalysts supported on CLI may be associated with NO adsorption at sites not active for NO

reduction. This may be due to the adsorption observed at 245oC, which is not represented in the

bimetallic catalyst supported on the MOR. The larger diameter of the MOR channels with respect to

CLI should favor the oxocations formation and consequently the catalytic activity.

Acknowledgements

Thanks are given to E. Aparicio, I. Gradilla, J. Peralta, J. Gonzalez and E. Flores for assistance. The

research was supported by grants UNAM-PAPIIT-IN107817, SENER-CONACYT-Hydrocarbons No

117373 and 18-53-34004 Russia-Cuba (RFBR-CITMA).

References

1. R. Ramírez-Garza, I. Rodríguez-Iznaga, A. Simakov, M. Farías, F. Castillón, Mater. Res. Bull. 97, 369

– 368 (2018)


PCNN - 31


Cooperative effect of IrRe for selective hydrodeoxygenation of lignocellulose derived oxygenates: levulinic acid and crotone aldehyde

Yuliya Demidova [*1]; Irina Simakova [1]; Alina Yaroslavtseva [2]; Nandini Devi [3]; Paresh Dhepe [3]; Vijay Bokade [3]; Andrey Simakov [4]

Boreskov Institute of Catalysis, pr. Ak. Lavrentieva, 5, Novosibirsk, 630090, Russia;Novosibirsk State Technical University, 630073, pr. K. Marksa, 20, Novosibirsk,

630090, Russia;CSIR-National Chemical Laboratory, Pune, 411008, India ; Centro de Nanociencias y Nanotecnología de la Universidad Nacional Autónoma de

México, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, México

Recently a significant development has been made in the realm of bimetallic catalysts [1,2].

Compared to monometallic counterparts, the bimetallic systems often exhibit higher efficiency

because of the synergism between two metal centers. One of the most attractive approaches to

design such bimetallic systems is to link two metal centers with proven efficiencies for a particular

catalytic system with the help of some functional ligands that has been used typically to design

bimetallic catalysts comprised of noble metals. In this work this approach was extended to systems

comprising noble Ir and a non-noble Re to develop effective catalysts for transformation of

lignocellulose derived levulinic acid (LA) into valuable chemicals and biofuels, e.g. g-valerolactone

(GVL).

LA and crotonaldehyde (CA) (98%, Acros Organics, Belgium) were hydrogenated at 180oC, 25 bar of

H2 and 150oC, 1 bar H2, respectively. The catalysts were prepared by impregnation with metal

chloride precursors followed by reduction at TPR conditions and characterized by TEM, XRD, XPS,

TPR. Reaction components were analyzed by GLC using BP20 capillary column (60 m/0.25 mm/0.25

μm) (Chromos GC-1000).

The properties of IrRe catalysts were tuned by variation of Ir/Re ratio, metal loading, sequence of

metal introduction, reduction temperature and amount of Cl residue and evaluated first in selective

hydrogenation of C=C or C=O bonds in crotonaldehyde. The insight on catalytic performance

obtained for unsaturated aldehyde hydrogenation was applied for development of selective

synthesis of GVL from LA.

Acknowledgments


References

1. M. Tamura, K. Tokonami, Y. Nakagawa, K. Tomishige, ACS Sustainable Chem. Eng., 2017, 5,

3685−3697.

2. Q. Yu, X. Zhang, B. Li, J. Lu, G. Hu, A. Jia, C. Luo, Q. Hong, Y. Song, M Luo, J. Mol. Catal. A: Chem.,

2014, 392, 89–96.


PCNN - 32


Characterization of Copper Sites in Mordenites by Low-Temperature FTIR Spectra of Adsorbed CO

A. Tsyganenko[*,1]; O. Pestsov[1]; R. Belykh[1]; R. Novikov[1]; M. Shelyapina[1]; V. Petranovski[2]

Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, Russia 199034; Centro de Nanociencias y Nanotecnologıa de la, Universidad Nacional

Autonoma de Mexico, 22860 Ensenada, Baja California, Mexico

Low-temperature infrared (IR) spectroscopy of adsorbed molecules is widely used to identify surface

species. Copper-exchanged zeolites are highly promising catalysts for removal of nitrogen oxides

(de-NOx) and other processes. To improve their properties it is necessary to understand the state

of copper sites. The content and specific forms of copper species are highly affected by preparation

method. Recently it has been shown that microwave assisted copper ion-exchange treatment of

sodium mordenite leads to diversification of copper species stabilized inside the mordenite pores

[1]. By means of ESR [1] and FTIR spectroscopy [2] one can detect Cu2+, Cu+ and [Cu–O–Cu]2+

species.

Method of isotopic dilution with 12CO-13CO (30%-70%) mixtures enables us to distinguish bands of

single adsorbed molecules from those of binary CO species at the same surface Cu sites. After CO

addition to a sample of Cu mordenite prepared by microwave treatment and evacuated at 450°C

we can see three bands at 2190, 2161 and 2143 cm-1 for 12CO, while adsorption of 12CO-13CO

mixture leads to similar bands, each shifted by approximately 50 cm-1 to lower wavenumbers, and

only one band in the region of 12CO at 2165 cm-1. After evacuation for 10 minutes two bands are

obtained for 12CO adsorbed separately, while for the isotopic mixture two downwards shifted

bands with a similar contour and only one band of 12CO at 2168 cm-1, not coinciding with those of

pure isotope. Pumping at 200°C leaves one band of 12CO at 2159 cm-1, for the isotopic mixture the

same band is accompanied by that of 13CO at 2110 cm-1. The difference between the band positions

of 12CO adsorbed alone from those of the same isotope admixed in 13CO testifies for the resonant

dipole-dipole interactions as a reason of complex spectra of adsorbed CO.

1. M.G. Shelyapina et al. // J Therm Anal Calorim, 134, 71 (2018)

2. K. Hadjiivanov et al. // J. Catalysis, 191, 480 (2000)

The work was supported by RFBR and CITMA, grant No.18-53-34004


PCNN - 33


Al2O3-TiO2-W Catalysts; Effect of Acid-Basic Sites Ratio on the Catalytic Activity for 5-HMF

Claudia G. Espinosa-González [1*]; Gerardo E. Córdova-Pérez [2]; José G. Torres-Torres [2]; Filiberto Ortíz-Chi [1]; Srinivas Godavarthi [1]; Adib A. Silahua-Pavón [2; Armando Izquierdo-Colorado [3]; Patrick Da

Costa [3]

Cátedras CONACYT-Universidad Juárez Autónoma de Tabasco; Centro de Investigación en Ciencia y Tecnología Aplicada de Tabasco CICTAT, Universidad Juárez

Autónoma de Tabasco; Sorbonne Universite, CNRS Institut Jean Le Rond d’Alembert

Nanocatalysts of Al2O3-TiO2-W with variation of 5-20 w% in Tungsten (W) composition were

prepared using an innocuous and easy sol-gel method, at room temperature, and under acid and

basic pH conditions. The morphological and composition of the materials were studied by Scanning

Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS), respectively, Density of

acid and basic sites by NH3 and CO2 temperature programmed desorption (TPD) technique

respectively, and physicochemical properties by N2 physisorption studies, X-ray diffraction (XRD),

and UV-Vis spectroscopy. The catalytic application of Al2O3-TiO2-W was examined for the

conversion of glucose to produce 5-hydroxymethylfurfural (5-HMF) and the best yield of 5-HMF was

almost 70% with the catalyst of 5 w% W load. This yield level was achieved when the catalyst with

acid-basic sites molar ratio of 2.35 was probed.


PCNN - 34


Physicochemical properties of Cu- and Pd- oxides over mixed γ–χ–Al2O3 for methanol dehydration

M. A. Armenta [1]; V. M. Maytorena [2]; F. Aguilera [3]; R. Valdez [3]; A. Olivas [3*]

PCeIM, Centro de Nanociencias y Nanotecnología–UNAM; Departamento de Ingeniería Química y Metalurgia-UNISON; CNyN–UNAM

In this work, we deposited CuO, PdO, and CuO–PdO on γ–χ–Al2O3 by a facile impregnation method.

To date, PdO supported in γ–χ–Al2O3 is used for the first time in the methanol dehydration reaction.

This reaction (2CH3OH → CH3OCH3 + H2O) is one of the most appropriate catalytic reactions to

produce dimethyl ether (DME). A meticulous study of the effect of temperature on the catalytic

properties of the catalytic systems is carried out, as well as the effect of the nanoparticle size, the

support and its relationship with the active phase. In addition, we studied the stability and

recyclability of the catalysts after the methanol dehydration. We did a thermodynamic analysis and

obtained the values of enthalpy ΔH°T, entropy ΔS°T, Gibbs free energy ΔG°T and equilibrium

constant K°T associated with the dehydration of methanol. Also, we evaluate the activation energies

values (Ea) for the methanol dehydration using the catalyst that performed the highest catalytic

activity, CuO–PdO/γ–χ–Al2O3, compared with the material with the lowest catalytic activity, γ–χ–

Al2O3.


PCNN - 35


FTIR spectroscopy for the studies of catalysts and catalytic reaction mechanisms

Alexey Tsyganenko [1]

V.A.Fock Institute of Physics, St.Petersburg State University, St.Petersburg, 198504, Russia

The paper deals with the advances in the studies of active sites, the structure of intermediates of

the reactions catalyzed by oxides and zeolites using FTIR spectroscopy at variable temperatures. At

low temperatures one can use molecules that do not adsorb at 300 K to characterize surface acid or

basic sites. Simultaneous measurements of spectra, pressure and temperature enables one to study

thermodynamics of surface processes. To establish the mechanism of catalytic reactions we can

follow spectra evolution with temperature, while the structure of intermediates can be clarified

using isotopic substitution.

Some adsorption products cannot be stabilized at low temperatures, but arise as a result of thermal

excitation. So, CO, besides the usual C-bonded structure, forms with cations energetically less

favorable O-bonded species, which can act as activated states in catalytic reactions. As a specific

kind of isomerism one can consider a case when the two isomers differ in their isotopic composition

as it was found for isotopically mixed dicarbonyl or dinitrosyl complexes or products of HD

dissociation.

The strength of surface sites can be affected by lateral interactions between the adsorbed species,

which modify the catalytic properties of solids and shift the bands of test molecules distorting the

data on surface acidity. Co-adsorption of acidic and basic molecules leads to mutual enhancement

of adsorption. Besides the effects of induced acidity or basicity, the effect of superacidity of oxides

doped with sulfate ions or higher acidity of cations in zeolites than on oxides of the same elements

can be explained.

For quantitative spectral analysis of surface sites the knowledge of absorption coefficients of test

molecules is needed. The theory predicts a correlation between the frequency shifts on adsorption

and the absorption coefficients, in a fair agreement with the data on adsorbed CO.

Acknowledgement. The work was supported by RFBR, Grant 17-03-01372


PCNN - 36


Activation of MoS2 Monolayers by Substitutional Copper and Silver Atoms Embedded in Sulfur Vacancies: A Theoretical Study.

Alan Miralrio [*,1]; Eduardo Rangel [2]; Miguel Castro [1]

Departamento de Física y Química Teórica, DEPg. Facultad de Química, UNAM, Del. Coyoacán, Ciudad de México 04510, Mexico; Energetic Systems and Advance

Materials, Escuela Superior de Apan, Universidad Autónoma del Estado de Hidalgo, Carretera Apan-Calpulalpan Km. 8, Col. Chimalpa, Apan, ZIP 43920, Hidalgo,

Mexico

Defective molybdenum disulfide monolayers, with up to three copper and silver atoms substituting

sulfur atoms, were studied at a dispersion-corrected DFT level. By the first time, changes produced

on electronic properties, reactivity, charge distribution and electrostatic potential by trapping these

atoms are widely discussed. Embedded species are expected to remain stable and fixed, since large

and favorable metal cluster-vacancy defective monolayer binding energies are obtained, higher

than – 2.60 eV in all cases. Several defect states are induced in the forbidden region, being the band

gap reduced as more substitutional atoms are added. These states mostly come from molybdenum

d and p orbitals from embedded metals. Also, defects reduce the gap up to 0.10 and 0.35 eV, for

copper and silver trimers, respectively. Substitutional single atoms and dimers donate charge to

molybdenum atoms in the middle layer, whereas trimers tend to accumulate it. However, charge

transfer is marginal and the most important rearrangements are produced in atoms neighboring

defects. Regions with lower electrostatic potential are produced around the defects. Condensed

Fukui indices reveal that systems with defects enhanced the chemical reactivity, towards

nucleophilic and nucleophilic attacks, in regions around the embedded species. In contrast to the

chemically inert pristine MoS2 monolayer, changes on electronic, energetic properties and reactivity

of all defective systems indicate that are promising materials for catalytic purposes and to adsorb

other molecules

Corresponding Author: [email protected]


PCNN - 37


Ab initio study and growth of superconducting tantalum nitride thin films by pulsed laser deposition

Cedillo, M. I. [1*]; Díaz, J. A. [1]; De la Cruz, W. [1]; Guerrero, J. [1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México

Since its discovery at 1911 by Kamerlingh Onnes, the superconductivity has been a promising

property of specific materials that is important for scientists and engineers. Particularly, the

superconducting materials have applications in lossless energy power supply, transport levitation

and development of nanometric electronic devices. In this latter issue, efficient fabrication of

materials with a low superconductive energy gap and an intermediate transition temperature (Tc ),

results essential for the development and enhancement of superconductive electronic devices in

the GHz range. TaN thin films have previously showed superconductive transition temperatures of

up to 10.4 K with a superconductive energy gap lower than NbN, the most commonly used material

for single photon detectors in the GHz range. The Tc of tantalum nitride depends strongly of the

crystallinity and stoichiometry of the thin films. In the present work, superconductive thin films of

tantalum nitride were grown by using the laser ablation technique with a Nd-YAG laser on a Ta target

(99.999%) varying the N2 (99.999%) partial pressure in the chamber as well as substrate

temperature. X-Ray Diffraction Spectroscopy (Panalitycal X’pert Pro MRD system) and X-Ray

Photoelectron Spectroscopy (XPS), with a X-ray monochromatic source and semispherical analyzer,

from SPECS were obtained in order to study the crystallography and stoichiometry respectively. The

R vs T curve of the films were obtained by using four probe method. Finally, we report an ab initio

study of an fcc unit cell of tantalum nitride using Quantum ESPRESSO software. We calculated the

states density with the purpose of correlating them with our experimental results obtained from

XPS close to the Fermi energy.

Acknowledgments

We would like to thank the technical support of D. Domínguez, E. Aparicio, I. Gradilla and E. Murillo.

This work was supported by CONACyT-FORDECyT project 272894


PCNN - 38


Colloidal Ru nanoparticles: preparation, structural and catalytic properties in synthesis of biofuel components from lignocellulose-derived oxygenates

Irina Simakova [*, 1]; Andrey Simakov [2]; Yuliya Demidova [1]; Sergey Prikhod’ko [1]; Nandini Devi [3]; Paresh Dhepe [3]; Vijay Bokade [3]

Boreskov Institute of Catalysis, pr. Ak. Lavrentieva, 5, Novosibirsk, 630090, Russia; Centro de Nanociencias y Nanotecnología de la Universidad Nacional Autónoma

de México, Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California, México; CSIR-National Chemical Laboratory, Pune, 411008, India

Recently, superior catalytic efficiency of well dispersed Ru on activated carbon catalysts was

demonstrated in hydrogenation of lignocellulose-derived levulinic acid (LA) into fuel components y-

valerolactone (GVL) and 2-methyltetrahydrofuran (2-MTHF) under mild reaction conditions. In our

earlier studies size-controlled Ru NPs immobilized on carbon support were successfully synthesized

[1] demonstrating high activity in hydrogenation of galactose and arabinose [2, 3].

In this work size-controlled Ru/C catalysts were developed to elucidate the effect of their dispersion

and microtexture on catalytic performance in selective LA hydrogenation. A series of Ru on carbon

catalysts was prepared by impregnation and colloidal methods. PVP-protected colloidal Ru NPs were

first synthesized by the polyol method using ethylene glycol followed by deposition on carbon

support. The leftover of PVP in colloidal Ru/C catalysts was removed by solvothermal (water or

acetic acid aqueous solutions) or thermal treatments using different gases such as air (180⁰C), H2

(400⁰C) and N2 (500⁰C). All catalysts were tested in LA (Acros Organics, Belgium) hydrogenation at

180oC and 25 bar. It was found that activity of Ru colloidal catalysts was lower in comparison with

prepared by impregnation, however, catalyst pretreatment by thermal methods significantly

improved catalytic activity. The optimal ruthenium NPs size was shown to be 2-3 nm. GVL yield

varied in the range 84-90% depending on the catalyst synthesis method. The catalysts were studied

by TEM, XRD, and N2 physisorption before and after the reaction to elucidate changes upon the

reaction medium.

Acknowledgments


References

1. I.L. Simakova et al. Int. J. Nanotech. 2016, 13, 14-25.

2. I.L. Simakova et. al. Catal. Sci. Technol., 2016, 6, 8490–8504.

3. I.L. Simakova et al. Catal. Lett., 2016, 146, 1291–1299.


PCNN - 39


Synthesis of g-C3N4/metal oxide composites and their photocatalytic Applications

Fuentez-Torres M. O. [1]; Alcudia-Ramos M. A. [1]; Ortiz-Chi F. [2]; Espinosa-González C. G. [2]; Aleman M. [3]; Kesarla M. K. [4]; Collins Martínez V. H. [5]; García Zaleta D. S. [6]; Torres-Torres J. G. [1];

Godavarthi S.[2*]

Universidad Juárez Autónoma de Tabasco, CICTAT, C.P. 86690 Cunduacán, Tabasco, México; Cátedras Conacyt – Universidad Juárez Autónoma de Tabasco, CICTAT,

C.P. 86690 Cunduacán, Tabasco, México; Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional, Mexico City, México; Department of

Chemistry, Madanapalle Institute of Technology & Science, Angallu (V), Madanapalle, 517325, Andhra Pradesh, India; Departamento de Ingeniería y Química de

Materiales, CIMAV, Miguel de Cervantes 120, Chihuahua, Chih., 31136, México; Universidad Juárez Autónoma de Tabasco, División Académica Multidisciplinaria de

Jalpa de Méndez, Carr., Jalpa de Méndez, Tabasco, 86205, México

During the last decades, research has been carried out on photocatalytic materials that can be used

for the degradation of pollutants as well as for the generation of renewable energies that have a

high positive impact on the environment. In this work we focused on the preparation of different

compounds such as: g-C3N4-ZnO, g-C3N4-CeO2-N and g-C3N4-TiO2. The first two compounds were

prepared by dispersion method and the latter was developed using hydrothermal method. The

physicochemical properties of the synthesized compounds were analyzed using various

characterization techniques such as, Nitrogen Physisorption (BET), XRD, UV-vis, XPS, HRTEM, and

correlated with their photocatalytic activity. The photocatalytic activity of g-C3N4-ZnO, g-C3N4-

CeO2-N was studied through Diuron degradation under simulating sunlight using a "Suntest CPS +"

benchtop equipment equipped with cooling air and with a Xenon lamp that reaches up to 1500 W

of power. For example, g-C3N4-CeO2-N compound showed a photocatalytic efficiency in a

degradation of the herbicide Diuron of up to 46% in 2 hours. The compound g-C3N4-TiO2 was

evaluated in the production of hydrogen through water splitting and showed a maximum of 1180

μmol / h during 8 hours of reaction using visible light. This work will discuss each of the before

mentioned g-C3N4/metal oxide composite properties and their photocatalytic efficiencies in detail.


PCNN - 40


Physicochemical properties of the luminescent material Li3Ba2La3(MoO4)8:(Eu3+,Tb3+) fabricated by combustion synthesis

Kora Lu Rojas Baldivia[*,1,2]; David Cervantes Vásquez[3]; Gustavo A. Hirata[2]

Posgrado en Nanociencias-Centro de Investigación Científica y de Educación Superior de Ensenada; Centro de Nanociencias y Nanotecnología, Universidad Nacional

Autónoma de México; Facultad de Ingeniería, Arquitectura y Diseño, Universidad Autónoma de Baja California

The primary goal of this work is to produce a luminescent material with red emission for applications

in white light lamps based on LED's. In particular, a material with wavelength at = 617 nm excited

under long wavelength UV light and based on Eu3+, Tb3+- activated molybdates Li3Ba2(La1-x-

yEuxTby)(MoO4)8 with 0≤x≤1 and 0≤y≤1. A series of powder samples were synthesized by the

combustion method and post-annealed at 800°C in air. The phase formation of the samples was

investigated by X-ray diffraction which revealed the monoclinic C2/c (15) space group with Z=2, in

agreement with the JCPDS 01-077-0830 database reports. A detailed characterization by Scanning

Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) showed a similar

morphology in all samples: rather large (1-7 µm) agglomerate particles with irregular shape and

surrounded by smaller (~50 nm) particles. Cathodoluminescence measurements indicated that the

composition is optimal for Eu3+:Tb3+ doping ratios of 80:0, 90:0 and 20:80, while the samples with

80:0 and 60:40 doping ratios showed the highest intensity in a detailed photoluminescence analysis.

The luminescent material per the composition Li3Ba2La3(MoO4)8:(Eu3+, Tb3+) is a promising

candidate for its application as a red emitting component in artificial lighting systems based on solid-

state devices, in particular, light-emitting diodes.

Acknowledgments

We acknowledge to DGAPA-UNAM (Grant No. IN-111017) and CONACyT (Grant No. 284548), as well

as Eloisa Aparicio, Francisco Ruíz, Jaime Mendoza, Israel Gradilla from CNyN and Dra. Eunice Vargas

from UABC, for their technical support.

References

1. Katelnikovas, A. et al. “Synthesis and optical properties of Li3Ba2La3(MoO4)8:Eu3+ powders

and ceramics for pcLEDs”, Journal of Materials Chemistry, 22(41), 22126–22134, (2012).

2. Van De Haar, M. A. et al. “Increasing the effective absorption of Eu3+-doped luminescent

materials towards practical light emitting diodes for illumination application


PCNN - 41


CARBON-DOPED NANOSTRUCTURES IN FUEL CELLS

Valenzuela Muñiz A. M.; Rodrigo Fernandez, L.; Ugarte Y.; Zeferino Gonzalez I.; Alonso Nuñez G.; Verde Gómez Y.*

Tecnologico Nacional de México / Instituto Tecnológico de Cancún, Kabah Km 3, Cancún, Quintana Roo, 77500, México

During the last years structural, mechanical and electrical properties of carbon nanotubes, graphene

and graphene oxides have allowed the development of a wide study field. Recently carbon

nanostructures (CN) pristine and doped with heteroatoms (CN-H) have demonstrated to be

excellent materials for different applications such as, wastewater treatment, hydrogen storage,

medical applications, as well as environmental sensors. Several authors have been reported

different synthesis methods to obtain CN-H. One of the most useful due to its efficiency, low cost

and capability to control the synthesis conditions is the chemical vapor deposition. In this research

work, different synthesis routes of CN-H (H: N2, S, Si and B) will be showed and their physical-

chemical properties will be discussed. The electrochemical performance showed relevant

electrocatalytic activities which allowed us to considerate these materials as good candidates for

electrocatalyst in fuel cells.

Acknowledgements.

This research was supported by “CONACyT-SENER-Sustentabilidad Energética” under grant No.

254667.


PCNN - 42


Electrical characterization in an Au-YSZ-Ru structure

Oscar A. Romo [*1,2]; Jorge Vázquez [3]; Jorge Jurado [1,2]; Sofía Espinoza[3]; Aron García [3]; E. G. Lizarraga-Medina [4]; H. Tiznado [4]

CONACYT - Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, B.C. – México; Centro de

Investigación Científica y Educación Superior de Ensenada - CICESE, Ensenada 22860, México; Universidad Autónoma de Baja California, Facultad de Ingeniería,

Arquitectura y Diseño-FIAD, Ensenada 22860, México;Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P.

22800, Ensenada, B.C. – México

Yttria-stabilized zirconia (YSZ) is the most widely used electrolyte material on energy storage

systems based on oxygen transport because of its high ion conductivity and excellent chemical

stability. However, this conductivity is obtained at high temperatures (800 °C) limiting its application

on lower temperature devices as sensors, electronic circuits, etc. Recent studies have shown a

reduction of the operating temperature by decreasing the thickness of YSZ, however, still there are

work to be done. In this work, we will study the ionic migration in YSZ thin films by galvanostatic

charge-discharge measurements at 150 °C. Here, the energy value and discharge-voltage shape

indicated the presence of ionic migration at this temperature. Furthermore, different oxygen

environments change the energy delivered and the shape of the discharged voltage due to the

number of arriving oxygens in the electrode-YSZ interface.

Acknowledgments

We would like to thank to PAPIIT: IN110018, IN112117, IA101018 PAPIME: PE100318 PE101317 and

FORDECyT: 272894

Also to M.C. David Dominguez


PCNN - 43


Confinement of supported Au nanoparticles with alumina by atomic layer deposition: their catalytic performance as nanoreactors in the 4-nitrophenol reduction

Liliana Vargas [*,1,2]; Elena Smolentseva [1]; Miguel Estrada Arreola [1]; Serguei Miridonov [2]; Hugo Tiznado [1]; Andrey Simakov [1]

UNAM; CICESE

More than 80% of the chemical processes in industry are accomplished thanks to heterogeneous

catalysts [1]. Nano-gold catalysts stand out among other supported systems because their

exceptional performance. In recent years the confinement of supported metal nanoparticles with

specific porous shells has been developed in order to improve its stability under reaction conditions

and thermal treatments [2]. Confined nanoparticles can be defined as nanoreactors immobilized on

a microscopic support. This configuration allows to separate them easily from the reaction media,

particularly in the gas phase.

In this work, gold nanoparticles of 2-3 nm in diameter supported on alumina and ceria were confined

by a 3 nm thick alumina porous shell, grown by atomic layer deposition (ALD), from Tri-methyl-

aluminium (TMA) and water. Obtained samples were characterized by TEM, N2 adsorption, FTIR in

situ and UV-Vis. Catalytic behavior was tested for the reduction reaction of 4-nitrophenol to 4-

aminophenol. The ALD experimental conditions (number of cycles and temperature), as well as the

nature of supports defined the characteristics of the final nanoreactors structure (core-shell or yolk-

shell), its catalytic performance, thermal stability and the reaction mechanism.

Acknowledgments

The authors appreciate the technical assistance of Dr. Eric Flores, Dr. Hugo Borbón, Dr. Javier López,

Francisco Ruiz, Jaime Mendoza, Ana Mizquez, Axel Ortiz and Fernando Solorio. The study was partly

supported by DGAPA (México) via project #203117, IN110018, IN112117 and IA101018. Liliana

Vargas thanks to CONACyT for their scholarship #488564.

References

1. De Jong K.P. (2009) Synthesis of solid catalyst. General aspects pag. 3. Germany:

Wiley&VCH Verlag GmbH & Co. KGaA

2. J. Zhang, J. Will Medlin. Catalyst design using an inverse strategy. Surface Science Reports, Vol.

73, 2018


PCNN - 44


Nanostructured TiO2-MWCNT Novel Materials for Eletrocatalytic Aplications

A. M. Valenzuela-Muñiz [1]; G. Rosado [2]; Y. Verde-Gómez[2]

CONACYT-TECNM/Instituto Tecnológico de Cancún, Av. Kabah Km. 3, 77500, Cancún, Quintana Roo, México;TECNM/Instituto Tecnológico de Cancún, Av. Kabah

Km. 3, 77500, Cancún, Quintana Roo, México.

Recently, studies about hybrid systems of metal oxides and multiwalled carbon nanotubes

(MWCNT) have been reported. The integration in a nanometric scale, of this type of materials,

allows the enhancement of some photo and electrochemical properties. By using an adequate

combination of synthesis methodologies, the nanometric size of the materials can be preserved,

allowing at the same time the creation of high surface area, and hence producing higher contact

areas to favor the application. In addition, by controlling the synthesis parameters the crystalline

phases of the materials can also be controlled; having then, tailored hybrid materials for different

applications. In this research work, nanostructured hybrid materials of TiO2-MWCNT with different

crystalline phases were obtained using the sol-gel methodology as well as a hydrothermal process.

The materials were characterized using scanning and transmission electron microscopy, energy

dispersive X-ray spectroscopy, thermogravimetric analysis, Raman spectroscopy, surface area

analysis (BET method) and X-ray diffraction. An extensive analysis and discussion of the obtained

results as well as the perspective of possible electrochemical applications will be presented at the

conference.


PCNN - 45


The first stage of ZnO nanostructures growth via controlled thermal oxidation: a combined experimental and theoretical study

H. Rojas-Chávez [1, *]; R. Farias [1]; O.E. Cigarroa-Mayorga [2]; H. Cruz-Martínez [3]; N. Cayetano-Castro [4]

UACJ-Departamento de Física y Matemáticas; CINVESTAV-DNyN; ITESM Campus Estado de México; IPN-CNMN

The growth of one-dimensional zinc oxide (ZnO) nano/micro needles arrays were obtained by using

a facile, reproducible and cost-effective method, namely controlled thermal oxidation. The

structural and morphological features of ZnO nano/micro needles were traced at the first stage of

growth using X-ray diffraction (XRD), focused-ion-beam (FIB), field emission scanning electron

microscopy (FE-SEM) and transmission electron microscopy (TEM). The mechanism insights into

elemental zinc oxidation on Zn surface was determined employing the deMon2k program, which

makes use of the auxiliary density functional theory (ADFT). The interaction of Zn surface with

oxygen molecules driven the possible initial stages of oxidation on the pure Zn surface. In this sense,

the experimental findings were complemented theoretically.


PCNN - 46


Mesoporous silica used like a drug delivery and derivates composites silica-carbon was proved as a a heterogenous catalyst

Herson R. [*1]; Roberto P. [2]

BUAP; BUAP

In the present work, mesoporous silica with a spherical morphology core-shell type were studied as

a drug delivery, the drugs studied were acetaminophen and dextromethorphan, the dosage of these

drugs carried out with phosphate buffer that simulated physiologic fluids. Hiybrid silica/surfactant

was used for to preparate silica-carbon composites. Subsequently, these organic-inorganic materials

were subjected to a controlled carbonization process, to convert the organic structuring template

of the mesoporous silica layer directly into carbon. Finally, the carbon layer of the composite

materials was functionalized with sulphonic acid groups, to be tested as catalysts in the dehydration

of 2-propanol and the esterification of oleic acid with methanol.


PCNN - 47


Characterization of modified natural mordenite with distinct levels of dealumination

Vitalii Petranovskii [1]; Aldo A. M. [*,1]; Miguel Ángel H. E. [2]; Karla Fabiola Q. E. [2]

UNAM - Center of Nanoscience and Nanotechnology;BUAP - Zeolites Research Department

Zeolites are microporous crystalline minerals composed of TO4 tetrahedra (where T can be Si or Al,

and O represents bridging oxygen atoms connecting neighboring tetrahedra) which can be arranged

in the crystal lattice in diverse ways, resulting in a complex framework with different porosities,

channels and cages. Natural zeolites are an attractive material for adsorption applications because

of their high abundance, low cost, and unique properties such as cation exchange, molecular sieving,

or catalysis.

Modification of natural zeolites by various acid treatments leads to an alteration of their properties

such as ion-exchange capacity, thermal stability, hydrophobicity, catalytic activity, as well as the

concentration and strength of acid sites. The main objective of this work is to study the modification

of the properties of natural mordenite, dealuminated with hydrochloric acid treatments.

The chemical composition of the final materials was determined by the method of Inductively

Coupled Plasma/Optical Emission Spectrometry (ICP/OES) technique. The crystal structures were

obtained by X-ray diffraction (XRD). The morphology of the materials was studied by Scanning

Electron Microscopy (SEM). Thermal properties were studied by means of Thermogravimetric

Analysis (TGA). The Lewis and Bronsted acid properties were investigated using Fourier-Transform

Infrared (FTIR) spectroscopy via ammonia and pyridine titration and Temperature Programmed

Desorption of ammonia (NH3-TPD).

Textural properties, such as surface area, pore volume and pore size, were obtained via N2

adsorption isotherms. Modified natural zeolites were evaluated as adsorbents by gravimetric,

volumetric, and gas-chromatographic methods for measuring adsorption values using methane and

carbon dioxide as probe molecules. The results obtained via adsorption isotherms (adsorption

parameters) by the three methods were compared to discuss the effect of dealumination level on

the adsorption capacity.


PCNN - 48


Au@CeO2 nanoreactors with different crystallinity of ceria shell obtained by hydrothermal method

Mario G. [2]; Serguei M. [2]; Andrey S. [1

UNAM; CICESE

Stability of the catalysts is one of the main goals in the field of catalysis, especially for noble metal-

based catalysts. Consequently, the synthesis and application of nanoreactors as new heterogeneous

catalysts with excellent stability have been extensively studied during last two decades [1,2].

Nevertheless, the synthesis of these materials still presents a lot of difficulties. In this work, the

synthesis of nanoreactors assisted by hydrothermal method has been presented. First, cerium oxide

hollow nanospheres (@CeO2) were obtained as reported by Jian Qi et al [3]. In order to modify the

structural properties of the @CeO2 different ratio between the ceria precursor (Ce(NO3)3*6H2O)

and the hydrolyzing agent (urea) was used. For the nanoreactors preparation, the obtained ceria

nanospheres were impregnated with a solution HAuCl4 10 mM, the mixture was kept under

vigorous stirring during 24 hours and then centrifuged. At that point, the solid precipitate was re-

dispersed in deionized water and reduced using NaBH4. Finally, the solid was recovered by

centrifugation and dried at 80oC during 12 hours. As was found, the ceria crystal mean size has an

effect on the catalytic performance of Au@CeO2 nanoreactors in the reduction of 4-nitrophenol to

4-aminophenol. On the other hand, it was shown that the accumulation of the product of the

reduction (4-aminophenol) in the reaction mixture affects the catalytic activity of the nanoreactors.


PCNN - 49


One-Pot synthesis of Au@Cex-Zry-O nanoreactors: active performance at low temperature at 4-nitrophenol reduction to 4-aminophenol

Sandra B. Aguirre[1]; Martin López Cisneros[1]; Elena Smolentseva[2]; Andrey Simakov[2]

Posgrado en Ciencia e Ingeniera de Materiales, Centro de Nanociencias y Nanotecnología Universidad Nacional Autónoma de México, Km. 107 carretera Tijuana -

Ensenada, Ensenada, Baja California, C.P. 22860 (México); Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 carretera

Tijuana -Ensenada, Ensenada, Baja California. 22860 (México)

Nanoreactors are nanostructured materials, whose inside chemical reactions occur. Their

application in catalysis is promoted by their superior catalytic stability and selectivity compared with

reference supported catalysts. The active metal of nanoreactors is kept in captivity by their specific

morphology that prevents sintering and aggregation, while the wall porosity acts as selective mesh

for the different reactants and products [1]. Usually multi-step techniques are used to synthesize

nanoreactors [2] which are characterized with low productivity and presence of multiple toxic

residues. One-pot techniques are a better option, which not produce dangerous residual substances

and, by other side they are scalable. The Spray Pyrolysis Technique (SPT) allows to synthesize

nanoreactors in one-pot mode and adjust their final morphology by synthesis parameters control

[3]. One of the numerous applications of such nanoreactors is the reduction of 4-nitrophenol (toxic

compound) to 4-aminophenol (paracetamol precursor) [4].

In the present work nanoreactors with gold cores and shell formed by CeO2-ZrO2 mixed oxides were

first synthesized by SPT and tested in the reaction of 4-nitrophenol reduction to 4-aminophenol. The

nanoreactors were synthesized using highly diluted aqueous solution of precursor salts

ZrO(NO3)2xH2O and Ce(NO3)36H2O with glycine as spherical nanostructure template, and an

aliquot of aqueous HAuCl4 solution for nuclei formation. The synthesis equipment includes four

coupled atomizers working at 2.4 MHz to produce an aerosol of precursor solution that is carried by

a gas flow ( 6 L/min) throw a tubular reactor with 9 independent heating zones(temperature profile

85-85-100-200-200-400-600-550-500 °C ), where each drop converts to a desired nanoreactor. It

was obteined spherical nanoreactors of different chemical composition of thin shell (~5 nm) with

excellent performance in the reaction of 4-nitrophenol reduction even at low temperature ( 5°C).


PCNN - 50


Comparative studio of Pt/C in the preparation of cathodic electrodes for fuel cells

N. Ortiz-Antolín [1]; G. I. Moreno-Grijalva [1]; M. T. Oropeza-Guzmán [1]; J. Cruz Reyes [2]; Y. Gochi-Ponce [1]

Tecnológico Nacional De México/Instituto Tecnológico de Tijuana; Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California

The electrodes preparation is essential in the design of Polymeric Electrolyte Membrane type fuel

cells (PEMFCs), since the electrocatalyst provides an energetically favorable path and the adsorption

and desorption of reagents can be carried out. Thus, it has been decided to synthesize nano-scale

materials to propose them as cathode electrocatalysts, due to the particle size and the

electrocatalytic activity, offering a maximum around 5 nm, it is important because the usual

morphology of the electrocatalysts in the electrodes of a fuel cell are based on nanoparticles that

form the electrocatalytic layer of a high specific area for electrochemical reactions, in the case of

the Oxygen Reduction Reaction (RRO). Additionally, it is also important to consider a reference

standard to compare the results, in this case, commercial platinum as an electrocatalyst.

On the other hand, the kinetics and the mechanism of the ORR must be considered because are

dependent on several experimental factors such as. the method of preparation, electrode material

and electrolyte. In this work to prepare the working electrode, 30 μL of the prepared sample

("electrocatalyst" 20 % wt. Pt/C Vulcan + Water) was deposited by dripping on glassy carbon to

perform the comparative studio through electrochemical measurements by cyclic and linear

Voltammetry, to determine the current density generated by the electrocatalysts analyzed. The

electrodes prepared were characterized by different physical techniques: SEM, RAMAN and TGA to

determine their morphology, composition and stability, as well as to analyze the results obtained

from the comparative analysis of different platinum materials.


PCNN - 51


GOOD PRACTICES FOR REPORTING PHOTOCATALYTIC EVALUATION OF VISIBLE-LIGHT ACTIVE SEMICONDUCTORS: Bi2O3 CASE STUDY

Agileo Hernández-Gordillo, Monserrat Bizarro, Ana Martínez, Sandra E. Rodil*

Instituto de Investigaciones en Materiales, UNAM

Photocatalysis is an important research subject these days due to its strong impact towards

sustainable development, however, we consider that relevant data and discussion about processes

that occur during photocatalysis are usually disregarded in many of the published papers.

Identification of processes such as (i) photodiscoloration due to adsorption or photolysis, (ii) dye

self-sensitization, (iii) actual photodegradation with the unavoidable formation of intermediate

products and (iv) mineralization of the intermediates products, is significant for the correct

interpretation of the photocatalytic activity of a semiconductor. In this paper, we remark the

importance of distinguishing the contribution of each of these processes on the reported data to

accomplish an adequate interpretation of the photocatalytic activity, proposing a follow-up work

plan to obtain the information and achieve a proper interpretation. To do so, we compared

theoretical and experimental absorbance spectra of three different dyes: Rhodamine-B (RhB), Acid

Blue 113 (AB) and Indigo Carmine (IC) during the photodegradation process. Photocatalytic

degradation of the dyes using the same semiconductor material (Bi2O3) was done using standard

spectrocolorimetric method but taking care to appropriately consider the processes mentioned

above. Furthermore, to evaluate the mineralization of these dyes as the product of the

photocatalytic degradation, total organic carbon (TOC) analysis was performed. The commonly used

evaluation of the results suggests that certain degree of photodegradation and mineralization was

achieved. However, a careful analysis indicates that it was mainly due to a decrease in the relative

concentration of the dye molecules because of their adsorption on the semiconductor’s surface,

and not due to a complete degradation.


PCNN - 52


ORGANOMETALLIC PRECURSORS OF HYDRODESULFURATION CATALYSTS: SYNTHESIS, CHARACTERIZATION AND EVALUATION

R.I. Hernandez Lima, J.N. Díaz de León, S. Fuentes-Moyado, G. Alonso-Núñez

Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 Carretera Tijuana-Ensenada, Ensenada, B.C., México

Abstract:

In the following work, three new precursors for hydrodesulfurization catalysts synthesis were

prepared from tetra-alkyl-phosphonium thiotungstate and widely characterized. The typical

synthesis was as follows: ammonium thiotungstate (ATT) and three different

tetraalkylphosphonium salts: Triphenyl [3[triphenyl phosphonio]propyl] phosphonium dibromide

(TPB), Benzyltriphenyl phosphonium Chloride (BPC) and Tributyl hexadecylphosphonium bromide

(THP) were diluted to obtain an aqueous solution. Then each aqueous solution was decomposed by

hydrothermal treatment for twelve hours at 180°C and finally calcined at 500°C for 5 h in a tubular

oven under Argon atmosphere to obtain the WS2 catalysts. The samples were labeled as T-TBP, T-

BPC, and T-THP. The Molecular structures of the precursor catalysts were characterized by UV-vis,

FT-IR, RMN-H, TGA and Mass spectrometry. The FT-IR spectra showed the presence of the functional

groups in the new compounds and NMR-H, TGA and Mass spectra helped to confirm their

organometallic structures. The obtained sulfided state catalysts presented poorly crystalline

structure. The catalytic activity was measured at three different temperatures 280°, 300° and 320°C

in a packed bed tubular reactor in descendent configuration at steady state conditions. The steady

state reaction rates of the 3-methylthiophene hydrodesulfurization reaction were obtained after

the system reach stabilization, and the conversion remains constant at each temperature. The

catalytic activity test has shown encouraging results.

Acknowledgments:

To SENER-CONACyT 117373 project for the financial support. Special thanks to E. Aparicio, M. A.

Estrada, Y. Kotolevich, F. Ruiz, Y. Esqueda and I. Gradilla for their expert technical assistance.


PCNN - 53


Adsorption of chlorinated compounds, alkanes and BTX in nanoporous Cu/SiO2, Fe/SiO2 and Ag/SiO2

Cynthia-Andriana G. [*,1]; Diana L. [*,1]; Miguel-Angel H. [2,1]; Maximiliano A. [3,1]; Silvia S. [3,1]

Depatamento de Investigación en Zeolitas, ICUAP, Benemérita Universidad Autónoma de Puebla, Puebla, 72570, México

Growing urbanization has led to an increase in the consumption of chemical products, which have

as a consequence the increase of pollution in water, soil and air. The agricultural sector has to need

to use pesticides to control organisms unwanted fields, to preserve the harvest and meet the

demand of its products, however, due to its toxic properties. The group of pesticides that present

greater persistence in the atmosphere corresponds to the called organochlorine compounds, they

are used in the agricultural area inordinately and persistent as affecting the atmosphere and human

health. These compounds are very easily spread through the air, water and soil, and are part of the

Volatile Organic Compounds (VOC’s), this characteristic volatility serves as indication in the

application of adsorption techniques. The objective of the project is to determine the adsorption

capacity of group of VOCs (dichloroethylene, trichloroethylene, tetrachloroethylene, carbon

tetrachloride, chlorobenzene, chloroform, C6-C8, benzene, toluene and Xylene) in silica (SiO2)

microporous doped with Cu, Fe and Ag at 2, 5 and 10 %, of this form to determine which of the silica

presents greater adsorption of this type of compounds. The adsorption isotherms obtained at

different temperatures and pressures in these nanomaterials are suitably treated with the relevant

equations in its form line and there are obtained their respective parameters: adsorption capacity.

Isotherms of adsorption data are used to estimate the degree and type of interaction, by a Clausius-

Clapeyron equation. In parallel the silica are characterized by physicochemical methods appropriate

to this kind of nanomaterials: High Resolution Adsorption (HRADS) in the area of pressures ranging

between 10-6-1, energy dispersive spectroscopy (EDS), Thermogravimetric Adsorption(TGA),

Fourier-transform infrared spectroscopy (IRTF) and Adsorption Chromatography at Low Degrees of

Coverage (ACLDC)


PCNN - 55


Effect of the cycles of cationic exchange, on the last size of silver nanoparticles in Zeolite “Y”

Jesus P. Hinojosa-Morán[1]; Humberto Velazquez-Vazquez[1]; Karla P. Valdez[1]; Karina V. Chávez[2]; V. Soto[*,2]

Universidad Técnica de Sinaloa, Carretera Municipal libre Mazatlan-Higueras Km. 3, Col. Genaro Estrada. C.P. 82199 Mazatlán Sinaloa México; Laboratorio del

Estado Sólido, Departamento de Química, Boulevard Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco, México.

The interest in the synthesis of nanomaterials is one of the most recurrent topics in recent years.

W. Baukelant et al. studied the optical properties of silver clusters in type "A" zeolite [1]. A.

Baldansuren et al. reported the ethylene and oxygen reaction in six-atom silver clusters in LTA

Zeolite [2]. M. El-Roz et al. found high catalytic activity under visible light in zeolitic materials

supporting silver clusters [3].

The ionic silver cation exchange method is a simple method that is used as a previous step to the

reduction of silver cations by hydrogen gas flow. The manipulation of the final size of the silver

nanoparticles is an interesting topic because the size of these defines the physical properties of the

nanoparticles.

In this work we study the final size obtained from silver nanoparticles, using several exchange cycles.

The global process consists of, exchange - reduction and again exchange and reduction up to four

times. The zeolite used is the "Y" type, with two different Si / Al ratios.

Acknowledgments

We would like to thank the Solid State Laboratory of the University of Guadalajara and professor

Eduardo Castañeda for technician support.

References

1- W. Baekelant et al., J. Phys. Chem. Lett., 9, (18) 5344-5350 (2018)

2- A. Baldansuren et al., J. Phys. Chem. C., 113, (45) 19623-19632 (2009)

3- M. El-Roz et al. ACS Appl. Mater. Interfaces, 2018, 10 (34), 28702-28708 (2018)


PCNN - 56


Effect of the reduction temperature on the final size of the silver nanoparticles supported on Zeolite "Y" with Si / Al = 15, ratio.

Liliana Plascencia*; Edgar B. Figueroa - Ochoa; V. Soto; K. Chávez.

Solid State Laboratory; Chemistry Department; University of Guadalajara

The zeolites are mesoporous aluminosilicate minerals, with their particular characteristic of carrying

out ion exchanges. The ion exchange is an intrinsic property in most zeolites. The interchanged

cation helps to stabilize the tetrahedral structure of the zeolite, which is electrically negative [1, 2,

3].

The formation of silver nanoparticles with different sizes leads to the differentiation of their

chemical, physical and optical properties [1]. In recent years the synthesis of nanoparticles has had

an exponential growth. However the studies that provide us information on the parameters that

control the final size are very scarce.

In this research work we studied the effect of the reduction temperature of the Ag+ ions exchanged

in the "Y" zeolite with Si / Al ratio = 15, in the final size of the synthesized silver nanoparticles, varying

the temperature in a range from 100 to 500 ° C.


PCNN - 58


Green synthesis and characterization of composites type silver nanoparticles-bivalve mollusk shell

Tannia Velazquez-Urbina [1]; Gabriel Alonso-Núñez [2]; Heriberto Espinoza-Gómez [3]; Lucía Z. Flores-López* [1]

CGI-ITT-TecNM;CNYN-UNAM;FCQI-UABC

Silver nanoparticles (AgNPs) are of interest, due to their optical, electrical and thermal properties

that present.

The biosynthesis of AgNPs using natural plant extracts has several advantages, among them the ease

of the synthesis process and that they can reduce and stabilize the nanoparticles (NPs) at the same

time.[1]

The preparation of nanocomposite materials can be carried out with the use of composite materials,

which have at least one of the particles dispersed in the matrix with nanometric dimensions.

Therefore, the addition of NPs results in a drastic improvement in their properties.[2]

In particular, to prevent the agglomeration of NPs, several natural materials have been used as a

support to improve their stability, separation and recovery. Also, these natural support materials

have turned out to be ideal, because they are economic and ecological.[3]

In the present research work it were prepared nanocomposites derived from AgNPs supported in

bivalve mollusk shell (mussel-type) by an in-situ method, using a natural leaf extract of Gardenia

jasminoides. The aqueous natural extract of G. jasminoides, was used as a reducing-stabilizing agent

at the same time of the NPs. The green synthesized AgNPs were characterized by UV-Vis, FT-IR and

TEM. By another hand, the nanostructured composites were characterized by FT-IR, FE-SEM, XRD,

Raman and TEM. The AgNPs synthesized by the natural extract were analyzed by TEM, obtaining a

mode of 11 nm. The composites of AgNPs-bivalve mollusk shell, were also corroborated by TEM,

resulting in a mode of 18 nm and with spherical morphology. Finally, in the future, these new green

nanocomposites will be ideal candidates to catalyze the degradation of toxic dyes.

References

1. Khodadadi, B.; Bordbar, M.; Yeganeh-Faal, A.; Nasrollahzadeh, M. J. Alloy Compd. 2017, 719,

82-88.

2. Paul, D. R.; Robeson. L. M. Polymer 2008, 49, 3187-3204.

3. Momeni, S. S.; Nasrollahzadeh, M.; Rustaiyan, A. J. Colloid Interf. Sci. 2017, 499, 93-101.


PCNN - 59


Obtention and Surface modification of cellulose nanocrystals extracted from agave bagasse

J. Ricardo González [1]; Martín Rabelero [2]; Luis Carlos Rosales [2]; Edgar Benjamín Figueroa [2]; Daniel Escobar [3]; J. Felix Armando Soltero [2]; Salvador García [4]; Emma Rebeca Macías [*,2]

Departamento de Ingeniería de Proyectos, Universidad de Guadalajara; Departamento de Ingeniería Química, Universidad de Guadalajara; Departamento de

Química, Universidad de Guadalajara; Departamento de Madera, Celulosa y Papel, Universidad de Guadalajara

By using the agave bagasse waste after the tequila production, nanocrystalline cellulose was

obtained following the alkaline pulping process in good yields. Partially sulfonated nanocrystalline

cellulose was obtained by acid hydrolysis process with H2SO4. This sulfonated group let us obtain

not only longer but also more reactive crystals. In order to study the miscellation process of large

molecules the sulfonated nanocrystals were made to react with cetyltrimethylammonium bromide

(CTAB) and cetyltrimethylammonium hydroxide (CTAOH) molecules. As a result an increase in

viscosity after 24h of reaction was appreciated. In addition, it was observed that this reaction may

be sensitive to temperature changes.


TIN - 1


Application of metal oxide nanofluids in a Compact Solar Collector

Joaquin-Alfredo Velázquez-Olvera[*1]; David Palomino-Merino [2]; Stephanía Velázquez-Olvera [1]; Enrique Barrera-Calva [1]; Eder Contreras-Gallegos [3]; Alfredo Cruz -Orea [3]

UAM Iztapalapa; ICAT UNAM; CINVESTAV IPN

One of the main uses of energy is the heating of fluids, mainly water and air. In the residential and

industrial sectors, energy applications are diverse, mainly; Prepared food, washing clothes and

personal hygiene, as well as the generation of steam and heat to process. The solar collectors

represented an excellent sustainable alternative to cover the needs of these sectors. In Mexico there

is a diverse market of brands and solar equipment, mostly of foreign origin. But those manufactured

in our country. With selective coatings, such as titanium oxide, they are imported, and the

substances and processes used are highly toxic and harmful to the environment. Given this, selective

organic coatings represent an excellent alternative. It is important to increase the thermal efficiency

of the solar collectors, as well as to improve the heat transfer in a thermal tank. For all the above,

this research proposes a solar collector for 15 liters of water with organic selective coating and the

support of a heat exchanger with nanofluid. So far, the best results are: thermal efficiency of 0.61

with a 0.1% concentration of ZnO nanofluid, thermal efficiency of 0.61 with a concentration of 0.1%

ZnCuO nanofluid and thermal efficiency of 0.65 with a concentration of 0.1% CuO nanofluid.


TIN - 3


CdSe-based thin film transistors with SiO2/PVP hybrid gate dielectric.

M.S. de Urquijo Ventura [1*]; M.G. Syamala Rao [1]; E. Flores Garcia [3]; M.A. Quevedo-Lopez [2]; R. Ramirez-Bon [1,2];

CINVESTAV;The University of Texas at Dallas; CIDESI

Organic-inorganic hybrid film SiO2-PVP, low temperature processed (200C), was synthesized by the

sol-gel process as gate dielectric for a thin film transistor, with CdSe semiconductor as the active

layer, deposited by sputtering at room temperature. The surface of the hybrid gate was analyzed by

SEM and AFM observing homogeneous and smooth surfaces, the optical properties by UV-Vis and

the composition by FTIR. To obtain the electrical properties of the dielectric was fabricate a MIM

structure, ITO, Hybrid dielectric, gold contacts, to get the leakage current and capacitance. For the

transistor fabrication, the hybrid gate dielectric layer was deposited on ITO by spin coating, then the

semiconductor, finally aluminum contacts by shadow mask. The mobility, on/off ration, threshold

voltage, and sub threshold swing were obtained from the electrical response of the devices analyzed

by the family curves and transfer characteristics.


TIN - 4


Composite materials of natural zeolite modified with N, P and organic nitrogenous substances for agroecological purposes

Esperanza Y. de la Nuez Pantoja [1]; Inocente Rodríguez Iznaga [1]; Vitalii Petranovskii [*,2]; Elena Smolentseva [2]; Gerardo Rodríguez Fuentes [1]; Ariel Martínez García [1]; Odalys Collazo García [1]

Instituto de Ciencias y Tecnología de Materiales (IMRE) – Universidad de La Habana. La Habana, Cuba; Centro de Nanociencias y Nanotecnología, Universidad

Nacional Autónoma de México, Ensenada, B.C. México

The development of novelty fertilizer materials, efficient and friendly to the environment is

constantly stimulated by the need to produce food for a world population in permanent growth [1].

The use of natural zeolites, with properties to support, exchange and release different nitrogenous

species, represents an attractive alternative that can be applied to develop fertilizers of controlled

release of nutrients with high utilization by the crop plants [2]. One of these zeolitic materials is the

NEREA product, carrier of nutrients (N, P, K and others) essential for crop plants and used as

substrates in zeoponic technologies [3]. The present work is aimed to study the effect on these types

of zeolitic fertilizers, with different N, P and K contents, a later treatment with aqueous solutions of

nitrogenous organic substances such as urea. The FTIR spectra of these materials showed the

presence of C = O and C-N bands, demonstrating the presence of urea on the zeolitic matrix. The

intensity of these bands is proportional both to the concentration of urea in the solutions and the

used contact time. The studies carried out on the release of these nutrients in water, after the

applied treatments, showed the capacity of these materials to release them slowly. The field tests

carried out with crop plants showed the improvements of these zeolitic fertilizers once treated with

urea.

Acknowledgments

The authors acknowledge the technical assistance from E. Aparicio, F. Ruiz, I. Gradilla, E. Flores, J.

Mendoza and J. Peralta, CNyN - UNAM. This research was supported by UNAM-PAPIIT, grant

IN107817 and the Post-degree Mobility Program of Macrouniversity Nets of Latin-America and the

Caribbean 2017.

References

1. X. Liu, Y. Yang, B. Gao, Y. Li, Y. Wan, ACS Sustainable Chem. Eng., 5, 6036 (2017)

2. T. Wea, M. Unonis, M. Khairuddin, S. Shaharuddin, N. Chai, J. Agri. Chem. Environ. 7, 1 (2018).

3. L. Rivero, G. Rodríguez-Fuentes. Proceeding 8th Int. Cong. Soilless Culture Soc. (1988)


TIN - 5


Design of optical ring resonator based on optical waveguides

Jose Daniel Castro Toscano [1*]; Eder Germán Lizárraga Medina[2]; David Salazar Miranda[1]; Heriberto Márquez Becerra[1]

CICESE,UNAM

Integrated optics is the application and manipulation of physical lighting phenomena for the

obtaining miniaturized devices that can be used in myriad of nanophotonic technologies. One of

these devices are the optical ring resonators, which are critical in the area of integrated optics by

the fact of filtering optical signals at micrometric distances, leaving behind filtering and resonance

methods that need a large free space (higher than micrometric distances), being a great bet for the

development of miniaturized structures. Starting with the objective of the work, which consists of

design of ring resonators, for the search of a more compact and functional design for the integrated

optics. Here are presented principle of operation of a ring resonator based on optical coupling of

Bus Waveguide, and Circular Resonator and initial results for optical waveguide simulation based on

dielectric materials with high refractive index such as: Al2O3 , Y2O3 y TiO3; and substrate of silice

(SiO2). Optical performance of a basic optical resonator using Comsol and Matlab software, at a

wavelength of 1550nm that is used for optical communications is included.

Acknowledgments

We acknowledge to CONACyT (Grant No. 632147), as well as Dr. Alma Georgina Navarrete Alcalá,

Dr. Hugo Jesus Tiznado Vazquez.


TIN - 7


Low cost instrumentation system for Van der Pauw measurements

E. Murillo-Bracamontes [*,1], C.A. Lopez-Mercado [1], E.G. Lizarraga-Medina [1], Irving Fernández [1], J. López [1], J.J. Gervacio-Arciniega [2], H. Tiznado [1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, B.C. – México; CONACYT-Facultad de

Ciencias Físico-Matemáticas, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 18 sur, Col. San Manuel Ciudad Universitaria, Puebla, Pue. 72570,

México

The characterization of nanostructured materials and semiconductor devices often involve

determining their resistivity. The four-probe or Kelvin technique is well suited to measure he

resistivity of two-terminal devices. In this type of measurement, four probes are placed on the

sample: two of the probes are used to apply current and the other two probes are used to measure

the voltage. One common Kelving technique to characterize the resistivity of a nanostructured

material or a semiconductor thin film of uniform thickness is the Van der Puaw method where the

source current and the voltage measurement is alternated using the four probes placed on the

samples.

On this work a low cost instrumentation system was designed to automatically switch the electrical

current and voltage signals to the four probes placed on the sample under test. The system consists

of a microcontroller that control the switching signals from the electrical equipment to the four

probes on the sample without using mechanical switches. The sourcemeter Keithley 2450 was used

to apply a constant current and measure the voltage. A probe station was used to perform the

electrical contacts between the instrumentation system and the sample. The instrumentation

system and the sourcemeter are synchronized by a software developed in Labview. Thin films of

alumina deposited by atomic layer deposition (ALD) were characterized.


IN110018, IN112117 and PAPIME PE100318, PE210219, PE109917 and PE101317 projects, and

CONACyT through the FORDECyT project 272894. The authors would like to thank David Dominguez

and Victor García Gradilla for technical assistance.

References

1. D.V. Ryazantsev and V.P. Grudtsov, “Automatic Parameter Extraction Technique for MOS

Structures by C-V Characterization Including the Effects of Interface States”, Measurement Science

Review, vol 16, no. 5, pp. 266–272, 2016.


TIN - 8


Low temperature processing of HfAlOx-PVP hybrid films with applications to electronic devices.

Javier Meza Arroyo* [1];

CINVESTAV

In this work, we explore the synthesis of inorganic-organic HfAlOx-PVP hybrid films by a low

temperature sol-gel process. The hybrid films were deposited by spin coating process and annealed

at 200 C in air. The characterization of hybrid films was performed by UV-VIS spectroscopy, FTIR,

AFM, SEM, C-V and I-V measurements. The hybrid film has a proper link between organic and

inorganic phases with strong bond, supported by the high optical transparency and homogeneity.

At microscopic level, the hybrid films have uniform, flat and smooth surface with surface roughness

lower than 1 nm. The C-V and I-V measurements performed on MIM structures showed good

properties to be used in electronic devices. The present work can be useful to future opto-

electronics devices at low temperature and cost-effective process.

Key Words: sol-gel, low-temperature, hybrid gate dielectrics, opto-electronics devices.


TIN - 9


Prototype design for energy storage nano-devices of low current and high temperature operation

C.A.Lopez-Mercado [*,1,2]; E. Murillo [1]; E.G. Lizarraga-Medina [1]; Christian Bizueth [2]; Alfredo Espinoza [2]; Mario Anguiano [2]; H. Tiznado [1]

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 14, C.P. 22800, Ensenada, B.C., México; 2Universidad

Autónoma de Baja California. Carretera Transpeninsular Ensenada-Tijuana Número 3917, Colonia Playitas, C.P. 22860, Ensenada, B.C., México

The characterization of nano-energy storage devices is usually done by expensive sophisticated

laboratory equipment which keeps low noise and current consumption in the measurements. These

equipment are necessary to study the electric performance and his energy storage capacity avoiding

external noise. However, to show the device functionality in a prototype while keeping the low

noise operation level and additional features as temperature control, an electronic design is

required.

In this work, we present a prototype to light a LED with a nano energy storage device fabricated by

ALD, here the low current noise and high operation temperatures where solved by an electronic

design. This advance electronic design is capable of handling analogue switches to generate two

parallel and serial configurations to charge and discharge the energy storage device, respectively.

Furthermore, a monitoring, stabilization and temperature controller was developed in order to

operate from room temperature to 200 ºC.


IN110018, IN112117 and PAPIME PE100318, PE210219 and PE101317 projects, and CONACyT

through the FORDECyT project 272894. The authors would like to thank Dr. Hugo Borbon, David

Dominguez, Alejandro Tiznado and Enrique Medina, for technical assistance.


TIN - 10


Synthesis of AlN & TiN thin films: An optical emission spectroscopy study

Itayeé Sierra [*,1]; Julio Cruz [1]; Noemí Abundiz-Cisneros [2]; Juan Águila-Muñoz [2]; Roberto Machorro [1]; Roberto Sanginés [2]

Centro de Nanociencias y Nanotecnología, UNAM; CONACyT, Centro de Nanociencias y Nanotecnología, UNAM

Reactive magnetron sputtering is one of the most popular techniques to deposit high-quality thin

films of compounds, it is preferred because it can produce controllable stoichiometry thin films and

can perform on industrial scale. One major drawback of this technique is target poisoning which

consist in compound formation on the target surface. This promotes the possible unknowingness of

optimal conditions to deposit thin films.

AlN and TiN were chosen due to their wide range of applications. AlN is used for optical devices,

acousto-optic devices and it is considered a good piezoelectric, whereas TiN is known as a hard

coating on machine tooling besides it is used to coat costume jewelry and in decorative purposes

because of its golden appearance.

Thin films of AlN and TiN, respectively, were deposited via reactive magnetron sputtering varying

deposition parameters: work pressure, gases flux ratio (Ar and N2) and source power. Hysteresis

curves were obtained during deposition to study target poisoning. Optical emission spectroscopy

(OES) was used to monitor the different emission lines coming from the plasma.

The deposition parameters and OES analysis were correlated to establish the optimal conditions to

obtain certain type of thin films.


TIN - 11


Low-temperature evaluation of state charge of the nanostructured Au-YSZ-Ru fuel cell.

J.L. Vazquez [*,1]; H. Tiznado [1]; E. Lizarraga [1]; O. Romo [2]; C. López [1]; F. Solorio [3]

Centro de Nanociencias y Nanotecnología (CNyN); Centro de Investigación Cientifica y de Educación Superior de Ensenada (CICESE); Universidad Autónoma de Baja

California (UABC)

In this work the design of low temperature 150 oC operation of solid oxide fuel cell (SOFC) in terms

of remaining available capacity at different electrical disconnection times is reported. For cell

fabrication, ruthenium thin film growned by RF-sputtering as a fuel electrode (anode), Yttria-

stabilized zirconia (YSZ) by atomic layer deposition (ALD) as an electrolyte and Au by thermal

evaporation as air electrode (cathode). Electrical properties were measured in air by galvanostatic

technique using an SMU Keithley 2450 and 4V was applied to start a typical load of a fuel cell.

Focused mainly on discharge curves at different electrical disconnection times after a fixed load,

characteristic discharge curve of a battery was observed for nearly all them. At disconnection short

times 0-2 minutes, energy densities decreased in the 34.5-15.32 Wh/l range. Disconnection on 5-30

minutes shows a small increment 16.28-21.0 Wh/l and large decrement at 1-14h 20.66-0.81 Wh/l.

Acknowledgment

M.C. David Dominguez, students Aarón García and Sofía Espinoza

Documents

PROCEEDINGS - NNSymposium · ORGANIZING COMMITTEE Ernesto Cota Araiza Chairman • Andrés Zarate Romero • Carolina Bohórquez Martínez • Francisco Mireles Higuera • Javier