Polymat...in the chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi reaction of aldehydes gave the corresponding alcohols with a maximum enantioselectivity of 93 %. 10 In a systematic

PolymatContributions

ProceedingsVolume 1

PHOSPHORUS DENDRIMERS HYPERBRANCHED MACROMOLECULES FOR NANOSCIENCES

Anne-Marie Caminade12

1 CNRS LCC (Laboratoire de Chimie de Coordination) 205 route de Narbonne BP 44099 F-31077 Toulouse Cedex 4 France E-mail anne-mariecaminadelcc-toulousefr

2 Universiteacute de Toulouse UPS INPT F-31077 Toulouse Cedex 4 France

Dendrimers [1] are hyperbranched macromolecules constituted of repetitive monomeric units as polymers but they are never synthesized by polymerisation reactions Dendrimers have a perfectly defined 3D structure thanks to their step-by-step synthesis layer after layer Each time an additional layer of branching points is added a new generation is created Among the diverse types of dendrimers phosphorus-containing dendrimers in particular polyphosphorhydrazone dendrimers [2] occupy a special place due to their numerous properties as illustrated in Figure 1

Figure 1 Chemical structure of a second generation polyphosphorhydrazone dendrimer Properties and uses of this family of dendrimers depending on the nature of the terminal groups R

A few typical examples of these properties will be given below concerning catalysis nanomaterials and biologynanomedicine

Vol 1 Pag1

The use of dendrimers for catalysis concerns in general dendrimers having catalytic entities as terminal functions The expected properties are an easy recovery as the dendrimers have a larger size than the products and reagents and possible synergistic effects due to the proximity of the catalytic sites which may afford better results than monomeric catalysts for instance increased yields In the case of phosphorus dendrimers mainly positive dendritic effects [3] have been observed for the outcome of catalysis The main types of ligands linked as terminal functions of phosphorus dendrimers and the metals used for their complexation are shown in Figure 2 These dendrimers have been used in most cases for catalyzing C-C couplings The most salient features when using dendritic catalysts are i) an easy recovery and re-use of the dendritic catalysts up to 12 times by precipitation or by magnetic recovery [4] and even with an increased efficiency (yield) when entrapping Pd nanoparticles [5] ii) an increased yield when the generation of the dendrimer increases but using an identical number of catalytic sites (for instance 12 equivalents of monomeric catalyst compared with one equivalent of a first generation dendrimer bearing 12 catalytic entities as terminal functions) [6] an increased enantiomeric excess when the generation increases [7] and the possibility to switch ONOFF the catalytic activity by modifying the redox properties [8]

Figure 2 Types of ligands used as terminal functions of phosphorus dendrimers for the complexation of different metals The corresponding complexes have been used as catalysts most generally for C-C couplings

In the field of materials dendrimers have been used either for creating new nanomaterials incorporating dendrimers or for modifying at the nanoscale the surface of existing materials

Vol 1 Pag2

Mesoporous silica[9] ordered titanium oxide clusters[10] and rigid hydrogels [11] pertain to the first cases Modified electrodes[12] and elaboration of biological sensors [13] pertain to the second cases Nanotubes [1415] exclusively constituted of dendrimers have been also obtained thanks to electrostatic interactions between positively and negatively charged dendrimers Most examples of polyphosphorhydrazone dendrimers used in the field of materials have as terminal functions those shown in Figure 3

Figure 3 Selected examples of terminal functions of phosphorus dendrimers used for creating of modifying nanomaterials

In the field of biology the dendrimers need to be soluble in water[16] Water-solubility of phosphorus dendrimers is afforded by the terminal groups selected examples are shown in Figure 4 These dendrimers can be used for drug delivery or as drugs by themselves Phosphorus dendrimers ended by ammonium groups are useful for transfection experiments to help negatively charged biological entities (DNA RNA plasmids etc) to penetrate inside cells[17] These dendrimers have also anti-prion activities[18] including in vivo [19] Negatively charged dendrimers (carboxylate terminal functions) interact with positively charged drugs to facilitate their delivery This includes drugs against HIV[20] and to treat ocular diseases[21] Drugs can be covalently linked to the surface of dendrimers such as mannose derivatives which prevent in vivo the acute inflammation of lungs[22] However some dendrimers can be drugs by themselves it means that the functions of their surface have no special properties but they become active when linked to the dendrimers This is in particular the case of azabisphosphonic groups The as functionalized dendrimers have many properties towards the human immune sytem[23] In a study for a structureactivity relationship many different phosphonic derivatives have been synthesized The biological properties discovered include the multiplication of Natural Killer (NK) cells[24] and anti-inflammatory properties against reumathoid arthritis[25] and multiple sclerosis [26]

Figure 4 Selected examples of water-soluble terminal functions of phosphorus dendrimers used in the field of biology

Vol 1 Pag3

References [1] Caminade A-M Turrin C-O Laurent R Ouali A Delavaux-Nicot B Editors DendrimersTowards Catalytic Material and Biomedical Uses John Wiely amp Sons Ltd Chichester UK 2011[2] Launay N Caminade A M Lahana R Majoral J P Angew Chem Int Ed Engl 1994 331589-1592[3] Caminade A M Ouali A Laurent R Turrin C O Majoral J P Chem Soc Rev 2015 443890-3899[4] Keller M Colliere V Reiser O Caminade A M Majoral J P Ouali A Angew Chem Int Ed2013 52 3626-3629[5] Badetti E Caminade A M Majoral J P Moreno-Manas M Sebastian R M Langmuir 200824 2090-2101[6] Ouali A Laurent R Caminade A M Majoral J P Taillefer M J Am Chem Soc 2006 12815990-15991[7] Garcia L Roglans A Laurent R Majoral J P Pla-Quintana A Caminade A M ChemCommun 2012 48 9248-9250[8] Neumann P Dib H Caminade A M Hey-Hawkins E Angew Chem Int Ed 2015 54 311-314[9] Turrin C O Maraval V Caminade A M Majoral J P Mehdi A Reye C Chem Mater 200012 3848-3856[10] Soler-Illia G Rozes L Boggiano M K Sanchez C Turrin C O Caminade A M MajoralJ P Angew Chem Int Ed 2000 39 4250-4254[11] Marmillon C Gauffre F Gulik-Krzywicki T Loup C Caminade A M Majoral J P Vors JP Rump E Angew Chem Int Ed 2001 40 2626-2629[12] Le Derf F Levillain E Trippe G Gorgues A Salle M Sebastian R M Caminade A MMajoral J P Angew Chem Int Ed 2001 40 224-227[13] Le Berre V Trevisiol E Dagkessamanskaia A Sokol S Caminade A M Majoral J PMeunier B Francois J Nucleic Acids Res 2003 31 8[14] Kim D H Karan P Goring P Leclaire J Caminade A M Majoral J P Gosele USteinhart M Knoll W Small 2005 1 99-102[15] Caminade A M Majoral J P Chem Soc Rev 2010 39 2034-2047[16] Caminade A M Hameau A Majoral J P Chem-Eur J 2009 15 9270-9285[17] Loup C Zanta M A Caminade A M Majoral J P Meunier B Chem-Eur J 1999 5 3644-3650[18] Ottaviani M F Mazzeo R Cangiotti M Fiorani L Majoral J P Caminade A M PedziwiatrE Bryszewska M Klajnert B Biomacromolecules 2010 11 3014-3021[19] Solassol J Crozet C Perrier V Leclaire J Beranger F Caminade A M Meunier BDormont D Majoral J P Lehmann S J Gen Virol 2004 85 1791-1799[20] Blanzat M Turrin C O Aubertin A M Couturier-Vidal C Caminade A M Majoral J PRico-Lattes I Lattes A ChemBioChem 2005 6 2207-2213[21] Spataro G Malecaze F Turrin C O Soler V Duhayon C Elena P P Majoral J PCaminade A M Eur J Med Chem 2010 45 326-334[22] Blattes E Vercellone A Eutamene H Turrin C O Theodorou V Majoral J P CaminadeA M Prandi J Nigou J Puzo G Proc Natl Acad Sci U S A 2013 110 8795-8800[23] Caminade A M Fruchon S Turrin C O Poupot M Ouali A Maraval A Garzoni M MalyM Furer V Kovalenko V Majoral J P Pavan G M Poupot R Nature Comm 2015 6 7722[24] Griffe L Poupot M Marchand P Maraval A Turrin C O Rolland O Metivier P BacquetG Fournie J J Caminade A M Poupot R Majoral J P Angew Chem Int Ed 2007 46 (14)2523-2526[25] Hayder M Poupot M Baron M Nigon D Turrin C O Caminade A M Majoral J PEisenberg R A Fournie J J Cantagrel A Poupot R Davignon J L Science Transl Med 20113 11[26] Hayder M Varilh M Turrin C O Saoudi A Caminade A M Poupot R Liblau R SBiomacromolecules 2015 16 3425-3433

Vol 1 Pag4

Enantioselective Catalysis with 3d Transition Metal Complexes Chiral Pincers as Stereodirecting Ligands

Lutz H Gade Anorganisch-Chemisches Institut Universitaumlt Heidelberg Im Neuenheimer Feld 270 69120

Heidelberg

Meridionally coordinating chiral tridentate ligands frequently referred to as ldquopincersrdquo1 provide the structural platform for the construction of efficient stereodirecting molecular environments Whilst many of the known chiral systems of the ldquopincerrdquo type perform relatively poorly in enantioselective catalysis due to certain lack of control of substrate orientation the assembly from rigid heterocyclic units recently has given rise to several highly enantioselective catalysts2 In particular five different classes of pincer ligands [Cbzbox (1)3 BOPA (2)4 Boxmi (3) BPI (4) and PyrrMeBOX (5) Figure 1] which contain a central anionic nitrogen σ-donor and two pendant lone pair donors from nitrogen atoms in oxazoline or pyridine rings have given rise to highly active and selective catalysts The focus has been initially on the asymmetric Nozaki-Hiyama-Kishi coupling of aldehydes with halogenated hydrocarbons34 and subsequently on the development of Lewis acid catalysts involving an enantioselective electrophilic attack inter alia onto metal activated β-ketoesters and oxindoles Increasingly these stereodirecting ligands are being employed in other types of transformations including hydrosilylations cyclopropanations and epoxidations which will be reviewed in the final section of this overview5

O N N O

1Cbzbox BOPA

2Boxmi

PyrrMeBOX

Figure 1 Chiral tridentate N^N^N pincer ligands discussed in this report

Our work originally focused on the PyrrMeBox pincers 5 which we reported in 20036 However after the development of an improved synthetic access to their protio-precursors7 their applications have only recently begun to be explored in particular in nickel catalysis involving one-electron redox steps8 The chiral BPI derivatives 4 were found to be efficient stereodirecting ligands for Co catalysed hydrosilylations and cyclopropanations9 Their use in enantioselective iron-catalyzed hydrosilylations of ketoned provided one of the first examples of its kind in 20089a More recently we recently reported the synthesis of a new class of chiral N3 pincer ligands bis(oxazolinylmethylidene)isoindolines (boxmi 3) which are readily accessible in the modular three-step synthesis (starting from easily available phthalimides10

Vol 1 Pag5

These ligands were were initially tested in the nickel(II)-catalyzed enantioselective fluorination of oxindoles and β-ketoesters yielding the corresponding products with enantioselectivities of up to gt99 ee and high yields Application of the chiral pincer ligands in the chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi reaction of aldehydes gave the corresponding alcohols with a maximum enantioselectivity of 93 10

In a systematic study the highly enantioselective alkylation of β-ketoesters was achieved using boxmi-copper(II) catalysts In particular benzylic and allylic alcohols were employed to in situ prepare the corresponding iodides as the alkylating reagents without further purification The primary chiral alkylation products were cyclized subsequently in a one-pot procedure to generate spirolactones or bi-spirolactones by adding BF3 Et2O and in the presence of the copper catalyst11 The corresponding Cu-catalyzed enantioselective alkylation of oxindoles was hampered by radical processes In this case the use of zinc based catalysts gave the corresponding products in high yields and enantioselectivities12

Furthermore β-ketoester-substituted allylsilanes were converted to spirolactones and bicyclic cyclopentanols with excellent enantioselectivities by subsequent treatment of the primary chiral allylation products (Scheme 1)11

Scheme 1 Stereoselective synthesis of allylsilanes and their subsequent transformations (L = Ph-boxmi)

Employing the chiral Cu-pincer systems developed for enantioselective alkylations described above we extended the concept to include the asymmetric catalytic trifluoromethylation of β-ketoesters under mild conditions by using Tognirsquos electrophilic trifluoromethylating agent 3-Dimethyl-1-(trifluoromethyl)-12-benziodoxole In this way a broad range of cyclic five-membered ring β-ketoesters were trifluoromethylated with excellent enantioselectivity (Scheme 2)13 Similar reactivity and enantioselectivity was also achieved in the corresponding enantioselective electrophilic trifluoromethylthiolations14

Scheme 2 Enantioselective trifluoromethylation of five-membered ring β-ketoesters (L = Ph-boxmi)

Exploiting a similar strategy as for the enantioselective trifluoromethylation described above a highly enantioselective Fe-catalyzed azidation of β-ketoesters and oxindoles was developed by using a T-shaped iodine(III) compound as azido-transfer reagent (Scheme 3) In this way an efficient protocol for enantioselective Fe-catalyzed azidation of cyclic β-ketoesters and 3-aryl oxindoles was achieved15

Vol 1 Pag6

2bc gt95 98 ee

2ec gt95 99 ee

2cc gt95 98 ee

2gc gt95 99 ee

2ac gt95 99 ee

2oc gt95 94 eea

2jc gt95 94 ee

nC6H13

OHnC11H23

2kc gt95 95 ee

2lc gt95 99 ee

2mc gt95 99 ee

2ic 56 73 ee

Scheme 3 Fe(boxmi)-catalyzed enantioselective azidation of cyclic β-ketoesters

The cyclic β-ketoesters were converted to the corresponding products in high yields with up to 93 ee catalyzed by the combination of iron(II) chlorido complex and silver carboxylate 3-Azido aryl oxindoles were obtained with up to 94 ee using the catalyst prepared by iron(II) propionate and ligand in situ The α-Azido esters could be converted smoothly into α-amino ester by palladium-catalyzed hydrogenolysis which may provide a useful method for the synthesis of highly substituted α-amino acid derivatives On the other hand copper-catalyzed azide-alkyne 13-dipolar cycloaddition (CuAAC) converted the α-azido esters into the corresponding triazoles in high yield15

Using the boxmi ligand as stereodirecting pincer ligand we developed iron(II) boxmi complexes as catalysts for the catalytic hydrosilylation of ketones initially employing acetate complexes as precatalysts which displayed a remarkable enantioselectivity but the usual low reactivity also found for other Fe acetate precatalysts However the corresponding alkyl or alkoxide precatalysts gave rise to highly active and enantioselective catalysts which match the top performers based on noble metals for the hydrosilylation of ketones (Scheme 4)16

a) [Fe] (5 mol)(EtO)2MeSiH

deg(2 equiv) toluene -78 C - rt 6 h

b) K2CO3MeOH rt 1 hR R

2dc gt95 93 ee

2hc gt95 99 ee

2fc gt95 99 ee

2nc gt95 99 ee

Scheme 4 Substrate Scope of the Iron-catalyzed Hydrosilylation of Ketones

This has led us to a systematic study of the mechanistic pathway(s) involved in the iron-catalyzed hydrosilylation of ketones as well as the activation pathway which converts the frequently employed carboxylate precatalysts to the catalytically active species The proposed reaction mechanism is characterized by a rate-determining σ-bond metathesis of an alkoxide complex with the silane subsequent coordination of the ketone to the iron hydride complex and insertion of the ketone into the FeminusH bond to regenerate the alkoxide complex (Scheme 5)17

Vol 1 Pag7

OFe(boxmi)OR (EtO)2MeSiH

gt 95 yieldgt 95 ee (up to gt 99 ee)

LigFe-OR

[LigFe-H]

FeLigH

LigFe-OAc

this workprecatalystactivation

R wide range of alkyl and aryl substituents

Scheme 5 Proposed mechanism of the Fe-catalyzed hydrosilylation of ketones

References

(1) (a) D Morales-Morales C M Jensen The Chemistry of Pincer Compounds ElsevierAmsterdam 2007 (b) G Van Koten D Milstein Topics in Organometallic ChemistryVol 40 Springer Heidelberg 2013 (b) G Van Koten R Gossage Topics inOrganometallic Chemistry Vol 54 Springer Heidelberg 2013

(2) H Nishiyama Chem Soc Rev 2007 36 1133(3) T Suzuki A Kinoshita H Kawada M Nakada Synlett 2003 570(4) H A McManus P J Guiry J Org Chem 2002 67 8566(5) Q-H Deng R L Melen L H Gade Acc Chem Res 2014 47 3162(6) C Mazet L H Gade Chem Eur J 2003 9 1759(7) (a) F Konrad J Lloret Fillol H Wadepohl L H Gade Inorg Chem 2009 48 8523

(b) F Konrad J Lloret Fillol C Rettenmeier H Wadepohl L H Gade Eur J InorgChem 2009 4950

(8) (a) C Rettenmeier H Wadepohl L H Gade Chem Eur J 2014 20 9657 (b) C ARettenmeier H Wadepohl L H Gade Angew Chem Int Ed 2015 54 4880 (c) JWenz C A Rettenmeier H Wadepohl L H Gade Chem Commun 2016 52 202 (d)C A Rettenmeier H Wadepohl L H Gade Chem Sci 2016 7 3533

(9) (a) B K Langlotz H Wadepohl L H Gade Angew Chem Int Ed 2008 47 4670(b) D C Sauer H Wadepohl L H Gade Inorg Chem 2012 51 12948

(10) Q-H Deng H Wadepohl Lutz H Gade Chem Eur J 2011 17 14922(11) Q-H Deng H Wadepohl L H Gade J Am Chem Soc 2012 134 2946(12) T Bleith Q-H Deng H Wadepohl L H Gade Angew Chem Int Ed 2016 55

7852(13) Q-H Deng H Wadepohl L H Gade J Am Chem Soc 2012 134 10769(14) Q-H Deng C Rettenmeier H Wadepohl L H Gade Chem Eur J 2014 20 93(15) Q-H Deng T Bleith H Wadepohl L H Gade J Am Chem Soc 2013 135 5356(16) T Bleith H Wadepohl L H Gade J Am Chem Soc 2015 137 2456(17) T Bleith L H Gade J Am Chem Soc 2016 138 4972

Vol 1 Pag8

STUDY OF PLASTICIZING EFFECT OF AGAVE SYRUP OF THERMOPLASTIC STARCH (TPS) BIOFILMS BY METHOD OF EXTRUSION AND CASTING

Casas-Gonzaacutelez MR1Rodriacuteguez-Gonzaacutelez FJ1

1Polymers Processing Department Centro de Investigacioacuten en Quiacutemica Aplicada CP 25294 Saltillo Coahuila Mexico

email mayela700hotmailcom

INTRODUCTION TPS has been considered a potential candidate for the development of edible biofilms due to their thermoplastic behavior (Mali et al 2005) TPS biofilms can be obtained by different processing techniques such as casting (Maran JP et al 2013) and extrusion method (Li M et al 2011) where the starch is gelatinized and plasticized under high shear stress TPS has been obtained from the disruption of starch granule in the presence of high-boiling point plasticizers (Bastioli 2001) The most commonly used plasticizer is glycerol (Fang et al 2004) On the other hand agave syrup is a source of sugars obtained after scraping stalks Agave salmiana It is rich in sugars (such as maltose and fructose) dextrans and polysaccharides such as inulin in addition to fructooligosacharides (FOS) also contains concentrations of maltooligosaccharides (Casas-Gonzalez 2012) which can be used as plasticizers The objective of this work was to compare the plasticizing action of agave syrup and glycerin in TPS biofilms prepared by extrusion and casting methods

MATERIALS AND METHODS

Potato starch was acquired from Penford Food (France) Glycerol was purchased from Proquisa-Mexico and agave syrup Agroindustries Faroc (Mexico) Films of potato starch were prepared by 1) Casting In a jacketed reactor a suspension at 10 solids (starch + plasticizer) was gelatinized at 90degC for 30 min The filmogenic solution was deposited on polystyrene plates and evaporated at 60degC for 16 h Biofilms were formulated with agave syrup (TPSM) or glycerol (TPSG) in concentrations of 30 35 40 with respect to starch 2) Extrusion A suspension of starch-plasticizer-water was fed to the feeding zone of a twin-screw extruder ZSK30 (Werner amp Pfleiderer) equipped with 9 heating zones at a rate of 35 kh 150 rpm and 90ordmC (Tena-Salcido et al 2008) TPS extruded films plasticized with glycerol (TPSGE) and agave syrup (TPSME) were stored in a desiccator before characterization Water absorption and water solubility indexes (WAI and WSI respectively) were determined by the method described by Anderson et al (1969) and the relative loss of plasticizer (RLP) was calculated according to Casas-Gonzalez et al (2014) The DMA measurements were performed using a TA-Instruments DMAQ800 equipment under multifrequency mode operation from -150deg to 150degC at 5 degCmin a frequency of 1Hz and amplitude of 20 microm used Dual Cantilever clamp

Vol 1 Pag9

RESULTS AND DISCUSSION Biofilms prepared by extrusion showed lower WAI values than those obtained by casting (Table 1) The decrease in WAI could be attributed to the alignment of starch molecules during both the pass through the die and the process of calendering Rodriguez-Castellano (2013) mentions that increasing screw speed thermally damaged starch WAI reducing due to starch degradation Moreover TPSGE biofilms have WAI values higher than those of TPSME biofilms WAI values of TPSGE tended to be higher because glycerol has better plasticizing action than sugars as might be the case agave syrup (Van der Burgt et al 1996 and Mathew A P et al 2002)

Method Sample WAI (gg) WSI () Relative loss of plasticizer ()

Casting

TPS-0 15788 820 0 TPS-G30 16085 1710 38 TPS-G35 12394 1980 41 TPS-G40 11985 3330 70 TPS-M30 12194 1910 44 TPS-M35 12675 2260 49 TPS-M40 14679 2640 54

Extrusion TPS-G30E 7444 2300 58 TPS-G35E 5056 2530 57 TPS-G40E 6451 2960 62 TPS-M30E 3381 2390 61 TPS-M35E 2846 2930 68 TPS-M40E 3331 3090 65

Table 1 Effect of type and concentration of plasticiser in TPS biofilms

In the case of WSI it was observed that biofilms obtained by casting have lower than those prepared by extrusion It is probable that the depolymerization underwent by starch during the high-shear processing increased the soluble fraction of TPSE (Fakhouri F M et al 2013) On the other hand WSI values were also dependent of the plasticizer content thus the higher the concentration of plasticizer the greater the WSI values Nemeth et al (2010) reported that increasing the glycerol content in TPS films increased the dry matter content soluble in water The LRP refers to the amount of plasticizer that reaches out of the biofilm in an aqueous medium to find the equilibrium resulting in 70 of PRL in biofilms TPSG- 40 (Table 1) However the TPS-M biofilms have less PRL having greater capacity plasticizer permanence in the polymer matrix This is attributed to that agave syrup containing compounds of higher molecular weight (polymer-oligomers and monosaccharides) compared with glycerin (lower molecular weight) that interact with the starch generate less free space that allow exists less migration plasticizer to the surface of the polymer matrix (Casas-Gonzalez 2012) releasing only the low molecular weight compounds containing agave nectar and maintaining prebiotic FOS inulin and dextrans in the polymer matrix

Vol 1 Pag10

Dynamic mechanical analysis (DMA)

The rheological properties of TPSG TPSGE and TPS-M TPS-ME biofilms are shown in Figure 1 G values of TPSG and TPSGE biofilms showed two transitions the first one at about -75degC corresponding to plasticizer-rich domains and the second at around 45ordmC assigned to starch-rich domains (Rodriguez-Gonzalez F J et al 2004 Da Roz Carvalho Gandini and Curvelo 2006 Khanh et al 2015) Conversely most of TPSM and TPSME biofilms showed just one transition at around 50degC which could be associated to starch-rich domains as observed in Figure 1b (Rodriguez-Gonzalez F J et al 2004)

Figure 1 Effect of glycerin content (a) and agave syrup (b) on the storage module TPS biofilms

Some authors have related the maximum of loss modulus (log Grdquo) to the glass transition temperature (Tg) of biofilms The analysis of Grdquo confirmed that TPSG and TPSGE biofilms have two thermal transitions and that both are dependent of glycerol content As reported in the literature the thermal transitions dropped as glycerol content increased However the first transition seemed to be less dependent on both the glycerol content and the process for preparing TPS biofilms than the second one (Fig 2) Unexpectedly Grdquo values of TPSM and TPSME biofilms evidenced the presence of two thermal transitions In the case of TPS-M biofilms the first thermal transition increased from -40deg to -28degC as the concentration of agave syrup decreased from 40 to 30

Figure 2 Effect of glycerin content (a) and agave syrup (b) on the loss module TPS biofilms

Vol 1 Pag11

The extrusion method is a good alternative for obtaining TPS-M biofilms as it provides a better mixing effect and distribution of plasticizer in biofilm formation The biofilms TPS-GE starch-rich domains have more defined compared to TPS-G biofilms Agave syrup has a greater effect of permanence within the polymer matrix to obtain lower loss of plasticizer that migrates to the surface while maintaining the high molecular weight compounds bonded to the biofilm (prebiotics) and releasing only low molecular weight sugars The Tg of plasticized biofilms agave syrup increases with increasing concentration of plasticizer and decreases to be obtained by the extrusion method

REFERENCES AndersonRAConwayHFPeplin skiAJ(1970)Gelatinization of corn grits by roll cooking extrusioncooking and steaming Starch 22 130ndash135Bastioli Catia (2001) Global status of the production of biobased materialsStarch - Staumlrke 53(8)351-355

Casas-Gonzaacutelez MR Rodriacuteguez-Gonzaacutelez FJ Contreras-Esquivel JC Andrade-Ramiacuterez G (2014) Estudio del efecto plastificante de la miel de agave y glicerina en la obtencioacuten de biopeliacuteculas de almidoacuten termoplaacutestico Memorias del 37 Congreso Internacional de Metalurgia y Materiales ISSN2007-9540 147-156

Casas-Gonzaacutelez MR (2012) Caracterizacioacuten molecular de biopoliacutemeros de aguamiel (Agave salmiana) Tesis Doctoral Facultad de Ciencias Quiacutemicas Universidad Autoacutenoma de Coahuila

Da Roacutez A Carvalho A J F Gandini A amp Curvelo A A S (2006) The effect of plasticizers on thermoplastic starch compositions obtained by melt processing Carbohydrate Polymers 63(3) 417ndash424

Fakhouri F M Costa D Yamashita F Martelli S M Jesus R C Alganer K amp Innocentini-MeiL H (2013) Comparative study of processing methods for starchgelatin films Carbohydrate polymers95(2) 681-689

Fang JM et al (2004)The chemical modification of a range of starches under aqueous reaction conditions Carbohydrate Polymers 55 p 283ndash289

Khanh Minh Dang Rangrong Yoksan (2015) Development of thermoplastic starch blown film by incorporating plasticized chitosan Carbohydr Polym 115 575-581

Li M Liu P Zou W Yu L Xie F Pu H amp Chen L (2011) Extrusion processing and characterization of edible starch films with different amylose contents Journal of Food Engineering 106(1) 95- 101

Mali S Sakanaka L S Yamashita F amp Grossmann M V E (2005) Water sorption and mechanical properties of cassava starch films and their relation to plasticizing effect Carbohydrate Polymers 60 283e289

Maran J P Sivakumar V Sridhar R amp Immanuel V P (2013) Development of model for mechanical properties of tapioca starch based edible films Industrial Crops and Products 42 159-168

Vol 1 Pag12

Mathew A P amp Dufresne A (2002) Plasticized waxy maize starch effect of polyols and relative humidity on material properties Biomacromolecules 3(5) 1101-1108

Nemet N T Soso V M amp Lazi_c V L (2010) Effect of glycerol content and pH value of film- forming solution on the functional properties of protein-based edible films Acta Periodica Technologica (41) 1e203

Rodriacuteguez-Castellanos W Martiacutenez-Bustos F and Jimeacutenez-Areacutevalo O (2013) Functional properties of extruded and tubular films of sorghum starch-based glicerol and Yucca Schidigera extract Industrial Crops and Products 44 405-412

Rodriguez-Gonzalez F J Ramsay B A amp Favis B D (2004) Rheological and thermal properties of thermoplastic starch with high glycerol content Carbohydrate Polymers 58(2) 139-147

Tena-Salcido C F Rodriacuteguez-Gonzaacutelez et al (2008) Effect of Morphology on the Biodegradation of Thermoplastic Starch in LDPETPS Blends Polymer Bulletin 60(5) 677-688

Van der Burgt M C Van der Woude M E amp Janssen L P B M (1996) The influence of plasticizer on extruded thermoplastic starch Journal of Vinyl and Additive Technology 2(2) 170-174

Vol 1 Pag13

AROMATIC QUANTIFICATION USING SS NMR SPECTROSCOPY FOR SOY-BASED FILLERS

Paula Watt Toshikazu Miyoshi Coleen Pugh

Department of Polymer Science The University of Akron cpughuakronedu

INTRODUCTION

Lighter weight composites are desirable for many markets including automotive aerospace and consumer goods Glass-reinforced thermoset molding compounds use mineral fillers to reduce cost by displacing the more expensive resin matrix Because these fillers are a significant portion of the compound and have typical densities of 25 gcc the density of the composite is greater than that of an unfilled system Renewable biomass fillers have a density similar to that of the matrix resin yielding compounds at the same volume reinforcement of glass with a 20-25 weight reduction while maintaining the cost savings provided by matrix displacement Thermal treatments of the biomass improve the hydrophobicity of the fillers although cure inhibition problems can be induced [1] This inhibition is attributed to aromatic species that form during the heat treatment [2] Controlled thermal processing of soy biomass can yield fillers that do not interfere with the compound cure [3] Quantification of filler characteristics to measure the level of thermal treatment are needed for quality assurance and process development In previous studies elemental analysis (EA) was used to characterize the extent of treatment [2] and solid state NMR (SS NMR) spectroscopy was used as a semi-quantitative means to measure the aromatic content of heat-treated biomass [4] This paper correlates the SS NMR characterization of heat-treated soy fillers to EA results

EXPERIMENTAL

A BRUKER AVANCE III 300 MHz NMR spectrometer was used to obtain solid-state 13C high speed magic-angle spinning (CPMAS) NMR spectra of filler samples at a resonance frequency of 756 MHz A double resonance probe at 13000 Hz spinning speed with a 2 ms cross-polarization contact time and a pulse repetition rate of 2 s was employed Figure 1 compares the 13C SS NMR spectra of soy hulls treated at increasingly high temperatures (from top to bottom) to that of untreated soy hulls (UTSH) the 204 degC and 249 degC samples were treated in a batch pilot process the 288 degC and one 400 degC sample were treated in a continuous pilot process and the other 400 degC was treated in a muffle oven [2] All samples were dried under vacuum at 25 degC for two days and sealed for storage prior to testing

00E+00

20E+08

40E+08

60E+08

80E+08

10E+09

12E+09

050100150200

204 degC ECP

249 degC ECP

288 degC AGTNCSU bench

400 degC Muffle furnace

400 degC AGTNCSU pilot

Figure 1 13C SS NMR spectra of untreated (UTSH) and heat treated soy hull fillers

Vol 1 Pag14

RESULTS AND DISCUSSION

As demonstrated in Figures 1 and 2 the resonances at 55 to 115 ppm corresponding to cellulose decrease and are eliminated with increasing heat treatment while a broad aromatic resonance develops in the 95 to 160 ppm range The aliphatic resonances in the region from 10 to 45 ppm including those from the protein content first increase relative to the cellulose resonances with treatment and then diminish at the most aggressive treatment level The carboxyl resonances at 165 to 185 ppm also diminish with increasing treatment

The resonances were integrated for the carboxyl aromatic cellulose and aliphatic content Due to the high signal-to-noise ratio of the lower intensity resonances the spectra were smoothed using a 10-point running average before the baseline was corrected and integrated The cellulose resonances were integrated without smoothing to avoid distortion since the random noise fluctuation had a minimal effect on their calculated values The calculated integrals are plotted in Figure 2 as a function of heat treatment

Figure 2 Composition of untreated (UTSH) and heat-treated soy fillers calculated by 13C SS NMR spectroscopy

Figure 3 presents the expanded baseline-corrected region for the cellulose resonances As the intensity of the heat treatment increases the cellulose resonances diminish and disappear entirely for the two most aggressive treatments

Figure 3 Baseline-adjusted 13C SS NMR spectra of the cellulose region of soy fillers

UTSH 204 degC ECP 249 degC ECP288 degC

AGTNCSUbench

400 degCMufflefurnace

400 degCAGTNCSU

Pilotcellulose 897 858 698 410 00 00aliphatic 43 58 120 194 238 69carboxyl 60 49 43 39 20 15aromatic 00 35 140 356 742 915

00100200300400500600700800900

-50E+07

00E+00

50E+07

10E+08

15E+08

20E+08

25E+08

30E+08

35E+08

456585105

204 degC ECP

249 degC ECP

Vol 1 Pag15

Figure 4 presents the changes in the aliphatic region of the untreated and heat-treated soy hulls The aliphatic content increases as less stable oxygenated species are liberated The profile shift seen in the 400 degC muffle furnace sample indicates that the amount of CH3 chain ends increase relative to the CH2 groups as a result of thermally induced chain scission In the most aggressively treated sample the aliphatic content decreased significantly as ring formation of the aliphatic structures occurs

Figure 4 Baseline-adjusted aliphatic region of the 13C SS NMR spectra of untreated and heat-treated soy fillers

As shown in Figure 5 the carboxyl resonance decreases with increasing heat treatment although some carbonyl species persist even in the most aggressively treated sample The decrease in carbonyl content between the 204 degC and 249 degC treated ECP samples corresponds to accelerated carboxyl liberation in that range

Figure 5 Baseline-adjusted carboxyl region of the 13C SS NMR spectra of untreated and heat-treated soy fillers

Finally Figure 6 presents the increase in aromatic content as the heat treatments intensified The fillers treated at up to 288 degC did not inhibit cure The 400 degC treated filler with much higher aromatic content resulted in significant inhibition and a reduction in properties

Figure 6 Baseline-adjusted aromatic region of the 13C SS NMR spectra of soy fillers

-500E+06000E+00500E+06100E+07150E+07200E+07250E+07300E+07350E+07

0102030405060

204 degC ECP

249 degC ECP

-500E+07

000E+00

500E+07

100E+08

150E+08

95115135155175

204 degC ECP

249 degC ECP

400 degC AGTNCSU pilotppm

Vol 1 Pag16

Figure 7 plots the aromatic content derived from the 13C SS NMR data as a function of the ratio of the moles of hydrogen plus oxygen and carbon from the EA data for the same sample set [4] This figure confirms that the aromatic content correlates with the loss of oxygen and hydrogen ie as the heat treatment becomes more aggressive the oxygen and hydrogens in the biomass are liberated and aromatic rings form

ACKNOWLEDGEMENTS We authors are thankful for funding by USB New Uses Grant 2456 amp 1340-512-5275 under sub-contract from Premix Inc

y = -43642x + 11255Rsup2 = 0986

00 05 10 15 20 25 30

(H+O)C

Vol 1 Pag17

Figure 7 Correlation of 13C SS NMR spectral data to EA data for the aromatic content of heat-treated soy hulls

CONCLUSIONS

Both elemental analysis and 13C SS NMR spectroscopy can be used to measure the level of aromatic formation in biomass as a result of its heat treatment With a correlation coefficient of 099 the data corresponding to the aromatic content of the soy hulls are in excellent agreement The data from these characterization methods can assist in the development of optimal heat treatments as well as provide a quality assurance measure of batch-to-batch repeatability

REFERENCES [1]

Lee R ldquoReactions of Polyester Resins and the Effects of Lignin Fillersrdquo Composite Technology Inc 2001 httpmaterialchemistrycomDreamHCDownloadPolyester20Reactionspdf downloaded 30 August 2016

Watt P Pugh C Studies to Determine Critical Characteristics of Thermally Treated Biomass Fillers Suitable for Thermoset Composites Polymers from Renewable Resources 2015 6 1-24

Watt P Pugh C Rust D Soy-Based Fillers for Thermoset Composites Robert Brentin Soy-Based Chemicals and Materials ACS Symposium Book Series American Chemical Society Washington DC 2014 265-298Sharma R Wooten J Baliag V Lin X Chan W Hjaligol R Characterization of Chars from

Pyrolysis of Lignin Fuel 2004 83 1469-1482

PREPARATION AND CHARACTERIZATION OF ELECTRICALLY CONDUCTIVE POLYMER NANOCOMPOSITES WITH DIFFERENT

CARBON NANOPARTICLES

Viacutector Cruz-Delgado1 Edson Pentildea-Cervantes1 Joseacute Perales-Rangel1 Marcelina Saacutenchez-Adame1 Fabiaacuten Chaacutevez-Espinoza1 Joseacute Mata-Padilla1 Juan Martiacutenez-

Colunga1 Carlos Aacutevila-Orta1 1Centro de Investigacioacuten en Quiacutemica Aplicada Blvd Enrique Reyna Hermosillo No 140 Col San

Joseacute de los Cerritos Saltillo Coahuila 25294 Meacutexico victorcruzciqaedumx

Abstract Polymer nanocomposites offer great expectations for new and unexpected applications due the possibility to change their behavior by the addition of nanoparticles meanwhile retaining the flexibility and processability of plastics [12] Carbon nanoparticles possess a combination of high electrical and thermal transport low density and different morphology that makes it a good choice to reinforce plastics [3] The possibility of electrical and thermal conduction in a polymer matrix with low amounts of the nanoparticles brings opportunity for high demanding applications such as electrical conductors and heat exchangers [45] In this work different carbon nanoparticles like carbon nanotubes (CNT) modified carbon nanotubes (CNTM) graphene (G) and carbon black (CB) were selected to reinforce high density polyethylene (HDPE) at contents of 20 wtwt by mean of ultrasound-assist extrusion [6] to obtain electrically conductive nanocomposites

Keywords Carbon nanoparticles electrically conductive compounds polymer nanocomposites

Experimental Materials High-density polyethylene (HDPE) with a MFI = 20 g10 min injection grade was used as polymer matrix Carbon nanotubes (CNT) with an average OD = 30 nm length 10 ndash 30 micron purity ge 90wt and SSA ge 110 m2g COOH functionalized CNT (CNTM) with an average OD = 20 nm length 10 ndash 30 micron purity ge 90wt and SSA ge 200 m2g and graphene nanoplatelets (G) with an average thickness = 8 nm 8-10 layers average length lt 2 micron and SSA ge 500 m2g were purchased to Cheap Tubes Inc USA and were industrial grade Carbon black Vulcan XC-72 average particle size = 15 nm SSA ge 600 m2g purity ge 95 was acquired from Cabot USA Carbon nanoparticles were used without further purification

Methodology A twin-screw extruder LD 401 Thermo Scientific 24-MC was used to process all the samples with a plain temperature profile of 220 degC and 100 rpm Resin chips and powder were feed to the extruder with the assistance of gravimetric feeders for each one at a rate of 5 and 1 kgh respectively The samples were extruded with the assistance of ultrasound waves [6] drive by a home made generator of variable amplitude and frequency in the range of 20 ndash 50 kHz and power of 500 W

Vol 1 Pag18

Characterization Thermogravimetric analysis were carried out in a TGA TA Instruments model Q500 at a heating rate of 10 degCmin with a flow of N2 of 50 mlmin Electrical properties (permittivity and resistivity) were measured with a high precision LCR meter Keysight model E4980A in the frequency range of 20 Hz to 1 MHz 4 specimens were tested and the average value was reported Tensile testing was conducted using a Universal Testing Machine INSTRON 4301 model at 5 mmmin using type V specimens in accordance with ASTM D 638 standard method For the flexural properties evaluation 2 X 05 inches strips were employed in accordance with ASTM D 790 standard method

Results Carbon nanoparticles prevent the thermal degradation of polyethylene resin at different extent as we can see in Figure 1 Nanocomposites with carbon black could enhance the thermal degradation resistance by up to 93 ordmC and 36 ordmC at the 5 and 50 respectively Nanocomposites with CNT CNTM and G shown a similar tendency which suggest that carbon nanoparticles are an effective filler to prevent the thermal degradation at elevated temperatures or during the processing by the common polymer processing methods

Figure 1 Thermal degradation temperature for nanocomposites with different carbon nanoparticles

Mechanical properties of polymer nanocomposites are shown in Figure 2 The flexural modulus of polymer nanocomposites exhibits an average increase up to 100 respect of PE resin in this case graphene is the best reinforcing nanoparticle this result could obey the 2D geometry of planar sheets of graphene that are homogeneously dispersed in the polyethylene matrix Nanocomposites with CNT CNTM and Carbon black shown similar values for flexural modulus despite of presence of ndashCOOH functional groups grafted on the surface of CNTM or the semi-spherical morphology of CB nanoparticles The tensile stress is not increased notoriously with the addition of carbon nanoparticles nevertheless for nanocomposites with CNTM the tensile stress is the lowest and suggest that the presence of ndashCOOH functional groups in CNTM are no beneficial for the mechanical reinforcement

Vol 1 Pag19

Figure 2 Mechanical properties for nanocomposites with different carbon nanoparticles

With the addition of carbon nanoparticles is possible to change the permittivity of a polymer and enhance their capacitive behavior which means that this material could retain and release electrical charge during an event The dielectric constant of nanocomposites with different carbon nanoparticles is shown in Figure 3 Polyethylene resin exhibit a value of 3 and this value are linear over the entire range of frequency Graphene nanocomposites shows a value of 10 and a linear response with the frequency Nanocomposites with CNT CNTM and CB exhibit an increase by 3 orders of magnitude respect of polyethylene resin and their response is dependent the frequency showing lower values at high frequencies4

Figure 3 Dielectric constant as a function of frequency for nanocomposites with different carbon nanoparticles

Polyethylene is considered the best electrical insulator nevertheless with the addition of carbon nanoparticles this behavior was changed as shown in Figure 4 Polyethylene resin exhibit high resistance values at low frequencies as the frequency increase polarization effects are present and diminishes their insulated behavior Graphene nanocomposites shown a similar tendency like polyethylene resin which corresponds with the lower values of permittivity observed above Nanocomposites with CNT and CNTM exhibit a reduction up to 7 orders of magnitude in resistivity against polyethylene resin and a linear response

Vol 1 Pag20

Surprisingly nanocomposites with CB show the lowest resistivity value around 1 Ωm and a lineal response over the entire range of frequency This value of electrical resistivity is close to electrical conductor and suggests their use in high demand applications like electrolytic and PEM fuel cells and passive electronic components

Figure 4 Electrical resistivity as a function of frequency for nanocomposites with different carbon nanoparticles

Conclusions The thermal degradation of the nanocomposites has shown an increase up to 93 ordmC and 36 ordmC at 5 and 50 of degradation respect of the HDPE resin Mechanical properties shown an average increase of 100 in flexural moduli nevertheless tensile stress shown a little increase Finally permittivity measurements as a function of frequency in the range of 20 Hz ndash 1 MHz shown high values for nanocomposites in the following order CB CNTM CNT andG which are in agree with the low values of resistivity Due the good balance of propertiesfor this polymer nanocomposites they will be used in the electronicelectric sector and forthermal conduction applications

References

[1] Prog Polym Sci 2010 35 357

[2] Prog Polym Sci 2010 35 1350

[3] Polymer 2015 55 642

[5] Polymer 2002 43 2279

[6] J Polym Sci Part B Polym Phys 2015 53 475

Acknowledgements We acknowledge the financial support from Fondo SENERCONACYT under CeMIE-Sol program Project 20745012 This work was financially (partially) supported by CONACYT through Project 250848 Laboratorio Nacional de Materiales Grafeacutenicos for their support with the characterization of materials and to Francisco Zendejo Gilberto Hurtado and Rodrigo Cedillo for their assistance with processing and characterization of polymer nanocomposites

Vol 1 Pag21

Impact of process variables on the recovery of starch extracted from jicama

Gonzaacutelez-Lemus LB 1 Calderoacuten-Domiacutenguez G 1 Farrera- Rebollo RR 1 Guumlemes-Vera N 2 Chanona-Peacuterez JJ 1 Salgado- Cruz MP1 Martiacutenez-Martiacutenez V1

1ENCB-IPN Departamento de Ingenieriacutea Bioquiacutemica Prolongacioacuten de Carpio y Plan de Ayala SN Casco de Santo Tomas CP 11340 Meacutexico D F Meacutexico E-mail e-luck_10hotmailcom

2ICAp-UAEH Av Universidad km 1 Rancho Universitario Tulancingo Hidalgo CP 43600 Meacutexico

Abstract Jicama (Pachyrizus erosus) is a native crop from Mexico and Central America and part of the genus Pachyrhizus which includes other species such as jacatupeacute and ahipa Previous studies show that this tuber is low in protein inulin and fructo-oligosaccharides but has large amounts of starch However the values reported for this crop are variable and can be the result of the type used growing conditions or the extraction method applied On the other hand it has not been found reports that mention or evaluate the percentage of extraction of jicama starch so the objective of this work was to study the effect of different process conditions at the same time (freezing sonication and soaking in sodium metabisulfite) in the yield percentage of starch through response surfaces A Box-benhken design was used with three variables and three levels and five central repetitions with a total of 17 trials The experimental design was significantly adjusted a quadratic model (P = 00183) with a coefficient of determination (R2 = 08745) and 07131 adjusted R When evaluating variables applied to designing both the freezing time as sonication significantly affected the response (P lt005) as well as the interaction between the time of freezing and sonication (P = 00256) while soaking time had no significant effect (P = 009184)

Figure 1 Effect of hydration time freezing and sonication on the extraction of starch from jicama

As for the combined and based on statistical analysis methods it was observed that the starch yield is increased with respect to time of sonication or freezing but independently finding an antagonistic effect by combining the two or three variables while the soak time had no significant effect It is necessary to focus future research combining ultrasound and or other mechanical process variable which can be conducted to study its effect on the performance and properties of starch from various sources

Vol 1 Pag22

Introduction

The legumes are plants of great importance worldwide mainly because of its seeds which are rich in proteins which are the second most important crop after cereals However some legumes have tuberous roots such as potatoes (Solanum tuberosum) jicama (Dioscorea rotundata) and cassava (Manihot utilissima)[1] On the other hand jicama (Pachyrizus erosus) is a native crop from Mexico and Central America and part of the genus Pachyrhizus which includes other species such as jacatupeacute and ahipa This legume is considered that the only edible part is the root which resembles a turnip [2] In Mexico the main producers are Nayarit (56995 tons) Morelos (26134 tons) and Guanajuato (8789 tons) (SIAP 2014) Most industrial starches are extracted from cereals and tuberous roots but still jicama starch has not yet been exploited for industrial applications [3] Previous studies show that this tuber is low in protein inulin and fructo-oligosaccharides but has large amounts of starch but the values reported for this crop are variable and can be the result of the type used growing conditions or the extraction method applied [4] However it has not been found reports that mention or evaluate the percentage of extraction of jicama starch so the objective of this work was to study the effect of different process conditions at the same time (freezing sonication and soaking in sodium metabisulfite) in the yield percentage of starch through response surfaces design

Methods Results and Discussion

To perform the isolation of jicama starch was left of the methodology proposed by Novelo-Cen and Betancur-Ancona (2005) Jicama was peeled and cut into cubes of about 1cm on each side and were processed by grinding using a sodium bisulfite solution (1500 ppm) in a 1 3 tuber solution respectively After soaking time the suspension was placed in bags by sealing and subjecting the product to freezing and thawing Once the suspension was completely thawed jicama and environmental conditions it was placed in an ultrasonic bath (40W) for the required time Then the bagasse fiber is filtered through fine mesh making three washes with distilled water to achieve recover as much starch and remove impurities The solution was allowed to precipitate for 2 hours and decanted cooling resulting starch extracted in the background Finally the starch paste was dried in a convection oven for 12 hours at 45 deg C The process extraction is carried out by a Box-benhken design using Design Expert v9 software with three variables and three levels and five central repetitions with a total of 17 trials (table 1)

Table 1 Intervals of operating conditions used in this test (soak time sonication time and freeze time)

Treatment Freezing (days)

Sonication (minutes)

Hydratation (minutes)

1 0 60 15 2 0 30 30 3 0 0 15 4 1 0 30 5 1 30 15 6 1 60 30 7 2 30 0 8 1 30 15 9 1 60 0

Vol 1 Pag23

10 1 30 15 11 2 60 15 12 2 0 15 13 1 30 15 14 2 30 30 15 1 0 0 16 0 30 0 17 1 30 15

The response variable was the starch yield percentage expressed on dry basis The experimental design was significantly adjusted a quadratic model (P = 00183) with a coefficient of determination (R2 = 08745) and 07131 Adjusted R This results show that both the freezing time as sonication significantly affected the response (P lt005) as well as the interaction between the time of freezing and sonication (P = 00256) while soaking time had no significant effect on the recovery starch (P = 009184) (see Figure 1)

Conclusions As for the combined and based on statistical analysis methods it was observed that the starch yield could be increased with respect to time of sonication or freezing but independently finding an antagonistic effect by combining the two variables while the soak time had no significant effect Depending on the results the freeze-thaw step can be eliminated as it represents greater time and cost of processes leaving only the sonication and soaking bisulfite It is necessary to focus future research combining ultrasound and or other mechanical process variable which can be conducted to study its effect on the performance and physical rheological and functional properties of starch from tubers roots but independently

References [1] Melo E A Stamford T L M Silva M P C Krieger N Stamford N (2003) Functional propertiesof yam bean (Pachyrhizus erosus) starch J Bioresource Technology 89 103ndash106[2]Ramos de la Pentildea A Ring G Noel TR Perker R Cairns P Findlay K y Shewry P R (2002)Characterization of starch from Tubers of Yam Bean (Pachyrhizus ahipa) J Agric Food Chem 50361-367[3] Stevenson D Janeb J y Ingletta G (2007) Characterisation of Jiacutecama (Mexican Potato)(Pachyrhizus erosus L Urban) Starch from Taproots Grown in USA and Mexico Starch 59 132-140[4] Zhu F (2015) Composition structure physicochemical properties and modifications of cassavastarch Carbohydrate Polymers 456-480

Acknowledgements Thanks for financial support to the project IPN-SIP 20151383 and IPN Mexico COFAA

Vol 1 Pag24

CHARACTERIZATION OF CARBOHYDRATE-PROTEIN GELS USINGDSC AND CONFOCAL MICROSCOPY

Hernaacutendez-Espinosa N Salazar-Montoya JA y Ramos Ramiacuterez EG

Department of Biotechnology and Bioengineering CINVESTAV-IPN Mexico City 073600 MEXICO

E-mail eramoscinvestavmx

SUMMARY

During the last decade it has increased the interest in exploring the gelling of aqueoussolutions with a mix of carbohydrates and proteins due to the functional properties of thesebiopolymers as food additives The characterization of these mixtures is necessary for thedevelopment of new processing methods due to their ability to formation of structures withimproved functional properties It has been reported that gliadin (prolamin wheat) is capableof gelling at alkaline pH and temperature of 50 ˚C Therefore this work aimed to study theformation of gels from low methoxyl pectin (LMP) and gliadin to characterize its thermalproperties and observe its distribution in the gels Dispersions were prepared to LMP at 1 and 05 of gliadin the latter stained with fast green following the methodology proposed byBeaulieu 2001 Gel formation was induced by the addition of CaCl2 Differential ScanningCalorimetry (DSC) was performed weighing 8 mg of gel and heated from 20-350 degC with aramp 10 degC Structure of the gels was performed using Confocal Microscopy Laser Leicaequipment (diode type) and software Leica Application The images were obtained with a 63xlens LMP was able to form gels in presence of divalent ions Ca2+ gelling mechanism isdescribed as egg box model Confocal Microscopy showed gliadin dispersed in the gel withuniform distribution Calorimetric studies showed a single peak near to 210 degC and ∆H= 1573Jmol having a different behavior with respect to the controls The results showed that it ispossible to design carbohydrate-protein gels with potential properties of interest which couldbe useful in the industry of light foods enriched with wheat proteins

Key words Low Methoxyl Pectin (LMP) Gliadin Confocal Microscopy Differential ScanningCalorimetry (DSC)

INTRODUCTION

The gliadins are a source of protein storage in the wheat gluten and are essential for formationthey determine its viscous nature In combination with glutenin they provide significantviscoelastic properties to bread dough The low methoxyl pectins (LMP) are obtain bymodification of high methoxyl pectins (HMP) by controlled desterification reaction commonlycarried out by a chemical method LMPs have the ability to form gels without the presence ofsugar being an important advantage in the formulation of low calorie foods [5]Carbohydrates-proteins complex arise from electrostatic interactions between oppositelycharged macromolecules These interactions induce the formation of different supramolecularentities such as aggregation and complex coacervates [1] The nature of complexcarbohydrate-protein is determined by factors that affect the entropy of the system likestructure and molecular weight of the components Gelation of these macromolecularcomplexes generally takes place by formation of new bonds between the two biopolymers

Vol 1 Pag25

polycation-polyanion electrostatic interactions and gel formation due to mutual exclusion ofeach component [4]In these systems favorable interactions occur between anionic polysaccharides and proteinsfound below their isoelectric point which can cause increases the gelation temperaturemelting temperature and gel strength among others [4]The concentrated dissolutions of two biopolymers (protein-protein carbohydrate-protein orpolysaccharide-polysaccharide) may be turbid and gradually separated into two translucentlayers each of which may contain some of the other component However before phaseseparation compounds gels are obtained where the gelling biopolymer constitute a continuousphase network and the second is limited to form inclusions in the discontinuous phase [3]Systems formed by various gelling agents can form gels fillers mixed and complex [6] In thisresearch were proposed two techniques confocal microscopy and differential scanningcalorimetry for the characterization of carbohydrate-protein gels

METHODOLOGY

LMP dispersions gliadin 1 and 05 were prepared the latter with Fast Green FCF trade stained adapting the methodology proposed by Beaulieu [2] Gel formation was induced by theaddition of CaCl2 The analysis by Differential Scanning Calorimetry (DSC) was performedweighing 8 mg gel heated from 20 to 350 degC with a ramp 10 degC The structure of the gels wasanalyzed by using a computer Confocal Microscopy (Leica TCS laser (diode type) and LeicaApplication Software Ver 241) The images were obtained with a 63x lens and scannedbetween 640 and 700 nm

RESULTS

Confocal MicroscopyThe gels were prepared with varying thickness (le 140 microns) by placing them between a slide and coverslip after obtaining the serial sections for better structure observation of thegels and take gel micrographs Using of Leica Application Software (Ver 241) was possibleto analyze the structure of experimental gels (LMP-gliadin)Figures 1 to 4 show the front and side face of a gel obtained by LMP and gliadin Red dots(Figures 2 and 4) represent the fluorescence emitted by the chromophore bound to the proteincan also be seen that the protein is embedded in the three-dimensional gel network anddistributed homogeneously (Figures 1 and 3) Figures in black and white (Figures 2 and 4) area repeat of his counterpart in another format of design and red dots to gliadin immersed in thegel formed by the carbohydrate (black dots)

DSC (Differential Scanning Calorimetry)As a result of the comparative determination of the thermal properties of carbohydrate-proteingel and individual components (LMP and gliadin) in Figure 5 is showing the thermogramcorresponding gel LMP-gliadin which showed a different behavior of the presented controls(data not shown)The main peak suggests that it is a homogeneous mixture obtained undersuitable processing conditions The thermal peak was obtained near 210 degC and it wasrequired a change energy (∆H= 1573 Jg)

Vol 1 Pag26

Figures 1 and 2 Front view of LMP-gliadin gel

Figures 3 and 4 Side view of LMP-gliadin gel

Figure 5 Thermogram corresponding to LMP-gliadin gel

Vol 1 Pag27

CONCLUSIONS

With the proposed methodology it was achieved to obtain gels containing LMP-gliadin Theproteins were uniformly distributed in the three-dimensional polysaccharide network (LMP)The use of a chromophoric compound can permit to observe the morphology of thecarbohydrate-protein gel by Confocal Microscopy Also by the use of DSC analysis we candeterminate the changes in the thermal behavior of a mixed gel

ACKNOWLEDGEMENTS

To CONACYT for the financial support number 211425 to NHE For their technical support toBiol M P Meacutendez Castrejoacuten from Biotechnology and Bioengineering Department and to MScI J Galvaacuten Mendoza from LaNSE -CINVESTAV (Confocal microscopy)

REFERENCES

[1] Antonov Y A Zhuravleva I L Macromolecular complexes of BSA with gelatinInternational Journal of Biological Macromolecules (2012) 51 (3) 319-328[2] Beaulieu M Turgeon S L Doublier J L Rheology texture and microstructure of wheyproteinslow methoxyl pectins mixed gels with added calcium International Dairy Journal(2001) 11961-967[3] Chronakis I S Kasapis S Abeysekera R Structural properties of gelatin-pectin gelsPart I Effect of ethylene glycol Food Hydrocolloids (1997) 11 271-279[4] Hua Y Gelling property of soy proteinndashgum mixtures Food Hydrocolloids (2003) 17 889-894[5] Sriamornsak Pornsak Chemestry of pectin and its pharmaceutical uses a review Libre enla red[6] Zasypkin D V Braudo E E Tolstoguzov V B Multicomponent biopolymer gels FoodHydrocolloids (1997) 11 159-170

Vol 1 Pag28

STUDY OF THE CHARGE INTO THE PHYSICOCHEMICAL PROPERTIES OF A COMPOSITE MATERIAL

Karina Abigail Hernaacutendez-Hernaacutendez Javier Illescas Mariacutea del Carmen Diacuteaz-Nava Claudia Muro-Urista

Instituto Tecnoloacutegico de Toluca Av Tecnoloacutegico SN Col Agriacutecola Bellavista CP 52169 Metepec Estado de Meacutexico Meacutexico jillescasmittolucaedumx

Introduction

The development of the adsorbent materials for water treatment is one of the most important research goals in the environmental field within these materials are the polymer clay composites consisting of a polymeric matrix material in which the disperse phase particles are clay the physicochemical properties of the material will be influenced according to the different loads or dispersed clay content The materials were synthesized in aqueous solution noting that the ratio of acrylic acidwater and the crosslinking agent also play an important role in the structure and strength of materials The synthesized materials were characterized by swelling limit tests critical pH and pH reversibility also thermogravimetric analysis and infrared spectra were obtained

Experimental

Composites were prepared according to the procedure used in the literature1 In a test tube known quantities of acrylic acid monomer (AAc 2 3 or 4 g) and benzoyl peroxide radical initiator (BPO) 1 wt- referred to that of the monomer were put together and mixed by means of an ultrasonic bath until the initiator was dissolved Then a certain amount of water was added to the mixture to give a total mass of 6 g and triethylene glycol dimethacrylate (TEGDMA) crosslinker agent was added 04 wt- referred to the amount of AAc monomer and placed in an ultrasonic bath for 5 minutes until its complete dissolution Next solutions were placed in an oil bath for polymerization and the temperature was increased gradually from 318 to 338 K to avoid an autoacceleration process and an excessive bubbling in the polymer The temperature program was 318 K for one hour 323 K for two hours 328 K for three hours 333 K for 4 hours and 338 K for 24 hours After cooling to room temperature the synthesized polymers were washed in deionized water for a week to remove unreacted reagents Finally they were cut into small disks of 2 mm length (Fig 1) and dried at room temperature for two days and put into a vacuum oven at 343 K for one week or until constant weight of the samples was reached

Figure 1 Polymer clay composites of (a) AAcH2O(21)Clay 5 wt-

(b) AAcH2O(11)Clay 5 wt- and (c) AAcH

2O(12)Clay 5 wt-

Vol 1 Pag29

Results and discussion

According to the Table 1 of swelling percentage materials reach their equilibrium swelling around 8 h with 400-500 water uptake It is noteworthy that the sample containing 12 AAcH2O (ww) had 1600 of water uptake However this sample was the one with the poorest mechanical properties

Table 1 Swelling percentage of the polymer clay composites

Time (min)

Swelling () PAAcH2O (21)Clay

PAAcH2O (11)Clay

PAAcH2O (12)Clay

PAAcH2O (21)

PAAcH2O (11)

PAAcH2O (12)

0 0 0 0 0 0 000 5 5414 3424 6115 4210 4723 5000

10 6934 6373 7806 5365 6902 6758 20 10276 11288 12590 7477 8642 9848 30 12320 14644 15036 8831 10612 12727 60 22707 21627 24532 12629 15870 19227 90 30580 26746 28201 15631 20497 24576

120 34834 32203 32014 18619 24704 30076 180 41796 38610 39460 23147 31453 39318 240 42652 44271 46223 25976 35698 47364 360 43867 51627 51475 30066 42620 60712 480 44116 56610 54748 32390 46654 72121

1440 45829 69017 63993 36521 55449 124091 2880 46298 71627 66367 37397 58107 158485

TEGDMA was used in these samples as crosslinking agent which gives better cohesion properties for the changes at different pH and increase the swelling percentage for all samples (with different AAcH2O proportions) Figure 2 shows the pH critical value was found around 52 for materials without clay and 55 for materials with dispersed clay material

Figure 2 pH critical value of the polymer clay composites in aqueous solution

Vol 1 Pag30

Figure 3 presents the reversibility of the extended and collapsed states for the composites PAAc and PAAcclay at pH values above and below the critical pH value Measurements were made for 8 h at pH = 22 and then for 8 h at pH = 7

Figure 3 Reversibility at different pH values of the polymer clay composites in aqueous solution

Spectra of PAAc hydrogel clay and PAAcclay composite with 5 wt- content PAAc hydrogel shows in the carbonyl stretching region the characteristic stretching absorption band of the carbonyl group C=O appeared at 1700 cm-1 The stretching of C=O coupled with the bending OH neighboring carboxyl groups is responsible for the bands occurring at 1164 and 1241cm-1 and the bands corresponding to CH2 at 2961 and 1477cm-1

Figure 4 shows the thermograms of the compounds synthesized in aqueous solution where a weight loss is observed from 513 to 573 K In the next stage PAAc dehydration occurs between 573 to 713 K Then the decarboxylation of PAAc at 500 degC and finally in the last stage around 823 K polymer degradation begins Clay-containing composites were more stable since they started to lose weight at around 513 K while the PAAc begins at 473 K Finally in the composite of PAAcH2O (21) with 5 wt- clay-content weight losses were minor compared with the other two materials

Figure 4 Thermogravimetric analysis of the AAcH2OPolymer Clay composite

Vol 1 Pag31

Conclusions

From these set of results it can be said that both the clay filler and the crosslinking agent play an important role into the mechanical properties of the materials As expected they responded to pH variations and the critical pH value was found between 52 and 55 depending on the clay content This property of PAAc could find an eventual application in liquid effluents with different pH values Also the synthesized materials showed excellent reversible response to cyclical changes in pH In addition materials with a little dispersed clay content had better structural properties than those without the mineral structure

References [1] NM Ranjha and UF Qureshi Int J Pharm Pharm Sci 2014 6 400-410[2] R Srinivasan Advances in Materials Science and Engineering 2011 17 pages[3] SS Ray y M Okamoto Progress in Polymer Science 2003 28 1539-1641[4] E I Unuabonah E I et al Appl Clay Sci 2014 99 83-92

Acknowledgments Karina Abigail Hernaacutendez-Hernaacutendez is grateful to CONACyT for scholarship No 573583 We are also thankful to CONACyT for project 3056 ldquoCaacutetedras-CONACyTrdquo and to Tecnoloacutegico Nacional de Meacutexico (TecNM) for project 564615-P for their financial support

Vol 1 Pag32

CHARACTERIZATION OF CHITOSAN MEMBRANES PROPERTIES AS A POTENTIAL MATERIAL FOR POLYCYCLIC AROMATIC

HYDROCARBONS (PAHs) REMOVAL IN WATER

A Ozaeta-Galindo1 B Rocha Gutieacuterrez1 F I Torres Rojo1 G Zaragoza Galaacuten1O Soliacutes Canto2 C Soto Figueroa1 D Y Rodriacuteguez Hernaacutendez1 L Manjarrez

Nevaacuterez1

1Facultad de Ciencias Quiacutemicas Universidad Autoacutenoma de Chihuahua Av Escorza 9000 col Centro CP 31000 Chihuahua Chih Meacutexico lmanjarrezuachmx

2Centro de Investigacioacuten en Materiales Avanzados (CIMAV SC) Chihuahua Chih Meacutexico

I Introduction

Human health and the environment have been threatened because of the exposure to synthetic chemicals Some are classified as persistent organic pollutants (POPs) They are resistant to photolytic chemical and biological degradation Some of them include a wide range of substances such as organochlorine pesticides and their metabolites industrial chemicals and by-products [1]

Polycyclic aromatic hydrocarbons (PAHs) are the most common subclasses of POPs They constitute a large group of organic compounds with two or more fused aromatic (benzene) rings which may be presented in the environment by an incomplete combustion at high temperature of organic matter or by processing of fossil fuels [2] These compounds have carcinogenic mutagenic and teratogenic properties Additionally PAHs are persistent in the environment due their chemical stability and biodegradation resistance [3] For these reasons it is very important to implement efficient technology for their removal

The membrane processes are found at the highest vanguard level of separation technology due to its efficiency Materials are ones of the most important parameters for achieving at high percent of removal pollutant Among various available film materials considerable attention has been given to biopolymers of their surface properties and biodegradability Chitosan is a polysaccharide which is derived from chitin and is available from waste products in the shellfish industry Its chemical mechanical and antibacterial properties have been applied in removal applications The functional properties of chitosan films are improved when chitosan is combined with other materials [4]

On the other hand adsorbents are extensively used to remove contaminants including PAHs from wastewater Activated carbon (AC) is a good adsorbent material especially for non-polar compounds PAHs adsorption on AC mainly depends on their textural properties

Vol 1 Pag33

and oxygen functional groups at the periphery of carbon layers which may be involved in adsorption mechanisms [5]

The present work was directed to synthesize composite membranes of chitosan activated carbon and to obtain their morphologic and hydrophilic properties for their potential use in the removal PAHs from waste water

II Metodology

Membrane synthesis

Chitosan solutions (2 wv) were prepared by dispersing chitosan (sigma Aldrich low molecular weight) in acetic solution (1 vv) Composite film base chitosan was prepared without activated carbon or 05 10 and with 15 of activated carbon provided from NORIT (Hidrodarcoreg R) by casting method The casting solutions were spread over a glass dish Precipitation by solvent evaporation was carried out at 60degC in an environmental chamber (Labnet I5211-DS) during 18 h Then the samples were immersed in sodium hydroxide solution bath in order to be removed from dish washing thoroughly with pure water and finally were dried at 25degC for 48h before stored

Morphology Characterization

Chitosan and composites films morphology were analyzed by atomic force microscopy (AFM) in a Multimode Nanoscope IVa Veeco Instrument Images were obtained in a tapping mode Determination of root means square roughness was carried out with the WSxM software Hydrophilic properties were attained by contact angle analysis through the sessile drop method using an FTA-32 goniometer Firsttenangstrom

III Results

Roughness and surface hydrophilicity are the main parameters to control the membrane fouling and permeability characteristics Incorporation of nanomaterials can also change the porosity and pore size of membranes and subsequently modify their water permeability and solute rejection

Figure 1 shows the AFM micrographics of chitosan composite films with 05 10 and 15 activated carbon loads The surface roughness (Rms) of chitosan film has been altered by activated carbon addition Chitosan film presents the lower Rms value in relation with composites membrane (269 nm and 9 nm respectively) The increase of surface roughness of chitosanAC in comparison to chitosan films is probably because of the low spread AC particles into polymeric matrix as a result of their different polarity However this roughness modification will allow improving the low flux of chitosan film as consequence of its dense structure because it will increase the contact area in the removal process Furthermore Salehi et al 2012 reports that polar-no polar interaction between hydrophilic groups of chitosan and hydrophobic aromatic ring of carbon nanotubes causes formation of channels like wrinkles in the polymer matrix improving permeability through membrane [6]

Vol 1 Pag34

According AFM images the synthesis film process and chitosan-AC interaction cause the AC disposition on the top surface membrane and by this hydrophobic character required for PAHs adsorption affinity Therefore this has been confirmed by contact angle results where chitosan matrix increased its contact angle from 76deg to 89deg in accordance with the increasing AC loading from 0 at 15 (wv) in the organic phase

The changes of membrane structure physicochemical property and mechanical resistance due to the presence of fillers materials rely on the good dispersion of filler in polymeric matrix as well as good compatibility between them [7] Efficient dispersion and homogeneity in chitosan film of AC particles was observed at relatively low loading (1) providing more accessible active sites for sorption of organic pollutants on the surface film

Figure 1 Topography images obtained by AFM of chitosan membranes (a) and composite chitosanactivated carbon membranes at different loads (b) 05 ( c) 10 and (d) 15

IV Conclusion

Incorporation of activated carbon at low loading (1 wv) in chitosan films modifies the morphology and surface properties of this material in such a way that can be used in the PAHs removal from wastewater

Vol 1 Pag35

V References

[1] Loos et al EU-wide survey of polar organic persistent pollutants in European river waters Environ Pollut (2009) 157 561-568[2] Samanta S K et al Polycyclic aromatic hydrocarbons environmental pollution and bioremediation Trends Biotechnol (2002) 20 243-248[3] Rubio-Clemente et al Removal of polycyclic aromatic hydrocarbons in aqueous environment by chemical treatments a review Sci Total Environ (2014) 478 201-225[4] Salehi et al A review on chitosan-based adsorptive membranes Carbohydr Polym (2016)152

419-432[5] Gong Zongqiang et al Activated carbon adsorption of PAHs from vegetable oil used in soilremediation J Hazard Mater (2007) 143372-378[6] Salehi E et al Novel chitosanpoly (vinyl) alcohol thin adsorptive membranes modified with aminofunctionalized multi-walled carbon nanotubes for Cu (II) removal from water preparationcharacterization adsorption kinetics and thermodynamics Sep Purif Technol (2012) 89 309-319[7] Salehi E el al A review on chitosan-based adsorptive membranes Carbohydr Polym (2016)152419-32

Acknowledgements The authors acknowledge the support of Universidad Autoacutenoma de Chihuahua (UACH) Centro de Investigacioacuten en Materiales Avanzados (CIMAV) Laboratorio de nanotecnologiacutea and Oacutescar Soliacutes Canto for technical support in sample analysis

Vol 1 Pag36

ARTIFICIAL WEATHERING OF POLYETHYLENEMULTIWALL CARBON NANOTUBES AND POLYETHYLENECOPPER

NANOPARTICLES COMPOSITES PREPARED BY MEANS OF ULTRASOUND ASSISTED MELT EXTRUSION PROCESS

Juan G Martiacutenez-Colunga1 Lina Septien1 Mariacutea C Gonzalez-Cantuacute1 Juan F Zendejo-Rodriguez1 Marcelina Sanchez-Adame1 Manuel Mata1 Viacutector J

Cruz-Delgado1 Carlos A Aacutevila-Orta1 1Centro de Investigacioacuten en Quiacutemica Aplicada Blvd Enrique Reyna Hermosillo No 140 Col San

Joseacute de los Cerritos Saltillo Coahuila 25294 Meacutexico Guillermomartinezciqaedumx

High density Polyethylene (HDPE) composites with high loadings of Multiwall Carbon Nanotubes (MWCNTs) and Cupper (Cu) nanoparticles were fabricated through ultrasound assisted melt extrusion technology The present work shows the artificial weathering behavior of these polyethylene composites as a function of MWCNTs and Cu nanoparticles type with different contents (1 25 and 5 w) It was observed that the nanoparticle content has a significant effect on the nanocomposites elongation at break mainly at higher particle contents Nanocomposites were exposure to UV radiation into a QUV chamber for 1000 hr The degraded samples were characterized by tensile properties It was observed that the tensile strength and elongation at break of pristine HDPE decrease as a function of UV exposure time It was established that MWCNTs composites had a better behavior during exposure to UV radiation than Cu composites This was confirmed because the tensile properties of MWCNT composites did not show any significant changes after 1000 hours of exposure

Keywords High density polyethylene carbon and cupper nanoparticles composites artificial weathering

Introduction Copper (Cu) nanoparticles as well as multiple wall carbon nanotubes (MWCNTs) provide a very favorable mechanical polymer reinforcement as well as an increase in the electrical and thermal conductivity [1-4] But one of the problems in melt mixing is to obtain a good dispersion and homogenization of the nanoparticles in the polymer matrix To solve this problem ultrasound was used to assist the extrusion process Due to its properties nanocomposites are being used every day in a wide variety of applications and some of them are outdoors [4-6] For this reason the present study aims to find the research work is to submit to artificial weathering for nanocomposites with nanoparticles of Cu and MWCNTs into HDPE

Experimental Materials High-density polyethylene (HDPE) with a MFI = 20 g10 min Alathon H620 was used for obtain the masterbatch High density polyethylene (HDPE) with a MFI 008 g10 min Total HP401N was used for dilutions Cu nanoparticles used have an average particle size 300nm hemispherical morphology purity 995 SSA 6 m2g supplier SkySpring Nanomaterials Inc USA Multi-walled carbon nanotube (MWCNTs) was supplied by the

Vol 1 Pag37

Alpha Nano Tech Co Ltd Incheon Korea Their diamater was 30ndash50 nm and 5ndash15 micron in length

Methodology Masterbatch preparation A twin-screw extruder LD 401 Thermo Scientific 24-MC was employed to process a masterbatches (HDPEMWCNTs and HDPECu) with a plain temperature profile of 230 degC and 100 rpm Resin chips and powder of nanoparticles (MWCNTs or Cu) were feed to the extruder with the assistance of gravimetric feeders for each one at a rate of 5 and 1 kgh respectively The samples were extruded with the assistance of ultrasound waves [6] drive by a home-made generator of variable amplitude and frequency in the range of 20 ndash 50 kHz and power of 500 W Nanocomposites dilutions preparation A twin-screw extruder LD 401 Thermo Scientific 24-MC was employed to process a nanocomposites dilutions with a plain temperature profile of 230 degC and 100 rpm Resin chips of HDPE with a MFI 008 g10 min and chips of masterbatch (HDPEMWCNTs and HDPECu) obtained nanomaterials with concentration of 0 1 25 and 5 of nanoparticles Samples preparation using chips of dilutions are prepared by compression molding test samples for the exposition to UV radiation and to determine tensile properties Artificial weatheringThe weathering accelerated test was carried out using the cycle 1 described in ASTM G 154 (using UVA-340 lamps 8 hours of UV radiation at 60degC and 4 hours of water condensation at 50degC) Samples were taken every 250 hours to accumulate 1000 hours of exposure

Characterization Tensile properties using ASTM D 638 for nanocomposites were measured before and after exposure into a QUV chamber in order to determine the changes of properties due to polymer degradation by the action of accelerated aging conditions

Results Tests conducted in the HDPE without particles gave base determine the behavior of the material in terms of its tensile strength and elongation at break Therefore we have a point of comparison to know if MWCNTs and Cu nanoparticles provide an improvement to the material

0 200 400 600 800 1000

Exposure time (hr)

0 conc 1 conc 25 conc 5 conc

HDPECu

Vol 1 Pag38

Figure 1 Tensile strength of the nanocomposites HDPECu with different concentration of Cu nanoparticles

The behavior of the tensile strength of the nanocompounds of Cu and MWCNTs as a function of the exposure time in accelerated artificial weathering are show in the Figures 1 and 2 The best behavior for HDPECu was found at 1 concentration followed by 25 and 5 But the nanocomposite containing 1 shows the largest decrease in the tensile properties for a longer exposure time It is also observed as the nanocomposite containing 5 copper no significant changes by exposure to UV radiation

Figure 2 Tensile strength of the nanocomposites HDPEMWCNTs with different concentration of nanotubes

In nanocomposites with MWCNTs the tensile strength showed the best behavior concentration 1 followed by 25 to 5 Minor changes occurred in tensile behavior at any concentration and time of UV exposure

In the nanocomposite with particles of Cu is observed that the elongation at break present at 1 concentration such behavior HDPE without nanoparticles But the highest concentrations of Cu nanocomposites retained for longer exposure this elongation up to 750 hours Nano composites that presented the lowest variation of the elongation at break as a function of exposure time were the ones with 5 concentration

0 200 400 600 800 1000

Exposure time (hr)

HDPEMWCNTs

Vol 1 Pag39

Figure 3 Elongation at break of nanocomposites HDPECu with different concentration of Cu nanoparticles

In nanocomposites with MWCNTs it is observed that the elongation at break is significantly affected by the concentration of MWCNTs The exposure time had no significant effect in the elongation at break on these nanocomposites

Figure 4 Elongation at break of nanocomposites HDPEMWCNTs with different concentration of nanotubes

Conclusions Cu nanoparticles strengthens HDPE at low concentrations and provide some protection to UV radiation at high concentrations The MWCNTs exhibits excellent UV protection to HDPE contractions from 1

0 200 400 600 800 1000

Exposure time (hr)

0 conc 1 conc 25 conc 5 concHDPECu

0 200 400 600 800 1000

Exposure time (hr)

0 conc 1 conc 25 conc 5 concHDPEMWCNTs

Vol 1 Pag40

References

Masoumeh NS et al J Comp Mat July 29 2015 0021998315597556

Shuklaa AK et al 84 2013 Pages 58ndash66

[1] Comp Sci Tech 2007 67 3071

[2] J Appl Polym Sci 2004 91 2781

[3] Mat Charac 2013 84 58

[4] Comp Part B Eng 2013 55 407

[5] J Polym Sci part B 2012 50 963

[6] Polym Degr Stab 2013 98 2411

Acknowledgements We acknowledge the financial support from Fondo SENERCONACYT under CeMIE-Sol program Project 20745012 This work was financially (partially) supported by CONACYT through Project 250848 Laboratorio Nacional de Materiales Grafeacutenicos The funding for the trip for exposure this paper in the Polymat 2015 was supported by REDINMAPLAS We thank its support with the characterization of materials and to Francisco Zendejo Gilberto Hurtado and Rodrigo Cedillo for their assistance with processing and characterization of polymer nanocomposites

Vol 1 Pag41

THERMAL MECHANICAL AND ELECTRICAL BEHAVIOR OF POLYPROPYLENEMULTIWALL CARBON NANOTUBES POLYPROPYLENEGRAPHENE AND POLYPROPYLENECARBON

BLACK COMPOSITES PREPARED BY MEANS OF ULTRASOUND ASSISTED MELT EXTRUSION PROCESS

Joseacute M Mata-Padilla 1 Viacutector J Cruz-Delgado 1 Janett A Valdez-Garza 1 Edson Jesuacutes L Flores-Maacuterquez 1 Gilberto F Hurtado-Loacutepez 1 Jesuacutes G Rodriacuteguez Velaacutezquez 1 Carlos A

Aacutevila-Orta 1 Juan G Martiacutenez-Colunga1 1 Centro de Investigacioacuten en Quiacutemica Aplicada Blvd Ing Enrique Reyna H 140 Col San Joseacute

de los Cerritos Saltillo Coahuila Meacutexico CP 25294 Email josemataciqaedumx

The Thermal Mechanical and Electrical behavior of Isotactic polypropylene (iPP) composites with high loadings of Multiwall Carbon Nanotubes (MWCNTs) graphene (G) and carbon black (CB) was studied by means of Melt Flow Index (MFI) Differential Scanning Calorimetry (DSC) Thermogravimetric Analyzer (TGA) tensile and flexural analysis and surface conductivity and dielectric constant as a function of current frequency The MFI of neat polypropylene decreased for all cases with the addition of each carbon nanoparticles Additionally the thermal properties indicated a nucleating effect on the iPP matrix where any nanoparticle was introduced being the maximum effect for graphene nanoparticles Conversely the tensile properties showed a not significant change in the composites respect to the neat iPP while the flexural module increased about three times with all carbon particles It was also found that dielectric constant and surface conductivity behavior was a function of type of carbon nanoparticle and in some cases of the current frequency

Introduction The scientific and thecnological interest of polymer nanocomposites with carbon nanoparticles has increased in recent years due to the outstanding thermal [1] mechanical [2] and electrical [3] performance of these composites In the case of polypropylenenanocomposites there are reports about the fabrication of PPMWCNT nanocompositeswith low electrical percolation threshold and significantly enhanced mechanical properties[4] and PPG nanocomposites with high thermal stability and enhanced mechanicalproperties [5] Nonetheless the high performance of these nanocomposites is highlydependent of an effective dispersion of carbon nanoparticles in the polymer matrix Toadress and solve this problem the melt extrusion process assisted by ultrasoundtechnology has been recently developed [6 7] In the particular case of our researchgroup an ultrasound under variable frequency and amplitude technology has beenreported as a efficient alternative to disperse high loadings of carbon nanoparticles [8 9]However the dispersion of carbon nanoparticles in polypropylene depends of differentfactors such as the nanoparticle type and the processing of nanocomposite (ultrasoundfrequence range extrusion conditions etc) In the particular case of present work themain aim was to study the thermal mechanical and electric behavior of PP

Vol 1 Pag42

nanocomposites with high content of carbon nanoparticles varying the type of nanoparticle (MWCNT G and CB) using constant extrusion and ultrasound conditions

Experimental Polypropylene (Formolene 4111T from FORMOSA Plastics USA MFI= 35 g10min) nanocomposites with high loading of MWCNTs (Cheaptubes USA LD= 100) Graphene (Cheaptubes USA Thickness = 8 nm) and CB (VULCAN VXC-72 Cabot USA size = 15 nm) were prepared by means of melt extrusion process (210degC 100 RPM) assisted by variable ultrasound (15-50 KHz) The extruder was a twin screw extruder LD 401 from Thermo Scientific 24-MC The thermal characterization of PP nanocomposites was realized by DSC (Q200 TA Instrument 10 degCmin N2 Atmosphere) and TGA (Q500 TA Instrument 10 degCmin N2 Atmosphere) The mechanical properties were evaluated in an INSTRON 4301 in accordance with ASTM D 638 (tensile properties) and ASTM D 790 (flexural properties) In addition the electric properties (conductivity and capacitance) were evaluated using a High precision LCR meter Keysight model E4980A in the frequency range of 20 Hz to 1 MHz

Results and Discusion The first effect originated by the incorporation of high loadings of MWCNT G and CB were observed on the melt flow index (MFI) of composites The results of MFI were 450 g10 min for the neat PP 55 g10min for PPMWCNT 102 for PPG and 162 for PPCB samples respectively These results indicated the high influence of carbon nanoparticles on the fluidity properties in accordance with previous works reported for similar systems [9] The thermal properties (TGA and DSC) are reported in the Table 1 These results show that the carbon nanoparticles significantly increased the thermal stability of polymer matrix in about 15 degC at the 50 of degradation for the three carbon nanoparticles similar to previously reported results [3 5] Additionally it was observed an outstanding increase in the crystallization temperature for all nanocomposites which has not been previously reported at high loadings of nanoparticles [4 5] However there were not signifficant changes in the melting behavior of PP (Tm and ΔHm) when the carbon nanoparticles were incorporated

Table 1 TGA and DSC results of Polypropylene Nanocomposites with high loadings of MWCNT G and CB

Sample Td 5 Td 50 Tm (degC) Tc (degC) ΔHm (Jg) ΔHc (Jg)

Neat PP 3735 4376 1684 1109 941 973

PPMWCNT 4201 4520 1686 1310 1043 988

Vol 1 Pag43

PPG 4023 4451 1680 1350 930 909

PPCB 4302 4553 1692 1256 902 888

The effect of high loadings of MWCNT G and CB on the tensile and flexural properties of polypropylene is shown in Table 2 These results clearly indicated that the effect of nanoparticles incorporation was significant in the case of flexural modulus respect to the neat polymer (about 300 ) This behavior has not been previously reported for similar nanocomposites systems [4 5] However the increase in the tensile modulus was limitated

Table 2 Mechanical properties (Tensile and flexural modulus) of Polypropylene Nanocomposites with high loadings of MWCNT G and CB

Sample Tensile Modulus

(MPa) Flexural Modulus

Neat PP 349 2886

PPMWCNT 430 8616

PPG 421 9803

PPCB 442 9130

The results of electric properties are displayed in Figure 1 The Figure 1a shows that the incorporation of high loadings MWCNT and G increased the electrical conductivity of polypropylene about 75 orders of magnitude in all the range of frequency which was superior to similar systems obtained previously by means of solution mixing [3] While when the CB nanoparticles were incorporated the PPCB nanocomposite changed its behavior from static dissipative to semiconductor material [3 9]

Vol 1 Pag44

Figure 1 Electric behavior (a) electric conductivity and (b) dielectric constant of PP nanocomposites with MWCNT G and CB

Conversely the Figure 1b shows an increase in the dielectric constant for the PPMWCNT PPG and PPCB nanocomposites respect to the neat PP sample being higher the case of PPG sample (about 3 order of magnitude) This behavior has been associated to the percolation phenomena [10] The dielectric constant was practically constant in all the range of frequencies

Conclusions This study showed that the introduction of carbon nanoparticles had a high influence on the thermal stability and thermal dissipation of the polypropylene matrix perhaps due to the better dispersion and distribution of nanoparticles in PP matrix when the ultrasound technology was applied It was also observed that PPG and PPMWCNT nanocomposites showed the best flexural and electrical behavior due to a better interfacial interaction while the electrical behavior of PPCB nanocomposites was highly influenced by the current frequency in the range of static dissipative or semiconductor material

References [1] M Norkhairunnisa A Azizan M Mariatti H Ismail and LC Sim J Compos Mater 2012 46 903-910[2] M El Achaby F E Arrakhiz S Vaudreuil A el K Qaiss M Bousmina O Fassi-Fehri Polym Compos 2012

33 733ndash744[3] C A Aacute vila-Orta C E Raudry-Loacutepez M V Daacutevila-Rodriacuteguez Y A Aguirre-Figueroa V J Cruz-Delgado M G

Neira-Velaacutezquez F J Medelliacuten-Rodriacuteguez and B S Hsiao Int J Polym Mater Polym Biomater 2013 62635ndash641

[4] E Logakis E Pollatos Ch Pandis V Peoglos I Zuburtikudis CG Delides A Vatalis M Gjoka E SyskakisK Viras P Pissis Compos Sci Technol 2010 70 328ndash335

[5] P Song Z Cao Y Cai L Zhao Z Fang S Fu Polymer 2011 52 4001-4010[6] AI Isayev R Kumar T M Lewis Polymer 2009 5 250ndash260[7] J M Mata-Padilla C A Aacutevila-Orta F J Medelliacuten-Rodriacuteguez E Hernaacutendez-Hernaacutendez R M Jimeacutenez-

Barrera Viacutector J Cruz-Delgado J Valdeacutez-Garza S G Soliacutes-Rosales A Torres-Martiacutenez M Lozano-EstradaEnrique Diacuteaz-Barriga Castro J Polym Sci Part B Polym Phys 2015 53 475ndash491

Vol 1 Pag45

[8] CA Aacutevila-Orta JG Martiacutenez-Colunga D Bueno-Baqueacutes CE Raudry-Loacutepez VJ Cruz-Delgado P Gonzaacutelez-Morones JA Valdeacutez-Garza ME Esparza-Juaacuterez CJ Espinoza-Gonzaacutelez JA Rodriacuteguez-Gonzaacutelez Mx PatentMXa2009003842 2014

[9] C A Aacutevila-Orta Z V Quintildeones-Jurado M A Waldo-Mendoza E A Rivera-Paz V J Cruz-Delgado J MMata-Padilla P Gonzaacutelez-Morones and R F Ziolo Materials 2015 8 7900ndash7912

[10] A B Espinoza-Martiacutenez Carlos A Aacutevila-Orta V J Cruz-Delgado F J Medelliacuten-Rodriacuteguez Dariacuteo Bueno-Baqueacutes J M Mata-Padilla J Appl Polym Sci 2015 132 41765

Acknowledgements We acknowledge the financial support of this work from the SENERCONACyT fund under CeMIE-Sol program Project 12 ldquoDesarrollo de Captadores Sistemas Solares y Sistemas de Baja Temperatura con Materiales Novedosos para Meacutexicordquo This work was financially (partially) supported by Consejo Nacional de Ciencia y Tecnologiacutea (CONACYT) through Project 250848 we thank its support for the electrical characterization

Vol 1 Pag46

EFFECT OF LaPO4 REINFORCEMENT ON STRUCTURAL THERMAL

AND OPTICAL PROPERTIES OF PMMA

D Palma Ramiacuterez1 M A Domiacutenguez-Crespo1 A M Torres-Huerta1 D DelAngel-Loacutepez1

1 Instituto Politeacutecnico Nacional (IPN) Centro de Investigacioacuten en Ciencia Aplicada y Tecnologiacutea Avanzada CICATA-IPN Unidad Altamira Carretera Tampico-Puerto Industrial CP 89600 Altamira

Tamaulipas Meacutexico mdominguezcipnmx and atorreshipnmx

Abstract In this work precipitation synthesis is used for obtaining lanthanum phosphate (LaPO4) particles and evaluate the possible application as UV absorber to increase the optical properties of poly(methyl methacrylate) (PMMA) In order to reach this goal LaPO4 were dispersed during the polymerization of methyl methacrylate (MMA) and in commercial PMMA Results indicate that LaPO4 can be potentially used to maintain the structural properties when PMMA is used in outdoor applications

Introduction

PMMA exhibits good toughness at high and low temperatures and is one of the most commonly used thermoplastic polymers in outdoor applications As a result of its amorphous structure it allows 92 of light passes through it and therefore it is optically transparent [1] PMMA has the disadvantage to be degraded under solar UV radiation (200-400 nm) this process starts with visible color changes and further leads to cracking and hazing [1] In order to reduce those drawbacks organic or inorganics UV absorbers such as titanium dioxide (TiO2) zinc oxide (ZnO) and cerium oxide (CeO2) can be incorporated [2] Recently rare earth phosphates have been proposed as UV absorber In these systems the UV light is absorbed and dissipated into a longer wavelength where the polymer degradation cannot takes place [3] Lanthanum phosphate (LaPO4) has high temperature stability and chemical inertness [4] and it has not been well explored The main of this work is to disperse LaPO4 into a commercial and synthesized PMMA and evaluate the structural optical and thermal properties of the blends

Experimental

LaPO4 particles were prepared by precipitation method using 0036 M of lanthanum nitrate (LaNO3) and 0036 M of tripolyphosphoric acid (H5P3O10) 50 mL of LaNO3 were added dropwise to 25 mL of H5P3O10 solution under stirring H5P3O10 was previously prepared from the ion exchange of sodium tripolyphosphate (Na5P3O10) Deionized water was added to adjust a final volume of 100 mL and then precipitate was washed with deionized water centrifuged and dried at 100 degC LaPO4 particles were heat treated at different temperatures for 4 h LaPO4 particles were analyzed by Fourier Transform Infrared spectroscopy (FTIR spectrum one Perkin Elmer spectrometer) X-ray diffraction (XRD D8 Advance Bruker diffractometer) dynamic light scattering (DLS ZEN5600 Malver Zetasizer NanoZSP) and fluorescence intensity measurements (LSM 700 Carl ZEISS Microscope)

Vol 1 Pag47

Dispersion of particles into commercial PMMA 01 05 and 1 wt of LaPO4 particles were dissolved in 25 mL of chloroform with 3 g of PMMA pellets (Plexiglas V825) under sonication (2510 Branson) for 30 min

In situ polymerization of particle dispersions in MMA 01 05 and 1 wt of LaPO4 particles were dissolved in 25 mL of chloroform under sonication for 30 min 15 mL of methyl methacrylate and 05 mol wt of benzoyl peroxide were added and stirred for 15 h at 80 degC by mechanical stirring Final solutions were cast in poly(propylene) molds and introduced in an oven for 24 hours at 80 degC Polymers were characterized by FTIR and differential scanning calorimetry (DSC Pyris 1 Perkin Elmer)

FTIR spectra of LaPO4 presented in Figure 1 show the characteristics bands of PO4 groups The absorption bands at 1233-990 and 951 cm-1 are due to P-O stretching in the ν3 vibrationregion in the monoclinic LaPO4 [5] Similarly the bands located at 617 577 and 563 cm-1 areattributed to bending of O=P-O and O-P-O of the PO4

3- groups in the ν4 vibration region [6]XRD patterns in Figure 2 show the progress of the sintering process from room temperature to 700 degC It can be seen that monoclinic structure of LaPO4 (PDF 01-083-0651) is obtained by this facile method at room temperature Additionally high temperature heat treatment only produces the increase in peak intensities

1500 1350 1200 1050 900 750 6000

102030405060708090

100110120

Wavenumber (cm-1)

9511233-990

20 30 40 50 60 70

LaPO4 700 degC

LaPO4 600 degC

LaPO4 500 degC

LaPO4 400 degC

2(deg)

) (103

22) (1

23) (4

0 1000 2000 3000 4000 50000

40LaPO4

Dz = 2300 nm PDI = 12

Diameter (nm)

Figure 1 FTIR spectra of LaPO4

Figure 2 XRD patterns of the high temperature heat treatment of LaPO4

Figure 3 Particle size distribution of LaPO4

The particle size distribution (hydrodynamic diameter) measured from DLS is shown in Figure 3 It is observed that the particles display monodispersity (Polydispersity index (PDI) equal to 12) and an approximate size of about 25 microm This fact clearly confirms that the precipitation method produces larger sizes than the microwave assisted hydrothermal method used to obtain rare earth phosphates [7] However the size is similar to those obtained from the precipitation of LaNO3 and orthophosphoric acid [8] The luminescence spectra were acquired in order to evaluate whether the proposed LaPO4 powders were responsive to UV light Figure 4 presents the emission spectra of LaPO4 samples It is quite evident that this material has luminescent properties since it displays the emission in the visible range of the electromagnetic spectrum specifically in the 450-650 nm

Vol 1 Pag48

range Therefore this feature can help to maintain the structural properties of polymers which are used outdoors and subjected to the UV light

400 450 500 550 600 650 7000

Emission wavelength (nm)

) LaPO4

2000 1800 1600 1400 1200 1000 800

Commercial PMMA1 wt of LaPO4

C-O-CCH3

Wavelength (cm-1)

Commercial PMMA CH

C-O group

2000 1800 1600 1400 1200 1000 800

Synthesized PMMA1 wt of LaPO4

Synthesized PMMA CH

CH3CH3CH

Wavenumber (cm-1)

C-O group

Figure 4 Emission spectra under 405 nm excitation

Figure 5 FTIR spectra of selected commercial PMMA PMMALaPO4

Figure 6 UV-Visible spectra of selected synthesized PMMA and PMMALaPO4

The addition of the LaPO4 either into commercial PMMA (Figure 5) or synthesized PMMA (Figure 6) does not generate new bands or shifting of bands in the FTIR bands spectra Therefore the spectra display the characteristic bands of PMMA as follows 1723 cm-1 stretching of C=O 1443 cm-1 is the CH of CH3O group 1210-1320 cm-1 to the O-C stretchingvibration 1135 cm-1 is the C-O stretching 1382 cm-1 and 750 cm-1 are the α-methyl group 3440 cm-1 985 cm-1 is the C-O-CH3 rocking 960-650 cm-1 is bending of CH [9]The effect of the incorporation of LaPO4 on the optical properties of PMMA was also observed by UV-Visible spectroscopy Figure 7 and 8 display the transmittance in the UV-visible range for LaPO4 dispersion into commercial PMMA and synthesized PMMA respectively It can be seen that PMMA and PMMALaPO4 samples show UV absorption in the 180-400 nm range in all samples Even they are almost transparent to the visible light it is important to mention that there was no control of the thickness of the polymer Therefore the transmittance percentage cannot be associated to the different wt addition of LaPO4 The unique differences between commercial and synthesized PMMA is observed in the UV region πminusπ transition in the excited states of carbonyl group in PMMA is observed in commercial PMMA blends and not in synthesized PMMA [10] This interesting feature might be probably due to the interaction between the carbonyl group and LaPO4

200 300 400 500 600 700

Wavelength (nm)

Commercial PMMA

Commercial PMMA01 wt LaPO4

200 300 400 500 600 700

Wavelength (nm)

Synthesized PMMASynthesized PMMA01 wt LaPO4

Synthesized PMMA05 wt LaPO4Synthesized PMMA1 wt LaPO4

LaPO4 content (wt)

Tgrsquos commercial PMMA (degC)

Tgrsquos synthesized PMMA (degC)

0 65 108 01 86 110 05 98 112 1 99 115

Table 1 Tgrsquos temperatures

Figure 7 UV-Visible spectra of commercial PMMA and PMMALaPO4

Figure 8 UV-Visible spectra of synthesized PMMA and PMMALaPO4

Vol 1 Pag49

It is observed that the glass transition temperature (Tg) of synthesized PMMA is higher than commercial PMMA The addition of LaPO4 into commercial and synthesized PMMA increases Tg with increasing the amount of LaPO4 which is indicative of the reduction in mobility [11]

Conclusions

Luminescent LaPO4 particles of micrometer scale with monazite phase can be obtained by facile precipitation method at room temperature XRD analysis confirmed that further thermal treatments do not alter the monoclinic structure The addition of the particles into PMMA improves the thermal stability by increasing the Tg which can be of advantage for applications that require higher temperatures Emission properties of LaPO4 corroborate that this systems can be potentially used as polymer fillers to maintain the structural properties and improve the thermal stability of the polymers

References

[1] Rudko G Kovalchuk A Fediv V Chen WM Buyanova IA Nanoscale Res Lett 2015 10 81[2] Wiley Processing and finishing of polymeric materials Volume 2 John Wiley amp Sons HobokenNew Jersey 2012 p 718[3] Palma-Ramiacuterez D Domiacutenguez-Crespo MA Torres-Huerta AM Ramiacuterez-Meneses ERodriacuteguez E Dorantes-Rosales H and Cayetano-Castro H Ceram Int 2016 42(1 Part A) 774-788[4] Wieczorek-Ciurowa K Mechanochemical Synthesis of Metallic-Ceramic Composite Powders inM Sopicka-Lizer (Eds) High-Energy Ball Milling Mechanochemical Processing of NanopowdersWoodhead Publishing Ltd 2010 p 260[5] Li G Li L Li M Song Y Haifeng Z Lianchun Z Xuechun X and Shucai Gan Mater ChemPhys2012 133(1) 263-268[6] Zhou R Lv M and Li X Opt Mater 2016 51 89-93[7] Nguyen Thanh H Nguyen Duc V Dinh Manh T Do Khanh T Nguyen Thanh B Train Kim Aand Le Quoc M Rare Earths 2011 29(12) 1170-1173[8] Sujith SS Arun Kumar SL Mangalaraja RV Peer Mohamed A and Ananthakumar S CeramInt 2014 40 15121-15129[9]Balamurugan A Kannan S Selvaraj V and Rajeswari S Trends Biomater Artif Organs 2004 18(1) 41-45[10] El-Bashir SM Al-Harbi FF Elburaih H Al-Faifi F and Yahia IS Renewable Energy 2016 85928-938[11]Rymma S Filimon M Dannert R Elens P Sanctuary R and Baller J Nanotechnology 201425(42) 425704 (8pp)

Acknowledgements

D Palma-Ramiacuterez is grateful for her postgraduate scholarship to CONACYT SIP-IPN and COFAA-IPN The authors are also grateful for the financial support provided by CONACYT through theCB2009-132660 and CB2009-133618 projects and to IPN through the SIP 2015-0202 2015- 02272015-0205 SIP 2016-0541 SIP 2016-0542 and 2016-0543 projects and SNI-CONACYT

Vol 1 Pag50

LIFETIME PREDICTION AND DEGRADABILITY ON PETPLA AND

PETCHITOSAN BLENDS

D Palma Ramiacuterez1 A M Torres-Huerta1 M A Domiacutenguez-Crespo1 D DelAngel-Loacutepez1

1 Instituto Politeacutecnico Nacional (IPN) Centro de Investigacioacuten en Ciencia Aplicada y Tecnologiacutea

Avanzada CICATA-IPN Unidad Altamira Carretera Tampico-Puerto Industrial CP 89600 Altamira Tamaulipas Meacutexico atorreshipnmx and mdominguezcipnmx

Abstract Artificially accelerated weathering test (1200 h) was carried out in commercial poly(ethylene terephthalate) (PET) and recycled (R-PET) with poly(lactic acid) (PLA) or chitosan blends obtained by the extrusion process Weak interactions between the biodegradable and polyester polymers were found Lifetime prediction indicates that blends made from R- PET will decompose faster than from commercial PET From overall samples R-PET chitosan (955) and R-PETPLA (8515) were found to degrade faster than the otherscompositions after 45 and 54 years respectively

Introduction The most favorable packaging material for soft drink bottles is PET a kind of semi-crystalline thermoplastic polyester with high strength and transparency properties Unfortunately most of these beverage bottles are used only once and then they are discarded which inevitably creates serious resource waste Consequently the environmental problems (white pollution) is becoming more and more serious [1-2] In order to solve this problem one approach is to combine PET with materials preferentially from renewable resources such as chitosan and PLA to obtain a resistant material during their use and have degradable properties at the end of their useful life [3] This implies the study of the structural morphological and degradation properties as well as the lifetime prediction of the final blends In this work efforts have been made to evaluate the properties when selected ratios of poly(lactic acid) (PLA) and chitosan biopolymers are incorporated during the extrusion process into two matrixes virgin PET and recycled PET (R-PET) Comparison between both type of blends and pure PET was made Filaments were obtained and their structural miscibility thermal and morphological properties as well as their degradation under accelerated weathering were investigated to determine the feasibility of these blends

Experimental Different amounts of PLA (2002D NatureWorks) (5 10 and 15 wt-) or chitosan (1 25 and 5 wt-) with commercial PET (CLEARTUFreg-MAX2) or R-PET (from discarded bottles) were hand mixed previous to extrusion process Blends with filaments shape were obtained in a single-screw extruder (CW Brabender) with LD ratio of 251 and four heating zones feeding (225 degC) compression (2375 degC) distribution (260 degC) and the extrusion die (225 degC) PETPLA R-PETPLA PETchitosan and R-PETchitosan blends were subjected to accelerated weathering (aw) test (QUVSe 313 nm and 063 Wm2) under UV (8 h 60 degC)condensation (4 h 50 degC) cycles for a period of 1200 h Weight loss percentage was used to estimate the degradation rate according to Eq (1) where K is a constant of conversion units to mmyear W is the weight loss (g) A is the area exposed (cm2) T is the time (h) and D is the density of the material (g cmminus3) Degradation rate =

ATDEq (1)

Vol 1 Pag51

All blends were analyzed by Fourier Transform Infrared spectroscopy (FTIR spectrum one Perkin Elmer spectrometer) differential scanning calorimetry (DSC) (Labsys Evo Setaram) and scanning electron microscopy (SEM JEOL 6300)

Results and discussion Structural changes FTIR spectra of PETPLA R-PETPLA PETChitosan and R-PETChitosan blends are shown in Figure 1a-f For PETPLA and R-PETPLA the band between 1768 cm-1 and 1670 cm-1 represents the carbonyl group of PET and PLA The spectra show the main characteristics bands of PET as follows at 1619-1510 cm-1 is the aromatic skeleton stretching 1460ndash1341 cm-1 is CH2 deformation 1266ndash1102 cm-1 is C(O)Ostretching 1018 cmminus1 is the 14 aromatic substitution 963 cmminus1 is OCH2 stretching ofethylene glycol 869 cmminus1 is C-H deformation on an aromatic ring and 730 cm-1 is the band associated to the out of plane deformation of the two carbonyl substituents on the aromatic ring [4-7] On the other hand when PET and R-PET is blended with chitosan there is no evidence of chitosan phase in the FTIR spectra due to the lower amounts used in the extrusion process In this blends there were no shift of the bands of any group in PET or R-PET either with PLA or chitosan This confirms the no chemical interaction between both phases

2000 1750 1500 1250 1000 750

PETPLA 955a) PETPLA 9010

PETPLA 8515

C-OCH2

1768-1670

R-PETPLA 955

14 substitutionR-PETPLA 9010

PET signalsC=O PLA

Wavenumber (cm-1)

R-PETPLA 8515C=O PET

3000 2500 2000 1500 1000

PETchitosan 991

PETchitosan 97525

PETchitosan 955

R-PETchitosan 991

R-PETchitosan 97525

Wavenumber (cm-1)

R-PETchitosan 955

C=O PET

2000 1800 1600 1400 1200 1000 800

PET-PLA 955

PET-PLA 8515

PET-PLA 9010

C-O1700 1747 C=O(a)

Wavenumber (cm-1)

2000 1800 1600 1400 1200 1000 800

R-PETPLA 8515

R-PETPLA 9010

R-PETPLA 955

Wavenumber (cm-1)2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715 1700

C=O(c)CH2

2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715

1700C=O(c) CH2

PETchitosan 955

Figure 1 Spectra of a) PETPLA and R-PETPLA blends b) PETchitosan and R-PETchitosan blends c) PETPLA blends after aw test d) R-PETPLA blends after aw test e) PETchitosan blends after aw test and f) R-PETchitosan blends after aw test

The spectra after accelerated weathering test show the structural changes in the bands produced by the temperature UV light and humidity after 1200 h For blends with PLA C=O band is divided into different bands 1700 cm-1 and 1747 cm-1 represent the photo-oxidation of the amorphous and crystalline chains respectively [68] Amorphous band is more defined

Vol 1 Pag52

than crystalline because these regions are more susceptible to be degraded In a similar way PLA C=O band appears at higher wavenumber Also ester bonds at 1318 cm-1 and 1180 cm-1 for PET and PLA and CH2 bands in PET at 1410 cm-1 and 1340 cm-1 becomebroad and weak after the process Blends with chitosan spectra display weak bands showing the typical splitting of C=O signals In blends of R-PETchitosan the shifting of crystalline-amorphous C=O is not observed indicating the degradation Morphological changes The surface morphologies of the exposed filaments of blends are compared in Figure 2 In all micrographs of blends the damage caused by the UV light and humidity is evident PET and R-PETPLA blends are mainly composed of cracks which appear after the beginning of degradation by breaking of the C-O bonds of both polyesters [9] On the other hand PET and R-PETChitosan produces a similar damage but with smaller cracks that are due by the swelling of chitosan powders Degradation rates and lifetime prediction A relationship of 1000 h of accelerated weathering in QUV chamber equal to 1 year of natural weathering was used to evaluate the degradation rate and the lifetime prediction of final blends [10] Figure 3 shows that the blends of R-PETPLA or chitosan degrade faster than PETPLA or chitosan blends this is mainly due to the nature of the PET (recycled bottles) From all samples the lifetime prediction indicates that R-PETchitosan (955) and PLA (8515) will decompose after 45 and 54 years of natural weathering respectively

00 10x10-3 20x10-3 30x10-3 40x10-3

107 years103 years

76 years

91 years

58 years

54 years

143 years93 years

60 years

56 years

55 years

Degradation rate (mmyear)

PETPLA 8515

PETPLA9010

PETPLA 955

R-PETPLA 8515

R-PETPLA9010

R-PETPLA 955

PETchitosan 955

PETchitosan 97525

PETchitosan 991

R-PETchitosan 955

R-PETchitosan 97525

R-PETchitosan 991

45 years

Figure 2 Surface morphologies of exposed surfaces of PET and R-PETPLAPET and R-PETChitosan PETPLA R-PETPLA PETChitosan and blends after accelerated weathering test

Figure 3 Degradation rate of blends under accelerated weathering

Thermal properties Table 1 displays the thermal properties of blends before and after being subjected to accelerated weathering In general PET R-PET PLA PETPLA R-PETPLA PETChitosan and PETChitosan blends showed a decreasing in the melting (Tm) and crystallization (Tc) temperatures The shifting of the Tc and Tm are mainly due to the disentangled and break of the chains Mostly shorter chains that are easily to move at lower temperatures are generated after the degradation [11]

Vol 1 Pag53

Table 1 Thermal properties of as-prepared blends before and after aw test

Conclusions In this study the effect of accelerated weathering on structural properties and lifetime prediction of PET PLA and its blends showed how the degradation rate is improved when PLA or chitosan are added into the conventional matrix Degradation of PETchitosan favors more the scission of the chains compared to the PETPLA blends Thermal properties confirmed the modification of Tm and Tc after the degradation Degradation leads to cracking along the surface exposed The best performance was obtained for PETchitosan polymer blend with a 955 weight ratio where an estimate time of about 45 years is required for its degradation

References [1] Bach C Dauchy X and Chagnon M-C Water Res 2012 46(3) 571-583[2] Zhang Y Guo W Zhang H and Wu C Polym Degrad Stab 2009 94 1135-1141[3] Lucas N Bienaime C Belloy C Queneudec M Silvestre F and Nava-Saucedo J-EChemosphere 2008 73(4) 429-442[4] Garlota D J Polym Environ 2001 9(2) 63-84[5] Zhao Q Jia Z Li X and Ye Z Mater Des 2010 31 4457ndash4460[6] Andanson JM and Kazarian SG Macromol Symp 2008 265 195ndash204[7] Mai F Habibi Y Raquez JM Dubois P Feller JF and T Peijs et al Polymer 2013 54 6818ndash6823[8] Zhang WR Hinder SJ Smith R Lowe C and Watts JF J Coat Technol Res 2011 8 329-342[9] Copinet A Bertrand C Govindin S Coma V and Couturier Y Chemosphere 2004 55 763-773[10] Wagner N and Ramsey B Technical Document by GSE Lining Technology Inc 2003 HoustonTX USA[11] Pasch H and malik M Advanced Separation Techniques for Polyolefins 1st edition SpringerLaboratory Springer International Publishing Switzerland 2014 pp 42-43

Acknowledgements D Palma-Ramiacuterez is grateful for her postgraduate fellowship to CONACYT COFAA and SIP IPN Theauthors are also grateful for the financial support provided by the CONACYT Research Fellowship-IPN-CICATA Altamira agreement 2014-1905 IPN through the SIP 2016-0541 2016-0542 2016-0543and 2016-1158 projects and SNI-CONACYT The authors thank to ROMFER SA CV industries fortheir technical support

Polymer Tm (degC) Tc (degC) Tm (degC) Tc (degC)

As prepared After accelerated weathering

PET 126 243 201 248 170 R-PET 245 205 227 245 156 PLA 161 126 150 120

PETPLA 955 250 200 152 243 205 PETPLA 9010 250 202 152 242 202 PETPLA 8515 250 205 155 244 200 R-PETPLA 955 250 158 198 152 241 194 R-PETPLA 9010 250 201 152 243 180 R-PETPLA 8515 250 158 202 152 239 180 PETChitosan 991 248 197 240 184

PETChitosan 97525 249 197 242 191 PETChitosan 955 251 203 249 190

R-PETChitosan 991 248 208 241 - R-PETChitosan 97525 250 207 - -

R-PETChitosan 955 250 208 240 -

Vol 1 Pag54

EXTRACTION AND CHARACTERIZATION OF FOOD BIOPOLYMERSFROM BYPRODUCTS OF MANGO (Manguifera indica L)

Ramos-Ramirez E G Sierra-Loacutepez D Pascual-Ramiacuterez JSalazar-Montoya J A

Biotechnology and Bioengineering Department CINVESTAV-IPN Av IPN 2508 Col San Pedro

Zacatenco CP 07360 Mexico City Mexico Email eramoscinvestavmx

ABSTRACT

Due to its production volume and consumption rate mango is one of the most important fruitcrops in Mexico The mango pulp is the only industrialized fraction discarding majorbyproducts of mango processing like peels and seeds which represent a serious disposalproblem and contributing to water pollution and plagues The aim of this study was theextraction and characterization of active biopolymers from seed and peel of mango TommyAtkins variety Samples were acquired during their commercial ripeness stage from a localmarket in Mexico City The biopolymers fractions from peel and seed kernel (germ) wereextracted and analyzed using Official Methods of AOAC and physicochemical methodsResults show that mango peel is an important source of raw fiber (19 ) and proteins (3 )also soluble carbohydrates (68 ) in which we can find pectin From seed kernels it is possibleto obtain starch (43 ) fat (12 ) and proteins (4 ) although this fraction did not have rawfiber nor pectin substances Results show that pectin from peel was of high methoxyl and hadlow acetylation It was not possible to determine the pectin fusion point due to its behavior ofamorphous polymer so a calcination point was greater than 220 degC From the seed kernel waspossible to isolate starch with high amylose and amylopectin The information obtained in thiswork could contribute to the use of the byproducts of mango Active biopolymers such as pectinand starch could give a value added to the crop and helping prevent waste production to theenvironment

Key words Biopolymers mango peel seed kernel starch pectin

INTRODUCTION

Mango is one the most harvested fruits in Mexico It has its origins in the Asian continentspecifically in the north area of India It was distributed all throughout Southeast Asia and lateron The Malay Archipelago The Portuguese took it to the African Continent and later on toBrazil and from there it disseminated to the whole American Continent [1] It belongs to theAnacardiaceae family and the Manguifera genus which includes 54 species most of themare small wild fruits found in general in India The specie Manguifera indica L is the mostcommercial harvested worldwide and exist different varieties [2]

According to NOM-129-SCFI-1998 [3] the Indostan group include several varieties which fruitshave a thick peel fibrous pulp and a big seed In Mexico already to half of production of (17million tons in 2015 according to SIAP [4]) belongs to Indostan group Currently it is consumedmainly as a fresh fruit leaving the peel and seed as waste [5] in this group we have varietiesas Haden Tommy Atkins Kent Irwin Keitt and Oro [6]

Vol 1 Pag55

The epicarp represents 10 to 20 of the fruit while the endocarp can make up to 30 [7]Process waste can result in 60 of the fruits total weight depending on the variety andripeness stage The most common use for the generated waste is cattle food However whendisposed on residual waters it affects its general quality and marine wildlife because of a risein eutrophication [8] There are some studies on the extraction of food additives using mangovarieties of Asian and Indian but there is no studies performed in Mexico With this the mainobjective of our study was the extraction and characterization of biopolymers from mangobyproducts because of the biopolymers extracted from the peel and seed could be importantin the food industry

Mango fruits Tommy Atkins variety were purchased from a local market in Mexico City Thefruits in a commercial maturity state were separated into fractions peel pulp and seed In theseed kernel and peel was performed the proximal chemical analysis [9] the results indicatedseveral components in greater proportion The pectin was extracted from peel while starchwas isolated from the seed kernel The characterization of the pectin included thedetermination of methoxylation [10] and acetylation [11] degree The germ was used for theextraction of starch using the method of Kaur [12] with some modifications In the starchisolated were analyzed total carbohydrates [13] and amyloseamylopectin relationship [14]

Having made the manual separation of fractions was obtained 115 plusmn 211 of peel pulp inthis variety was 7946 plusmn 312 while for the seed was determined a value of 902 plusmn 233In Tommy Atkins variety was possible to obtain about 20 of byproducts The fruits withcommercial maturity had a value of 1722 degBx plusmn 080 of total soluble solids with an acidity of003 plusmn 001 quantified as a percentage of citric acid After the characterization the peelswere separated into two groups The first group was used for the proximal chemical analysiswhile the second group was used for the pectin extraction In the case of the seed these wereseparated into his fractions in order to obtain the germ The Figure 1 shown the fractions afterthe extraction process of the cotyledons

Figure 1 Fractions of mango fruit after manual separationa) Peel (pericarp) b) Seed (endocarp) c) Seed kernel (germ)

The result of the chemical characterization of the fractions is shown in Table 1 As can beseen the peel of this fruit is rich in soluble carbohydrates the ash and raw fiber found to be

Vol 1 Pag56

significantly high in this fraction possibly due to pectin content From the cotyledons of thegerm was determined that it is rich in soluble carbohydrates The high content of solublecarbohydrates in all fractions indicate a high content of total sugars in the fruit

Table 1 Proximal chemical analysis of the fractions of mango Tommy Atkins

Ash Raw fiberSoluble

carbohydrate

Peel 462plusmn019 1975plusmn201 6843plusmn412Pulp 212plusmn002 470plusmn095 8906plusmn321Germ 253plusmn010 407plusmn008 7658plusmn486

Kratchanova [15] performed the quantifying of pectin in mango peel of Keitt variety On theother hand Kaur [12] report the presence of starch in the germ of mango Chausa TotapuriKuppi Langra and Dashehari According to these authors and the data shown in Table 1(related to the content of crude fiber and soluble carbohydrates) it can be assumed thepresence of pectin in peel and starch in cotyledons of Tommy Atkins variety

The peel pectin obtained was characterized as high methoxyl (9481 plusmn 09) and lowacetylation (0295 plusmn 003) degree It was not possible to determine the pectin fusion pointdue to its amorphous polymer behavior its dehydration temperature was 125 degC while thethermal calcination was detected at 245 degC Einhorn-Stoll [16] determined the calcinationtemperature near to 250 degC for citrus pectin with different treatments

Finally the starch yield from cotyledons of mango Tommy Atkins was quantitated 2674 plusmn128 Hassan [17] reported the presence of starch in four Nigerian varieties of mango in arange of 528 plusmn12 to 6537 plusmn111 depend on the variety For Tommy Atkins variety incommercial maturity the extracted starch represent an amount of amylose near to 2661 Kawaljit and Seung-Taik [18] reported 288 of amylose in starch of seeds of Chausa mangoas well as 336 in starch from Kuppi mango seeds cultivated in South Korea

CONCLUSIONS

The starch extracted from the Tommy Atkins seed kernel in commercial maturity present anamount of amylose near to 2661 similar to Asiatic varieties representing a new option fortheir extraction Pectin extracted from the peel was of high methoxylated and the calcinationpoint near of 245 degC represents a potential food additive useful at high temperature Theinformation obtained in this study could contribute to the use of the byproducts of mango (peeland seed kernel) since it was possible to extract and characterize pectin and starchbiopolymers which are of interest to the food industry

AKNOWLEDGEMENTS

The authors are grateful to CONACYT for the scholarship granted to JPR (219099) and for thetechnical support to Biol MP Meacutendez Castrejoacuten (chemical characterization) and to Ing M MaacuterquezRobles (thermal analysis)

Vol 1 Pag57

REFERENCES [1] Samson J A Fruticultura tropical Editorial Limusa Primera edicioacuten Meacutexico 1991 [2] Mora M J Gamboa P J y Elizondo M R Guiacutea para el cultivo del mango Ministerio de

agricultura y ganaderiacutea Costa Rica 2002 [3] NOM-129-SCFI-1998 Informacioacuten comercial ndash Etiquetado de productos agriacutecolas ndash Mango

Meacutexico Consultado en febrero de 2011 [4] SIAP Servicio de Informacioacuten Agroalimentaria y Pesquera Cierre de la produccion agriacutecola por

cultivo para 2015 en Meacutexico Disponible en httpwwwsiapgobmxcierre-de-la-produccion-agricola-por-cultivo Consultado en Julio de 2015

[5] SAGARPA Secretariacutea de Agricultura ganaderiacutea desarrollo rural pesca y alimentacioacutenPlan Rector Sistema Nacional Mango Comiteacute Sistema Producto Mango Meacutexico 2005

[6] Sergent E El cultivo del mango (Manguifera indica L) Botaacutenica manejo y comercializacioacuten Universidad Central de Venezuela Consejo de Desarrollo Cientiacutefico y Humaniacutestico 1999

[7] Ferreira S Peralta N A P Rodriacuteguez A G P Obtencioacuten y caracterizacioacuten de pectina a partir de desechos industriales del mango (caacutescara) Revisa colombiana de ciencias quiacutemico-farmaceacuteuticas 1995

[8] Assous M T M El-Wahab A E S and El-Waseif K H M Effect of microwave power on quality parameter of pectin extracted from mango peel Arab University Journal Agricultural Science 2007 15 395-403

[9] AOAC Official methods of analysis Association of Official Analytical Chemists Inc Washington E U 1995

[10] Schultz T H Determination of the degree of esterification of the ester methoxyl content of pectin by saponification and titration Methods Carbohydrate Chemistry 1965 5 189-194

[11] McComb E A and McCready M M Determination of acetyl in pectin and in acetylated carbohydrate polymers Anal Chem 1957 29(5)75-79

[12] Kaur M Singh N Sandhu K and Guraya H S Physicochemical morphological thermal and rheological properties of starches separated from kernels of some Indian mango cultivars (Manguifera indica L) Food Chemistry 2004 85 131-140

[13] Dubois M Gills K A Hamilton J K Rebers P A and Smith F Colorimetric method for determination of sugar and related substances Analytical chemistry 1956 28 (3) 350-356

[14] McGrance S J Cornell H J and Rix C J A simple and rapid colorimetric method for the determination of amylose in starch products Starch 1998 50 58-63

[15] Kratchanova M Benemou C Kratchanov C On the pectic substances of mango fruits Carbohydrate Polymers 1991 15 271-282

[16] Einhorn-Stoll U Hatakeyama H and Hatakeyama T Influence of pectin on water binding properties Food Hydrocolloids 2012 27 494-502

[17] Hassan L G Muhammad A B Aliyu R U Idris Z M Izuagie T Umar K J and Sani N A Extraction and characterization of starches from four varieties of Manguifera indica seeds Journal of Applied Chemistry 2013 3 16-23

[18] Kawaljit S S and Seungh-Taik L Structural characteristics and in vitro digestibility of mango kernel starches (Manguifera indica L) Food Chemistry 2008 107 92-97

Vol 1 Pag58

THE EFFECT OF ACCELERATED WEATHERING ON THE MECHANICAL BEHAVIOUR OF REINFORCED POLYPROPYLENE WITH COOPER NANOPARTICLES AND CARBON NANOTUBES

Janett Valdez-Garza1 Nuria Gonzalez-Angel1 Arturo Velazquez-de Jesuacutes1 Concepcion Gonzalez-Cantuacute1 Manuel Mata-Padilla1 Viacutector Cruz-Delgado1

Guillermo Martinez-Colunga1 Carlos Avila-Orta1 1Centro de Investigacioacuten en Quiacutemica Aplicada Blvd Enrique Reyna Hermosillo No 140 Col San

Joseacute de los Cerritos Saltillo Coahuila 25294 Meacutexico janettvaldezciqaedumx

Abstract The exposure of materials to the weather conditions like UV radiation heat and humidity is a problem for the plastics industry that requires extending the lifetime of these materials It is proposed to improve their properties by reinforcing them with nanoparticles [12] For this purpose polypropylene nanocomposites were prepared with copper nanoparticles and carbon nanotubes at different concentrations (0 1 25 and 5 wtwt) The materials were exposed to UV radiation humidity and heat The mechanical strength was evaluated for an exposure time of up to 1000 hours The tensile strength for nanocomposites is retained as the exposure time to ultraviolet radiation increases This effect is noticeable after 250 hours exposure and is more evident for nanocomposites with carbon nanotubes On the other hand the elongation behavior for nanocomposites with copper nanoparticles exhibits a reduction from 250 hours of exposure for the different contents of nanoparticles while nanocomposites with carbon nanotubes retain higher percentages of elongation greater than 100 even with exposure times of 1000 hours

Keywords Carbon nanoparticles accelerated weathering polymer nanocomposites

Experimental The extrusion process is most suitable and convenient method for homogeneous mixing of plastics with various additives Two masterbatch were prepared with 20 wtwt of copper nanoparticles and CNT Copper nanoparticles have an average size of 300 nm purity 995 and SSA 6 m2g they were supplied by SkySpring Nanomaterials Inc USA Industrial grade CNT (IGCNT) have an average diameter 20 nm length 20 ndash 40 micron SSA 220 m2g and were supplied by CheapTubes Inc USA Copper nanoparticles were coated with polyolefin wax to avoid oxidation and burning during handling prior to mix with polymer resin

Methodology A twin-screw extruder LD 401 Thermo Scientific 24-MC was employed to process all the samples with a plain temperature profile of 230 degC and 100 rpm Resin chips and powder were feed to the extruder with the assistance of gravimetric feeders for each one at a rate of 5 and 1 kgh respectively The samples were extruded with the assistance of ultrasound waves [3] provided by a home-made generator of variable amplitude and frequency in the range of 20 ndash 50 kHz and power of 500 W Both masterbatches were diluted to reach 0 1 25 and 5 of nanoparticle concentration in the same equipment without the use of ultrasound

Vol 1 Pag59

Characterization For the accelerated weathering exposure of the samples a QUV chamber was used with a long wave (UVA) at 340 nm a cyclic exposure consisting of 8 h of lightdarkness and temperature between 50 -70 ordmC in accordance with ASTM G154 standard method Time exposure was 0 250 500 750 and 1000 h 5 specimens were used for each exposure time Tensile testing was conducted using a Universal Testing Machine INSTRON model 4301 at 5 mmmin using type V specimens in accordance with ASTM D638 standard method

Figure 1 Experimental route for the preparation of nanocomposites and exposure conditions for accelerated weathering Results The tensile stress versus exposure time for nanocomposites at different concentrations of nanoparticles is shown in Figure 2 Polypropylene resin exhibit a noticeable reduction in mechanical properties after 250 hours of exposure and this effect is more evident as the time increases reached a value of 5 MPa after 1000 h For nanocomposites with CNT it is possible to observe that mechanical properties are retained almost without change during the entire exposure time and this effect are homogeneous for all CNT concentrations showing that the 1 is sufficient to protect the polymer against the UV light degradation

Figure 2 Tensile stress versus exposure time for nanocomposites at different concentrations of nanoparticles

Vol 1 Pag60

For copper nanoparticles it is possible to observe a reduction in mechanical properties as the time exposure to UV light increase and this is independent of the concentration of nanoparticles This behavior suggests that copper nanoparticles are not suitable for the protection of polymers against UV radiation Elongation at break is another important property in polymers and it is affected by the UV light in outdoor conditions due that is highly necessary to find alternative additives to protect plastics In Figure 3 the elongation at break versus exposure time for nanocomposites at different concentrations of nanoparticles is shown In accordance with the tensile stress behavior shown by the polypropylene resin the elongation at break decreases after 250 hours of exposure time this means that material becomes fragile and brittle Nanocomposites with 1 and 2 wtwt of CNT present a monotonically reduction of elongation as the exposure time increases and retain around 100 of elongation after 1000 hours of exposure to the UV light The sample with 5 wtwt of CNT shown lower elongation at begins of the test and this property remains without change over the entire exposure time On the other hand nanocomposites with copper nanoparticles exhibit a noticeable reduction of elongation at break after than only 250 hours which correspond with the tensile stress behavior shown above therefore copper nanoparticles are inappropriate for the weathering protection of plastics These results show clearly that CNT are an effective additive to prevent the degradation of polypropylene by UV light probably by the absorption of high-energy radicals involved in the photodegradation process

Figure 3 Elongation at break versus exposure time for nanocomposites at different concentrations of nanoparticles Different reports in literature suggest that concentrations of CNT lower than 1 wtwt promotes the photo-oxidation mechanisms in polyolefins by the increase of carbonyl index and suggest a pro-degrading effect associated with a more homogenously dispersed carbon nanoparticles [4] As the content of nanoparticles increases CNT act as an effective and alternative UV stabilizer for polypropylene and polyethylene resins In another study [5] the effectiveness of nanoparticles different to CNT was studied and concluded that silicon oxide (SiO2) nanoclays like montmorillonite (MMT) or organic modified montmorillonite (oMMT) are less effective to protect polymers against photo-induced degradation as we can observe in the case of copper nanoparticles

Vol 1 Pag61

Conclusions The exposure to UV radiation affect the mechanical properties of polypropylene after only 250 hours and this tendency increases as the exposure time increases too The addition of CNT in contents of 1 25 or 5 wtwt provides UV stabilization to polypropylene resin as observed by the retention of tensile strength and elongation at break in nanocomposites Nevertheless for nanocomposites with copper nanoparticles the photo-degradation phenomenon was observed after only 250 h in similar manner to the neat polypropylene From the above results it is possible to conclude that CNT act as an effective and alternative UV stabilizer for polypropylene resins and to extend the shelf life of the polymer besides to bring mechanical reinforcement and the ability to conduct heat and electricity (unpublished results)

References

[2] Polym Degrad Stabil 2010 95 1614

Acknowledgements We acknowledge the financial support from Fondo SENERCONACYT under CeMIE-Sol program Project 20745012 Authors thank Rodrigo Cedillo and Fabian Chavez by their assistance with processing of polymer nanocomposites

Vol 1 Pag62

ATRAZINE REMOTION FROM AQUEOUS SOLUTIONS WITH A POLYMERCLAY COMPOSITE

Alejandra Abigail Zuacutentildeiga-Peacuterez12 Mariacutea del Carmen Diacuteaz-Nava 1 Javier Illescas1

1 Instituto Tecnoloacutegico de Toluca Av Tecnoloacutegico SN Col Agriacutecola Bellavista CP 52169 Metepec Estado de Meacutexico Meacutexico

2 Universidad Tecnoloacutegica del Valle de Toluca Carretera del Departamento del DF km 75 Santa Mariacutea Atarasquillo Lerma Estado de Meacutexico Meacutexico

cardinavaposgradogmailcom

Introduction The use of atrazine in agriculture has led to high levels of contamination in water systems and has been the subject of various investigations such as adsorption and degradation These are the main natural attenuation mechanisms that control the migration of this herbicide in water and soil Adsorption of atrazine depends on the texture and composition of soil pH and principally the applied amount of herbicide The adsorbent materials such as clays are of interest for their possible regeneration They can withstand higher temperatures than activated carbon and can even regenerate in the absence of heat without reducing its lifetime Another important feature is their mechanical strength which is higher than the activated carbon

In this work atrazine has been removed from aqueous solutions by using natural clay which has been modified with HDTMA-Br by two different methods (A and B) incorporated into alginate beads with different clay contents

Experimental Composites were prepared by two methods A) 97 mL of hot deionized water were put into a beaker on a magnetic stirrer until it reaches 343 K Then 03 g of sodium alginate were added and stirred with a magnetic bar until dispersed At that point 01 g of modified or natural clay were placed and stirred until clay and alginate were totally mixed After that the mixture is placed in a syringe and added dropwise into a CaCl2 under stirring at constant temperature Once the beads were synthesized they were left in the same solution for 24 h In method B) a certain amount of clay according to the desired load weight was dispersed in 50 mL of deionized water The mixture was kept under constant stirring for 2 h On the other side1 g of sodium alginate was dissolved in deionized water at 333 K under constant stirring for 2 h Then alginate was added to the modified clay suspension keeping constant stirring at 333 K for 2 h The synthesized alginatemodified clay beads were collected dropwise with a syringe into a 001 M solution of CaCl2 where they were maintained under constant stirring until they were placed in the refrigerator for 24 h

Vol 1 Pag63

Adsorption of atrazine onto the clay-composites was performed in batch experiments as follows 10 mL of atrazine solution was placed in contact with 500 mg of composite During adsorption experiments a vial containing an atrazine solution was stirred at 298 K and 100 rpm on a thermobath for 6 h

Results and discussion The atrazine concentration present in aqueous solution was measured between 190-300 nm It was observed that the maximum wavelength absorption for this herbicide in different aqueous solutions prepared with different concentrations was 222 nm as shown in Figure 1 Furthermore this wavelength value was selected for measurement of atrazine in aqueous solutions with different concentrations and the calibration curve was constructed Figure 2 shows the obtained graph

Figure 1 Absorption spectra of Atrazine

Figure 2 Calibration curve of Atrazine in aqueous solution

Tables 1 and 2 summarize the obtained results for the removal of atrazine with two different clay-composites synthesized from methods A and B As it can be seen this percentage is similar for both composites synthesized by means of method A or B

Vol 1 Pag64

Table 1 Removal of atrazine (A) for 24 h with a natural clay-composite (NCC) or modified clay-composite (MCC) obtained from method A

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

Prom mg Atrazine g composite (mgAgP) DS

24 h NCC 1wt

01 52 00 220 012 0001

MCC 2wt

01 51 01 255 013 0015

MCC 5wt

01 51 01 360 023 0010

Table 2 Removal of atrazine (A) for 24 h with a natural clay-composite (NCC) or modified clay-composite (MCC) obtained from method B

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

Prom mg Atrazine g composite

(mgAgP) DS

NCC 2wt

0217 39 09 0 005 0021

MCC 2wt

0213 23 01 5 013 0014

24 h MCC 4wt

0208 19 01 22 015 0005

MCC 6wt

0220 19 01 23 014 0010

MCC 8wt

0210 20 04 22 015 0004

Finally Figure 3 shows the zero load point which is the pH where the total charge of the particles from the surface of an adsorbent is zero It is important to determine it since this is a parameter that indicates the load of the material at different pH values In our particular case it shows that the zero load point of the alginate beads is approximately equal to 68

Vol 1 Pag65

Figure 3 p H v s pHo of modified beads with 2 wt- clay content Conclusions From these set of results it has been concluded that the efficiency for both polymerclay composites (A or B) is similar for the atrazine removal It has been observed that in synthesized beads with concentrations of 5 wt- of modified clay greater absorption values of the contaminant have been obtained Finally the adsorption capacity of atrazine in aqueous solutions for the synthesized polymerclay composites was found between 012 and 023 mg atrazineg material depending on the clay content

AcknowledgmentS We are thankful to CONACyT for the project 3056 ldquoCaacutetedras-CONACyTrdquo and to Tecnoloacutegico Nacional de Meacutexico (TecNM) for the project 564615-P for their financial support

References

[1] E I Unuabonah E I et al Appl Clay Sci 2014 99 83-92[2] M C Diacuteaz Nava et al J Incl Phenom Macrocyc Chem 2012 74 67-75[3] V Golla et al J Environm Sci Eng 2012 5 955ndash961[4] C Salinas-Hernaacutendez et al Water Air Pollut 2012 223 4959-4968[5] M C Diacuteaz-Nava et al J Incl Phenom Macrocyc Chem 2005 51 231-240

Vol 1 Pag66

PLASMON-PHONON COUPLING IN MULTILAYER GRAPHENE ON POLAR SUBSTRATES

G Gonzalez de la Cruz

Departamento de Fisica CINVESTAV-IPN apartado postal 14-740 07000 CDMX Mexico batofiscinvestavmx

ABSTRACT

We investigated the effect of polar substrates on the collective excitations of a semi-infinite layered graphene structures within the self-consistent field approximation The surface plasmon dispersion in semi-infinite stack of graphene layers is indeed modified via Coulomb interaction with polar substrate At long wavelengths (qrarr0) these new surface-polaritons are situated above bulk plasmon band of the stack with an infinite number of layers and they have a very long lifetime However at large momentum transfer the collective surface modes being sensitive to decay into a continuum plasmon band or by emitting an electron-hole pair excitation (Landau damping) due of the relativistic Dirac nature of charge carriers in graphene

INTRODUCTION

Graphene a two-dimensional (2D) crystal of carbon atoms arranged in a honeycomb lattice owes its extraordinary optical and electronic properties to the presence of Dirac points in its band structure [1] Graphene two-dimensional plasmons exhibit unique optoelectronic properties and enable extraordinary light-matter interactions Many of the peculiarities of massless Dirac fermions in graphene are related to their collective excitations [2] A plasmon is a collective mode of a charge-density oscillation in a free-carrier density which is present in both classical and quantum plasmas Studying the collective excitation in the electron gas has been among the very first theoretical quantum mechanically many-body problems studied in solid-state physics Owing to the two-dimensional nature of the collective excitations plasmons excited in graphene are confined much more strongly than those in conventionally noble metals The strong linear and nonlinear interactions of massless Dirac fermions with light together with the tunable conductivity and broadband response make graphene an attractive material for atomically thin active devices operating at optically and therahertz frequencies with extremely high velocity Graphene is an ideal material for the emerging field of plasmonics References [3-8] focus on the recent progress of graphene plasmonics and its technological applications in different optoelectronic areas Plasmon-phonon coupling has been observed experimentally for graphene on SiC (0001) [9] and theoretically investigated [10] solving Maxwell equations with appropriate boundary conditions at the interfaces between graphene-substrate system and more recently the semiclassical Monte Carlo method was used to calculate the electron mobility in graphene on different substrates [11] Recently experiments have been performed to investigate the strong coupling between graphene plasmons and a

Vol 1 Pag67

monolayer hexagonal boron nitride phonons showing two clearly separated hybridized surface-plasmon-phonon-polariton modes that display an anticrossing behavior [12] So far the study on graphene collective modes has been mostly focused on plasmons in monolayer graphene double layer sheets [13-14] and recently in hybrid relativisticnon-relativistic coupled two-dimensional electron layers [15-16] The coupling of plasmons in a periodic multilayer graphene system which is physically different from that in double-layer system is also and important topic and it has been explored in several scientific papers [17-20] In this paper we investigate the role of oxide (semiconductor) substrates on the collective excitations (plasmons) in multilayer graphene Our model provides a systematic description of an array composed of periodically stacked graphene layers with identical interlayer spacing coupling via surface charge density oscillations with the substrate optical surface phonons The mode follows the graphene semi-infinite superlattice immersed in a material of background dielectric constant εs growth on a substrate with a dielectric constant ε0 We use such configuration to study the strong plasmon-phonon hybridization and explore new different spectral modes II Theoretical model Here we study the coupling between the two-dimensional semi-infinite superlattice graphene system and the substrate The model system under consideration corresponding semi-infinite graphene electron layers separated a distance d is shown in Fig1 The graphene electron layers system occupy a half-space zgt∆+nd (n=0123hellip) of background dielectric constant εs The substrate with dielectric constant ε0 occupies the space zlt0

Fig 1 Within the self-consistent-field linear approximation theory (SCF) and assuming the relaxation time be infinite each electron is assumed to move in the self-consistent field arising from the external field plus the induced field of all the electrons then the electron density in the nth (n=01) graphene electron layer ρn(qω) in zero external field is given by

ρn (qω) = Vnm (q)Πm (qω )ρm (qω )msum (1)

Vol 1 Pag68

Vnm (q) = vq eminusq n minusm d + αeminus(n +m )d[ ] (2) is the interlayer Coulomb interaction and the second term proportional to

α = (ε s minusε 0) (ε s +ε 0)eminus2∆q gives the modified Coulomb interaction between the two Dirac electron layers due to the image charge and Πn(qω) is the two-dimensional polarizability for layer n calculated in Refs [8] [9] and vq=2πe2εsq represents the two-dimensional Coulomb electron interaction On the other hand to describe surface modes we make the assumption that

ρm (qω ) = exp(minusmβq)ρ0(qω ) for mgt0 where β-1 is a decay length of the excitation away from the interface and we require that Reβgt0 Using the relation of ρm(qω) in Eq(15) one finds

vqΠ(qω ) eminusβ (m minusn )dVnm (q) =1msum vq = 2πe2 ε sq (3)

The latter equation determines the value of the decay parameter β-1 It turns out to be an analytical result given as

exp(minusβd) =cosh(∆q) +ε r sinh(∆q)

cosh(d minus ∆)d minusε r sinh(d minus ∆)d(4)

For a semi-infinite carrier layers the zeros of the dielectric function give the dispersion relation for the surface plasmon (SP) modes

Ds(qω ) = 2vqΠ(qω) minus(1minusε r

2)sinh(qd)[cosh ∆q +ε r sinh ∆q][cosh(d minus ∆)d minusε r sinh(d minus ∆)d]

In graphene semi-infinite superlattice on semiconducting substrates (Fig1) it is easy to incorporate the coupling to optical phonons One only has to replace the frequency-independent background dielectric constant ε0 by a frequency dependent

where ωl and ωt are the longitudinal and transverse optical-phonon frequencies which are related with the dielectric constants by the

Lyddane-Sachs-Teller relation and is the static (high frequency) dielectric function By taking into account the frequency dependence of the dielectric function we find the coupled bulk and surface plasmon spectrum for a graphene semi-infinite superlattice on polar substrate In Fig 2 we show the calculated coupled plasmon-phonon modes collective modes in graphene semi-infinite superlattice on polar substrate for two different distance from the first graphene layer to the substrate In ordinary semiconductor superlattice the plasmon-phonon mode coupling emerges above the continuum plasmon band and is unable to decay in plasmon band and a single electron-hole pair However in multilayer graphene structures the hibridization of collective electron excitations with surface phonons in the substrate the coupled modes can decay into plasmons Fig 2a or they are Landau damping Fig 2b this latter phenomenon is direct consequence of

Vol 1 Pag69

the singular behavior in the graphene electron polarizability Notice the plasmon like mode cannot exist due to the restriction on the decay of the evanescent electromagnetic field associated with the surface collective excitation Eq(4)

CONCLUSIONS In conclusion we have analyzed the screening of plasmons in semi-infinite superlattice graphene on semiconducting and metallic substrates within the self-consistent field approximation The hybridization between charge density collective excitations in multilayer grapheme structure and phonons on polar substrates the energies of the collective modes can be significantly shifted and the resulted surface plasmon polaritons modes are long-lived collective excitations in the long wavelength limit However these hybrid modes can decay into plasmon band or are Landau damping in the SPE continuum This latter singular feature is a direct consequence of the electronic properties of graphene in contrast with surface plasma excitations in conventional layered two-dimensional -electron gas which are not subject to Landau damping REFERENCES

[1] AHF Castro F Guinea NMR Peres KS Novoselov K and AK Geim Rev Mod Phys 81 109 (2009) [2] AN Grigorenko M Polini and KS Novoselov Nature Photonics 6 749 (2012) [3]S DasSarma S Adam EW Wang and E Rossi Rev Mod Phys 83 408 (2011) [4] L Ju B Jeng J Horng C Girit M Martin Z Hao HA Bechtel X Liang A Zettl YR Shen and F Wang Nature Nanotech 6 630 (2011) [5] W Zhu ID Rukhlenko LM Si and M Premaratne Appl Phy Lett 102 121911 (2013) [6] YV Bludov A Ferreira NMR Peres and MI Vaselevskiy Int J Mod Phys B 27 1341001 (2013) [7] T Otsuji V Popov and V Ryzhii J Phys D Appl Phys 47 094006 (2014) [8] Y Cai J Zhu and QH Liu Appl Phys Lett 106 043105 (2015) [11]RJ Koch T Seyller and JA Schaefer Phys Rev B 82 201413 (2010)

Vol 1 Pag70

[12] ZY Ong andM Fischetti Phys Rev B 86 165422 (2012) [13] VW Brar M Jang M Sherrot S Kim J Lopez LB Kim M Choi and H Atwater Nano Lett 14 3876 (2014) [14] B Bunch T Stauber F Sols and F Guinea New J Phys 8 318 (2006) [15] EH Hwang and S Das Sarma Phys RevB 80 205405 (2009) [16] SM Badalyan and FM Peeters Phys RevB 85 195444 (2012) [17] RE Profumo R Asgari M Polini and AH MacDonaldPhys Rev B 85 085443 (2012) [18] AC Balaram JA Huatasoit and JK Jain arXiv1405-4014v2 (2014) [19] A Gamucci D Spirito M Carrega B Karmakar A Lombardo M Bruna AC Ferrari LN Pfeiffer KW West M Polini and V Pellegrini arXiv14010902v1 (2014) [20] W Norimatsu and M Kusonoki Semic Sci Technol 29 064009 (2014) [21] J Kim and G Lee Appl Phys Lett 107 033104 (2015) [22] KWK Shung Phys RevB 34 979 (1986) Acknowledgments This work was financially partially supported by Conacyt

Vol 1 Pag71

Design and synthesis of new small molecules for electronicorganics via direct hetero-arylation using ligand-less palladium

catalyst

K I Moineau-Chane Ching1 C Chen1 D Le Borgne1 D HernandezMaldonado1

1CNRS LCC (Laboratoire de Chimie de Coordination) 205 route de Narbonne Universiteacute de

Toulouse UPS INP LCC 31077 Toulouse France kathleenchanelcc-toulousefr

INTRODUCTION

Organic photovoltaics have been intensively investigated for their advantages as low cost lowweight and their easy process on large flexible substrates Much of the attention have beenfocused on the development of electron donor (D) polymer associated with electron acceptor(A) phenyl-C61-butryric acid methyl ester (PC61BM) or PC71BM Recently small molecules haveconfirmed to be as efficient as polymers with record power conversion efficiencies (PCEs) upto 1008 [1] when used as D-materials and paired with PC71BM [12] or as A-materials toreplace PCBM [3-4] reaching PCE near 8 with PTB7-Th [5] Moreover they offer a betterreproducibly simpler synthesis and purification than polymers The development of A-smallmolecules is a challenge because fullerene derivatives are expensive difficult to purify havea poor absorbance in UV-visible spectrum and their optoelectronic properties are hard toengineerTherefore we design and synthesize small molecules based on benzothiadiazole andthiophene moieties owing to their potential capabilities in withdrawing and donating electronrespectively Particularly we focused on developing a green coupling method namely directheteroarylation[6] that requires neither toxic nor complicated to generate interestingintermediates with low loading of ligand-less palladium-catalyst

The basic idea of this study is to provide small as simple as possible molecules obtained afteras few synthetic steps as possible from commercially available raw materials The need oftwo steps is believed to be the minimum reachable path leading to the fewest waste productionand lowest cost 47-dibromobenzo-213-thiadiazole (diBrBz molecule 1) acts here as theelectrophile on both sides in reaction with 2-thiophene carboxaldehyde (TCHO molecule 2)which is found here to be exclusively 5-arylated thus providing either D-A-D or A-Dintermediates for building semi-conducting small molecules For symmetrical D-A-Dintermediate the presence of two aldehyde functions at both extremities renders possible toelongate the molecule by a double Knoevenagel condensation leading to an A-D-A-D-Amolecule which is suitable for presenting semiconducting character associated with low bandgap properties For non-symmetrical A-D intermediate the remaining bromine atom on

Vol 1 Pag72

benzothiadiazole on one side allows to elongate the molecular structure by reaction with another D moiety that will constitute de core of the new D-A-D-A-D generated aldehyde flanked molecule In the same manner as previously described the presence of two aldehyde functions at both extremities of the D-A-D-A-D core renders possible to elongate the molecule by a double Knoevenagel condensation leading to an A-D-A-D-A-D-A molecule Among the available terminal electron-withdrawing groups alkyl (R) cyanoacetate are often chosen[7-9] Both octyl cyanoacetate (O) and 2-ethylhexyl (EH) cyanoacetate are very often chosen as the terminal groups because they confer a good solubility of the final molecule promote self-organization in nanoaggregate structures and contribute to enhanced photovoltaic performances[10] Among the target molecules we aim to synthesize symmetrical molecules such as Bz(T1CAR)2 or DTS[Bz(T1CAR)]2 in which ldquoDTSrdquo stands for dithienosilole central core and ldquoCARrdquo for alkyl cyanoacetate end group These target molecules are achievable in two to three steps only Their benzothiadiazole precursors either symmetrical Bz(T1CHO)2 or non-symmetrical Bz(T1CHO) are obtained from commercially available reagents such as diBrBz and TCHO via direct heteroarylation[6] as demonstrated here Symmetrical benzothiadiazole D-A-D intermediate This symmetrical molecule is designed around a central acceptor fragment the benzothiadiazole and its synthesis has been developed using a green coupling method the direct heteroarylation that requires neither toxic nor complicated intermediates such as stanyl or boronyl derivatives[6] Herein the preparation of intermediate 3 has be achieved at low palladium-catalyst loading without ligands producing very few remaining toxic wastes (see Scheme 1)

Scheme 1 reaction scheme for synthesis of intermediate 3

This route proved to be reasonably efficient with a reaction yield of 71 in isolated molecule when 22 equivalent of 2 are engaged for one equivalent of 1 Moreover this reaction exhibits good green metrics (E-Factor = 143) and proceeds at low cost (evaluated cost of synthesized intermediate 14 eurog)[11] It was possible to improve the reaction yield and to decrease the amount of degradation products associated with side reactions experienced by 2 Indeed the analysis and workup of the by-products revealed that non-reacted molecule 1 is totally recovered whereas the molecule 2 undergoes degradation products besides the desired one For avoiding as much as possible the formation of wastes the molecular ratio between 2 and 1 was lowered to 09 then 05 (instead of 22) The obtained values are gathered in Table 1 The reaction yield is improved but with much worse green metrics This is due to the fact that the non-reacted molecule 1 (when used in excess) is accounted in our calculations as a waste thus this substantially contributes to the increase of the calculated value of the E-factor Due to the fact that molecule 1 does not react by homocoupling reaction nor decomposes through any other degradation processes under these reaction conditions it may possible to recycle it

Vol 1 Pag73

Thus with optimized synthesis conditions including the recycling of 1 it is feasible to synthesize 3 in quantitative yield with an E-factor approaching 143 gg and a cost of around 14 eurog as reported for reaction conditions indicated in the first column of Table 1 Table 1 Reaction yields E-factors and costs calculated for the synthesis of 3 obtained via in decreasing the 21 ratios (r)

r = 22 r = 09 r = 05

Yield () 71 100 100

E-factor (gg) 143 226 408

Cost (eurog) 14 22 39

Non-symmetrical benzothiadiazole A-D intermediates As for the symmetrical molecule intermediate 4 (see structure below) was obtained via the same reaction path In that case and for avoiding the diarylation we tested different reaction conditions such as playing with the 21 ratio the amount of catalyst and base and various temperatures and time of reaction It is worth to note that once again the non-reacted dibromobenzothiadiazole can be recovered thus easily reused in the successive attempts The best obtained result was a 35 yield in isolated product which was obtained under the following condition molar ratio 21 is 05 15 equivalent of potassium acetate (KOAc) and 1 mol catalyst palladium acetate (Pd(OAc)2 relative to compound 1 6 mL of NN-dimethylacetamide (DMA) and stirring at 105 degC for 21 h under argon atmosphere Compared to the 30 yield of isolated product obtained via Suzuki coupling direct C-H arylation appears to be slightly more efficient than traditional methods and much greener CONCLUSION In summary direct heteroarylation arylation procedures with many different operating conditions were developed to obtain the di-arylated compound 3 and the mono-arylated compound 4 Whereas the yield in di-arylated compound 3 was reached up to 100 the best yield in isolated mono-arylated compound 4 is 35 Therefore the direct arylation without ligand nor additive proved to be a nice efficient coupling protocol for the formation of new C-C bond These intermediates can now be used in further reactions such as directly Knoevenagel

Vol 1 Pag74

condensation for compound 3 whereas the mono-arylated compound 4 will be coupled with stannyl-containing dithienosilole (DTS) derivatives to yield conjugated DTS-based small molecules for organic electronics applications Works in this aim are in progress

References [1] B Kan M Li Q Zhang F Liu X Wan Y Wang W Ni G Long X Yang H Feng Yi M Zhang F Huang Y Cao T P Russel and Y Chen J Am Chem Soc 2015137 3886-3893 [2] DH Wang AKK Kyaw V Gupta GC Bazan and AJ Heeger Adv Energy Mater 2013 3 1161-1165 [3] JD Douglas MS Chan JR Niskala OP Lee AT Yiu EP Young and J-M Freacutechet Adv Mater 2014 26 4313-4319 [4] L Chen L Huang D Yang S Ma X Zhou J Zhang G Tu and C Li J Mater Chem A 2014 2 2657-2662 [5] M Li Y Liu W Ni F Liu H Feng Y Zhang T Liu H Zhang X Wan B Kan Q Zhang T P Russell and Y Chen J Mater Chem A 2016 4 10409-10413 [6] J Roger F Požgan and H Doucet Green Chem 2009 11 425-432 [7] Y Kim C E Song S-J Moon and E Lim Chem Commun 2014 50 8235-8238 [8] J Zhou X Wan Y Liu G Long F Wang Z Li Y Zuo C Li and Y ChenChem Mat 2011 23 4666-4668 [9] Y Liu X Wan F Wang J Zhou G Long J Tian J You Y Yang and Y Chen Adv En Mat 2011 1 771-775 [10] K-H Kim H Yu H Kang DJ Kang C-H Cho H-H Cho JH Oh and BJ Kim J Mater Chem A 2013 1 14538-14547 [11]C Chen D Hernaacutendez Maldonado D Le Borgne F Alary B Lonetti B Heinrich B Donnio and KI Moineau-Chane Ching New J Chem 2016 DOI 101039C6NJ00847J

Acknowledgements The authors gratefully acknowledge financial support from French Region Midi-Pyreacuteneacutees and IDEX Transversaliteacute laquo dessine moi OPV raquo Consejo Nacional de Ciencia y Technologia (CONACyT Mexico) and China Scholarship Council (China) This work has been also performed within the Framework of the French-Mexican International Laboratory (LIA-LCMMC) supported by CNRS and CONACyT

Vol 1 Pag75

Microwave synthesis and characterization of a supramolecular

βCD-based crosslinked network

Yareli Rojas-Aguirre1 Geovanni Sangabriel-Gordillo1 Israel Gonzaacutelez-Meacutendez1

1Departamento de Farmacia Facultad de Quiacutemica Universidad Nacional Autoacutenoma de MeacutexicoCiudad Universitaria CP 04510 Meacutexico DF Meacutexico

yarelirojasgmailcom

Abstract

The synthesis of supramolecular networks using cyclodextrins as the crosslinking points isgaining attention because of their potential applications in a number of fields In this work wepresent the synthesis of a β-cyclodextrin (βCD) network with carbonyldiimidazole (CDI) as thecrosslinking agent using microwave irradiation This approach allowed obtaining the productin 45 minutes instead of the 8 h that takes the conventional synthesis The physicochemicalcharacterization confirmed the identity of the material which showed in addition an improvedhost-guest complexation efficiency

Introduction

Cyclodextrins (CDs) are cone shaped cyclic oligosaccharides formed by glucopyranose unitsin which the outer surface is hydrophilic while the cavity holds a hydrophobicmicroenvironment Hence CDs can host molecules of different nature resulting in theformation of inclusion complexes [1] The synthesis of CD-based crosslinked networks isbecoming popular in current research In these systems the CDs can act as the crosslinkingpoints and interact with guest molecules simultaneously The crosslinker the reactionconditions and the stoichiometry will determine the degree of crosslinking the characteristicsof the mesh the size and the shape of the system and therefore gels polymer particles orcontinuous porous structures can be obtained [2]Trotta and co-wokers have been pioneers in the synthesis of hypercrosslinked CD systemsAmong them is the one called carbonate nanosponge a crystalline nanometric structureobtained from the reaction of βCD and CDI as the crosslinking agent [3] Inspired by the workof Trotta and taking into account the potential applications of the βCD-based crosslinkednetworks we consider that the generation of these materials rapidly with the possibilities toscale up their production is of great importance In this sense we herein present the synthesisand characterization of a βCD network with CDI as the crosslinking agent using microwaveirradiation (βCD-CL-MW) In parallel the crosslinked system using the conventional heatingmethod was also synthesized (βCD-CL-H)

Materials and methods

CDI βCD dimethylformamide (DMF) and ethanol were purchased from Sigma-Aldrich andused without further purification Milli Q water was used for all the experiments

Vol 1 Pag76

βCD-CL-H was synthesized following the reported methods [4] βCD-CL-MW was performedin an Anton-Parr Monowave 450 at 120degC and stirring rate of 500 rpm the reaction wasmonitored through the integrated camera Both βCD-CL-H and βCD-CL-MW were preparedwith a stoichiometric ratio βCD-CDI 14 The FTIR reflectance spectra were acquired in aPerkin Elmer Spectrum 400 The powder x-ray diffraction was carried out in a Bruker D8Advance diffractometer using Cu ƙα (λ=15406 Aring) radiation with 30 mA current and voltage of35 kV The SEM micrographs of the gold sputtered samples were taken in a Jeol JSM 5900LVin SEI mode voltage of 20 kV work distance of 11 mm and spot size of 22 To determine thecomplexation efficiency an amount of phenolphthalein (Phen) was added to a suspension ofthe crosslinked systems the samples were centrifuged and the free Phen was quantified in aUV-Vis spectrophotometer at 553 nm (Genesys 10UV Thermo)

Results

Two βCD-based crosslinked structures were prepared βCD-CL-H was obtained after 8 hwhile βCD-CL-MW was produced in only 45 min The systems were obtained as poroussurface micrometric aggregates (Figure 1) The particle size was confirmed through theiranalysis in a zetasizer instrument (Malvern) and was found to be in the range of 4-5 microm

Figure 1 SEM micrographs of A) βCD B) βCD-CL-H and C) βCD-CL-MW

Both βCD-CL-MW and βCD-CL-H were characterized in order to confirm their identity TheIR spectra showed the characteristic band of carbonate group at 1750 cm-1 indicating thecrosslinking between CDs through carbonate moieties in both cases (Figure 2B and 2C)whereas the IR spectrum of native βCD did not display this peak (Figure 2A) The diffractionpattern of βCD revealed the crystallinity of the native macrocyle which is lost in some extentwhen is crosslinked Interestingly the degree of crystallinity in βCD-CL-MW seems to be higherthan βCD-CL-H (Figure 3)

Vol 1 Pag77

Figure 2 FTIR spectra of A) βCD B) βCD-CL-H and C) βCD-CL-MW

Figure 3 X-ray diffractograms of A) βCD and B) crosslinked systems

Both βCD-CL-MW and βCD-CL-H were incubated in the presence of Phen a well known guestfor the macrocyle The crosslinked systems were more efficient forming complexes than βCDThis can be due to a cooperative effect that βCD rings have when they are close together [1]and because the guest molecules could also be trapped in the interstitial spaces in thecrosslinked structure It was found that the complexation ability and the impregnation volumeof βCD-CL-MW material was higher than βCD-CL-H (Table 1) The latter was performed inorder to indirectly know the porosity and the amount of water that can be taken by the materialThese results show that besides the reduction of the reaction time the microwave irradiationinfluences the crosslinking ratio and the order in which the macrocycles are packed to form theporous structure This in turn will determine the entrapment capacity of the supramolecularmaterials and the further applications they could have

Vol 1 Pag78

Table 1 Specific features of the BCD crosslinked systems

System Reactiontime

Yield()

Impregnationvolume (mlg)

Complexationefficiency ()

Native βCD --- --- 053 684βCD-CL-H 8 h 49 161 792

βCD-CL-MW 45 min 57 316 873

Conclusions

Two βCD-based crosslinked systems were synthesized As expected the reduction in thereaction time when working in a microwave reactor decreased dramatically from 8 h to only 45minutes The microwave irradiation produced structures with an enhanced capacity to forminclusion complexes and to entrap water molecules than the same materials obtained by theconventional synthetic methods These outcomes open the door to a fast production ofmaterials with improved properties and to the possibilities for expanding their applicationswhich will be part of our future work

References

[1] Loftsson T Duchecircne D Int J Pharm 2007 329 (1-2) 1ndash11[2] Concheiro A Alvarez-Lorenzo C Adv Drug Deliv Rev 2013 65 (9) 1188ndash1203[3] Cavalli R Trotta F Tumiatti W J Incl Phenom Macrocycl Chem 2006 56 (1-2) 209ndash213[4] Lembo D Swaminathan S Donalisio M Civra A Pastero L Aquilano D Vavia P Trotta FCavalli R Int J Pharm 2013 443 (1-2) 262ndash272

Acknowledgment

The authors thank Prof Francisco Hernaacutendez-Luis for the technical assistance and facility of the Anton-Parr Microwave Reactor and Facultad de Quiacutemica UNAM for the financial support (PAIP 5000-9157)

Vol 1 Pag79

SYNTHESIS AND CHARACTERIZATION OF MESO-SUBSTITUTED BORON DIPYRROMETHENES (BODIPY)

Gerardo Zaragoza-Galan1 EA Garciacutea Mackintosh D Chaacutevez-Flores A Camacho-Daacutevila L Manjarrez-Nevaacuterez

1Universidad Autoacutenoma de Chihuahua Facultad de Ciencias Quiacutemicas gzaragozauachmx

Abstract The synthesis of four meso-substituted Boron-Dipyrromethene derivatives (BODIPY labelled 1 2 3 4 respectively) using lsquorsquoconventionalrsquorsquo chemical methodologies (in presence of solvents) and mechanochemical methodologies (solvent-free) is reported

N NBF2

(Not isolated)

NH H O

R1234+

1) 3)CH2Cl2 Ar1) TFA 1-2 drops 2-12h2) DDQ 1 eq 30min3) Et3N 5eq BF3OEt2 5eq 0C 3h

Conventional Method

R1= 4-Hydroxy-3-methoxybenzaldehydeR2= 4-Hydroxybenzaldehyde R3= 4-MethoxybenzaldehydeR4= 1-Pyrenecarboxaldehyde

2 eq 1 eq

1) TFA 5 drops 1min2) 2ml CH2Cl2 DDQ 1 eq 1 min3) Et3N 3 mlBF3OEt2 3ml1 min

Mechanochemical

1 Introduction44-difluoro-4-bora-3a4a-diaza-s-indacene dyes (abbreviated as BODIPY) are composed oftwo units of pyrrole which are connected by a methene in the 2-position and a boron atomcoordinated by the N-heteroatom BODIPY dyes are highly absorbent in the visible andultraviolet spectrum have high fluorescent quantum yields thermic and photochemicalstability and high solubility in organic solvents[1] There are different synthetic routes to obtainBODIPY dyes[2] these differences are related to the need of obtaining symmetric orasymmetric compounds to add substituents in different positions of the BODIPY core and toreduce reaction times and solvent waste[3] The simplest route to obtain meso-substituteddyes is by acid-catalyzed condensation of two pyrrole units with an aldehyde unit

2 Experimental section21 Reagents and instrumentationCommercially available reagents and solvents were purchased from Sigma-Aldrich JTBAKER Acros Organics and Golden Bell and were used without further purification 1H NMR60MHz spectra was recorded using d-chloroform as internal standard with Eft-60 AnasaziInstruments spectrometer UV-Vis measurements were performed on Lambda 25 PerkinElmer spectrometer22 Synthesis221 General procedure for conventional and mechanochemical synthesis of BODIPY dyesConventional A solution of pyrrole (2eq) and the desired aldehyde (1eq) was dissolved in100mL of CH2Cl2 the system was purged with Argon in order to remove all the oxygen in theround flask a drop of trifluoroacetic acid was added as an acid catalyst and the mixture wasstirred for 3-12 hours or until a TLC experiment revealed the total consumption of the

Vol 1 Pag80

aldehyde Then 1 equivalent of DDQ was dissolved in 25mL of CH2Cl2 and was added dropwise then the reaction mixture was stirred for 15-30min Afterwards Et3N and BF3OEt2 (3mL each) were slowly added under an ice bath The reaction mixture was stirred for 3 hours The crude mixture was then washed with water and a saturated K2CO3 solution the organic phase was isolated and dried with Na2SO4 Purification was achieved by column chromatography in silica gel 4-Fluoro-8-(4-hydroxy-phenyl)-4H-4a-aza-3a-azonia-4-bora-s-indacene fluoride (2) Starting reagents were pyrrole (10 mmol 067 g) and 4-hydroxybenzaldehyde (5 mmol 061 g) oxidant was DDQ (5 mmol 1135 g) It was isolated as redbrown crystals Reaction yield 100 (0141 g 000049 mol) UV-Vis (λ nm) 497370 1H-NMR [600 MHz DMSO-d6] (δ ppm) 655 (m 2H H2) 691 (d J=247Hz H3) 702 (d 2H J=15Hz H4) 739 (d J=8Hz H5) 789 (d 2H H1) 4-Fluoro-8-pyren-1-yl-4H-4a-aza-3a-azonia-4-bora-s-indacene fluoride (4) Pyrrole (2 mmol 0134 g) and 1-Pyrenecarboxaldehyde (1 mmol 023g) DDQ (1 mmol 0227 g) as oxidant Product was isolated as cherry red crystals Reaction yield 84 (0035 g 836x10-5 mol) UV-Vis (λnm) 3434235071H-NMR [600 MHz CDCl3] (δ ppm) 810 (m 9H H4-5-6-7-8-9-10-11-12) 650 (d J=6Hz 6H H-1-2-3) Mechanochemical Pyrrole and aldehyde (21 eq) were added to a mortar Five drops of trifluoroacetic acid were added and the mixture grinded with a pestle for 1 minute Then 1eq of DDQ was added slowly with 2mL of CH2Cl2 the mixture was grinded for 1min After that 5mL of Et3N and BF3OEt2 were added and grinded for 1 minute Reaction control by TLC was done at all the previous steps The separation and purifying steps were the same as those of the conventional methodology Compound 4 was synthetized via mechanochemical methods as previously described Pyrrole (5 mmol 0335 g) and 1-Pyrenecarboxaldehyde (25 mmol 0575 g) DDQ (25 mmol 0567 g) as oxidant Product was isolated as a redbrown powder Reaction yield 32 (0031 g 7908x10-5 mol) UV-Vis (λnm) 3404245071H-NMR [600 MHz CDCl3] (δ ppm) 810 (m 9H H4-5-6-7-8-9-10-11-12) 650 (d J=6Hz 6H H-1-2-3) Table 1 Comparison between solvent and solvent-free methodologies

Reaction Steps

Condensation Oxidation Coordination

Solvent Solvent-Free Solvent Solvent-Free Solvent Solvent-Free

- Reaction time 2-12 h

- Preparation time 2 h

- Use of dry solvents

- Reaction time 1 min

- Preparation time 15 min

- No solvents

- Mitigate increase in viscosity by adding more

solvent

- Reaction time 30min

- Increase in viscosity makes grinding difficult

-Reaction time 1min

- Temperature control

- Closed System (N2 atmosphere)

- Highly pure BODIPY dyes

-Higher reaction yields

Reaction time 3h

- Lower reaction yields

and purity

- Canrsquot remove oxygen

Vol 1 Pag81

Figure 1 UV-Vis absorption spectrum for 2 and 4 dyes

3 Results and Discussion Table 1 describes a step-by-step comparison between the solvent and solvent-free methodologies used during this work The conventional method was all-around the best route to obtain highly pure BODIPY dyes the ability to maintain controlled atmosphere and replace all the oxygen present in the round flask with N2 is crucial to achieve the coordination between the boron and nitrogen BODIPY dyes were characterized by 1H-NMR and UV-Vis spectrum were obtained As shown in Figure 1 the UV-Vis spectrum of 2 and 4 were consistent with the typical BODIPY dye profile Compound 2 showed a high absorption peak at 497 nm which correspond to the S0-S1 transition and a shoulder of high energy at 475 nm which is caused by a 0-1 vibrational transition The second important signal on the UV region was found at 370 nm and is attributed to a S0-S1 transition since it lacks an additional chromophore to absorb in that region this band is clearly observed The molar extinction coefficient at the maximum absorption band (497 nm) was calculated with a value of 3806 M-1cm-1 Compound 4 presented two characteristic absorption bands BODIPY and pyrene For the BODIPY core two bands were observed One is an intense band at 507 nm which corresponded to a S0-S1 transition and the other one is a slight shoulder at 480 nm which is assigned to a 0-1 vibrational transition Two additional intense and wide absorption bands were observed at around 343 nm these ones are attributed to S0-Sn transitions in the pyrene unit that is attached to the meso-position of the BODIPY core This result is evidence that the two moieties (BODIPY-Pyrene) have no electronic interaction at ground state since absorption at 343 nm is not clearly distorted by the presence of BODIPY unit Optimization studies[4] demonstrate that the dihedral angle between the pyrene unit and the BODIPY core is 63 so that it not alters its planarity Thus the π-electronic clouds of both chromophores does not overlap and both system are independent of each other this explain why in the UV-Vis absorption spectrum appears as the sum of the parts of BODIPY core and Pyrene typical absorption spectrums The molar extinction coefficient at the maximum absorption band of the BODIPY core (507 nm) was calculated with a value of 136413 M-1cm-1 which give us evidence that this dye is highly absorbent at this wavelength this is important in applications such as sensitizers for solar cells

Vol 1 Pag82

BODIPY dye 1 could not be isolated we believe that the conditions in the oxidation step were too severe for 4-Hydroxy-3-methoxybenzaldehyde so the dipyrromethene was further oxidized to a quinone-like derivative BODIPY dye 3 could not be isolated however an interesting result was observed in the conventional route During the purification step a highly fluorescent compound was isolated as purple crystals UV-Vis absorption analysis revealed two important bands a strong and sharp band around 420 nm corresponding to a S0-S1 transition (Soret Band) and four small absorptions bands at around 550 nm (Q Bands) these correspond to a typical porphyrin absorption profile 4 Conclusions BODIPY dyes 2 and 4 were successfully synthetized via conventional methodologies using CH2Cl2 as solvent the reaction yields were 100 and 84 respectively 4 was the only dye that could be obtained via mechanochemical routes the reaction yield was about 32 The 1H NMR 60 MHz and UV-Vis spectra were obtained for all the isolated molecules Also the molar extinction coefficient for 2 and 4 was calculated with values of 3806 M-1cm-1 and 136413 M-1cm-1 respectively During the analysis of the UV-Vis spectra for compound 4 electronic interactions between the pyrene entity and the BODIPY core were not found in the ground state A comparison between solvent and solvent-free methodologies was done using reaction yields reaction times purity (as observed in a TLC experiment) and a variety of observations as criteria Conventional methodologies proved to be more efficient than their mechanochemical counterpart References 1 Loudet A Burgess K (BODIPY dyes and their derivatives Synthesis and Spectroscopic properties) Chem Rev 2007107 4891-4932 2 Lamarie P Dzyuba S (Expeditious mechanochemical synthesis of BODIPY dyes) Beilstein Journal of Organic Chemistry 2013 9 789-790 3 Valeur B (Molecular Fluorescence Principles and Applications) Wiley-VCH 2002ISBN 3-527-29919-X 4 Dehaen W Borggraeve W (Synthesis and applications of reactive BODIPY dyes) Doctoral Thesis Katholieke Universiteit Faculty of Science Netherlands 2010 3-8 Acknowledgements GZG thanks to National Science and Technology Minister (CB-2013-01 Project number 222847) and

Public Education Minister (F-PROMEP-39Rev-03) for financial support

Vol 1 Pag83

Behavior and Removal of Inclusions in a Funnel Mold in Thin Slab Continuous Casting Use of Mathematical and Physical Simulations

with the Aid of the Measured Vibrations with an Accelerometer Gerardo Barrera C1 Hugo Arcos G2 Carlos Espinosa2 Guillermo Carreoacuten G1

1Universidad Michoacana de San Nicolaacutes de Hidalgo Instituto de Investigacioacuten en Metalurgia y Materiales Morelia Mich Meacutexico gbarreraumichmx hcarreonumichmx

2Graduate Students Universidad Michoacana de San Nicolaacutes de Hidalgo Instituto de Investigacioacuten en Metalurgia y Materiales Meacutexico arcoshugogmailcom

Abstract Up to date there is little information available in the literature regarding the behavior of the inclusions especially inside the funnel type mold It has been found that the accelerometer is a transducer capable of relating the vibration with the behavior of the inclusions in the continuous casting mold It was indicated that higher levels of vibration in the thin slab mold are greater than the removal of inclusions therein Two nozzle designs two depths of 22 and 34 cm and three casting speed of 4 5 and 6 mmin were simulated In all cases just 100 particles were simulated within the flowing liquid metal because once the mathematical calculations or the processing time increases as the quantity of particles grow These have previously been treated with a liquid sensitive to the black light All cases were also solved in the simulation software Fluentreg where a slag layer in which all the inclusions that reach it are trapped The area near the nozzle has a greater concentration of particles which is due to low speed or flow pattern change in said zone These inclusions are eventually become stripped and trapped in the slag layer

KEY WORDS nozzle mathematical and physical simulation inclusions slag casting speed accelerometer and continuous casting mold

1 IntroductionThe present research work is focused on analysis of the behavior of inclusions in a thin slab continuous cast mold funnel type and observation of the possibility to eliminate them Physical and mathematical simulation is performed on the assumption with the redesign of a nozzle which is currently used in a Mexican company (Ternium) By varying both the depth of it and the casting speeds it was considered that greater removal of inclusions will possibly becomes within the liquid steel and then they will be trapped in the layer of lubricant powder (slag)

2 Experimental MethodologyThe experimental phase of this study was based on the analysis of the results of a previous mathematical modeling [16] both the nozzle and the mold for the continuous casting of thin slab funnel type The main goal of this research work will focus on the physical modeling

21 Physical Modeling A model of the mold and nozzle was designed based on the appropriate scale similarity criteria where liquid metal flow is simulated with water If the water flow in the model is a realistic representation of the actual flow in the mold it can be used to study various aspects of the flow into the mold including among others Deformation of the free surface and surface turbulence Viewing flow in different areas of the mold with a tracer Transport

Vol 1 Pag84

flotation and simulation of inclusions vorticity formation on the metal-slag interface and slag entrapment into the bosom of the liquid metal in the mold Energy dissipation etc

To study the behavior of the fluid flow a physical model a 12 scale of the actual mold continuous casting of thin slab funnel-like clear acrylic 12 mm thick was fabricated and a submerged entry nozzle SEN of complex geometry was manufactured in high density resin The mold was designed to work with a speed of up 8 mmin which is equivalent to 8434 litersmin of water

22 Vibration Monitoring The best way to visualize the performance of the continuous casting mold is monitoring it with transducers The main purpose of this work with the use of accelerometers is to follow the evolution of the flow pattern generated on one of the thin mold walls and also to correlate this pattern with the removal of inclusions in the mold in an indirect way The accelerometer signals are digitized with a DAQ card The accelerometer was placed at four different points Programs were written in graphical programming environment LabVIEWTM A signal pattern is taken and then natural noise of the system is subtracted numerically to the digitized transducer signal An area under the curve is calculated with the signal depending on the conditions of the simulation By this procedure depending on the casting it will be the magnitude of the signal

23 Inclusions Simulation Since the non-metallic inclusions in the liquid steel are lighter they can float to the surface For a range of sizes of inclusions reaching the continuous casting mold it can be assumed that the inclusions float according to the Stokes velocity law4) Using the relevant dimensionless numbers will reach to an equation in which the radius of the inclusion can be calculated with Eq (1) and by substituting the values of Table I in this equation a relationship between the radius of the prototype inclusion and model inclusion can be obtained from Eq (2)

1inc p

inc m inc pst

minus = minus

34174 25 (2)097411

inc m inc p inc pR R Rλ

minus = = minus

Table I Parameters for the calculation of model inclusions

Density of the inclusion model

(grcm3) Water density

(grcm3)

Density of the prototype inclusion (grcm3

Steel density (grcm3

Inclusion prototype

radius microm

0974 1 34 74 50-100

Using prototype inclusions ranging from 50 to 100 micros a calculation of the model inclusions was made based on Eq (2) The reason why the range used is that one most likely to be eliminated but smaller are almost impossible to remove Also this fact has a nothing-significant effect on the quality of the slab In table II the size distribution of the inclusions is shown

Table II Physical model parameters Velocity (mmin)

Water Flow (litersmin)

Inclusions Diameter (microm) Amount of particles per gram

4 49 250125 500 5 612 219211 730 6 734 110147 500

Vol 1 Pag85

24 Physical Simulation The cast speed flow of water the diameter and the amount of the inclusions per gram are presented in Table II Inclusions made with the acrylic material which was subjected to grinding classification and impregnation with penetrant inspection fluorescence dye Several black light lamps were placed around the mold and in the discharge area of the nozzle to observe more clearly the injected inclusions A digital camera to obtain images of the inclusions was used during its evolution into the mold and the slag simulated with industrial oil Because the amount of particles is huge for the purpose of this research work it was arrived to the conclusion that in this model 001 grams was enough to be in the range of 14000 to 40000 [5] particles as in the industrial prototype The depths in the model were 11 and 17 cm respectively The inclusions must be previously prepared with a dispersant in order to avoid any agglomeration Once the flow is leveled the particles are injected In order to know the removal ratio the inclusions are weighed and then a relationship is established with the injected ones It was very important in this stage to wash the inclusions to remove any oil traces in order to eliminate any error in the final weight Then is calculated the percentage of the removed inclusions

25 Results and Discussion The experimental results are analyzed in two stages the analysis of the vibration measurements and the inclusions removal in order to correlate the signals obtained with accelerometer and the behavior on the inclusions in the continuous casting funnel type mold A relationship between the vibrations and the speed casting was found and there is a directly proportional relationship between the increases in the intensity of the vibrations of the mold measured with an accelerometer This can be translated as a greater intensity of the vibrations that occurs due to higher energy dissipation in the model From the information obtained from the mathematical modeling phase a comparison is made of how the fluid behaves in the walls of the model in Fig 1 As it is expected for higher casting speed there is an increased flow velocity in the mold walls that it can be translated as a greater intensity of the vibrations that occurs due to greater energy dissipation in the model

Figure 1 Velocity profile at a line drawn at the mold narrow face and locations where the transducer was placed

Several graphs were done some of the results are shown in Fig 2 for a 200 s times at three different casting speeds 4 5 and 6 mmin and for both scales used in both the physical simulation superior part as in the mathematical simulation bottom part Thus being shown that the proposed transducer accelerometer not only can be used to detect changes in the flow pattern which is translated in the detection of the oscillations created by the jets from the nozzle ports and that impacts the thin steel layer solidified besides fluctuations in the steel-slag interface and in the prevention and correction of possible thread breakage This might lead to a higher productivity of the continuous casting process and improved control of it Also this can be taken as the start point to proof the relationship that exists between the

Vol 1 Pag86

removals of inclusions and the intensity of vibrations measured with the accelerometer This shows that the accelerometer is a device capable of detecting through its processed digital signal the energy generated in the mold of continuous casting of thin slab and it can be correlated with the elimination or removal of inclusions in it For experiments with casting speeds of 4 5 and 6 mmin to a depth of 22 cm nozzle some of the results are shown in Fig 3 as percentage of removal of inclusions

Figure 2 Intensity of vibrations and turbulent dissipation rate profile at a line drawn at the mold narrow face at a time of 200 s and locations where the transducer was placed for a) physical simulation and b) mathematical simulation

Figure 3 Comparison of percentage of entrapment of inclusions at 22 cm of deep physical model

Conclusions The mathematical and physical simulations as well as the vibration analysis have been proved to be very useful tools that can provide real and measurable values of the amount of energy in the mold and could be an indicative of how the inclusions are eliminated It was found that the accelerometer could be a transducer capable of correlate the intensity of the vibrations with the behavior of inclusions in the continuous casting mold Showing that at higher intensity of the vibration the higher amount of inclusions could be eliminated It also was found that the accelerometer could be used as a device to detect and prevent possible yarn breakage in the thin slab continuous casting machine

REFERENCES

Vol 1 Pag87

3) Y Murakata M G Sung K Sassa and S Asai ISIJ Int 47 2007 6634) Y Sahai and T Emi ISIJ Int 36 (1996) 11665) Q Yuan B G Thomas and S P Vanka Metall Mater Trans B 35B 2004 7036) H Arcos-Gutierrez G Barrera-Cardiel J de J Barreto and S Garcia-Hernandez ISIJ Int 2015

1) H Arcos and G Barrera Doctoral Work No 5 IIM UMSNH 2012 12) L Zhang S Yang K Cai and B G Thomas Metall Mater Trans B 38B 2007 63

Vol 1 Pag88

Comparative analysis of the CO2 capture properties for pure K- andNa-doped Li5AlO4

M Teresa Flores-Martiacutenez and Heriberto Pfeiffer

Instituto de Investigaciones en Materiales Universidad Nacional Autoacutenoma de Meacutexico Circuito Exterior sn Ciudad Universitaria Del Coyoacaacuten CP 04510 Meacutexico Ciudad de Meacutexico

trfloresunammx

IntroductionCO2 is the main anthropogenic greenhouse gas in the atmosphere One of the environmentimpacts of the large amount of CO2 in the atmosphere is the global warning and climatechange[1] Most efforts are focused mainly on reducing the amount of CO2 emitted to theatmosphere[2] Recently considerable high interest has been developed in the lithium-basedceramics and other alkaline elements due to their high CO2 absorption capacity at elevatedtemperatures Among these ceramics Li5AlO4 seems to be one of the best possible optionsas a CO2 capture material because of its high theoretical CO2

Previously some works have reported the CO

chemisorption capacity (159mmolg)[3]

2 chemisorption process on Na- and K-dopedlithium ceramics where the capture processes are increased considerably in comparisonwith their respective pristine ceramics This behavior has been explained because lithiumcarbonate formed during the CO2

This work describes the CO

chemisorption forms an eutectic mixture with eitherpotassium or sodium carbonates Thus the ceramic surface is partially fused favoring thediffusion processes[45]

2 chemisorption process in Kminus or Naminusdoped βminusLi5AlO4 systemsunder different thermal conditions Furthermore different CO2 sorption kinetic studies wereperformed on K- or Na-doped lithium aluminates and the reaction mechanism was evaluated

Experimental DetailsβminusLi5AlO4 was synthesized using a solid-state reaction that employs lithium oxide (Li2O) andgamma alumina (γminusAl2O3) It was characterized by X-ray diffraction (XRD) scanning electronmicroscopy (SEM) and N2 adsorption Doped powders of βminusLi5AlO4 were mechanicallymixed with 10 wt of potassium (K2CO3) or sodium (Na2CO3) carbonate These sampleswere labeled as mminusKminusβminusLi5AlO4 and mminusNaminusβminusLi5AlO4 respectively Additionally Naminus and Kminusdoped βminusLi5AlO4 samples were synthesized by a solid-state reaction adding 10 wt ofpotassium or sodium carbonate during the synthesis process In these cases the sampleswere labeled as sminusKminusβminusLi5AlO4 and sminusNaminusβminusLi5AlO4To determine the CO

respectively2 chemisorption capacity the Na and Kminusdoped lithium aluminates were

analyzed thermogravimetrically in the presence of dry CO2 Initially the samples weredynamically heated from room temperature up to 900 degC at 5 degCmin subsequently thesamples were tested isothermally at different temperatures (from 400 to 700 degC) under thepresence of a CO2 flow (60 mLmin) For the isothermal experiments the samples wereheated up to the corresponding temperature under a N2 flow Once the desired temperaturewas reached the gas flow was switched from N2 to CO2

Results and DiscussionThe formation of βminusLi5AlO4 was confirmed by X-ray powder diffraction (XRD data notshown) The surface area of ceramics with and without K or Na doping was determined using

Vol 1 Pag89

the BET model [6] The obtained values were considerably low (gt1 m2g) thus it wasassumed that they had no influence on the CO2

Initially the CO capture

2 chemisorption capacities of Na- and K-doped βminusLi5AlO4 were analyzedthermogravimetrically in the presence of a CO2 flux Figure 1 shows the dynamicthermograms obtained for Naminus and Kminusdoped βminusLi5AlO4 compared with the βminusLi5AlO4pristine These thermograms show two different processes taking place in the materials Thefirst one is a superficial CO2 chemisorption process occurring between ~200 and ~400 degCThen when the temperature was increased (gt500 degC) the diffusion processes wereactivated and the reaction continued through the bulk of the material completing the CO2chemisorption (Eqn (1)) Similar thermal trends have already been observed for other lithiumceramics [7minus9] Depending of the Na and K addition way two different trends were observed

Li5AlO4 (s) + 2 CO2 (g) 2 Li2CO3 (s) + LiAlO2 (s)

100 200 300 400 500 600 700 800 900

Temperature (degC)

βminusLi5AlO4

s-10K-βminusLi5AlO4

m-10K-βminusLi5AlO4

s-10Na-βminusLi5AlO4

m-10Na-βminusLi5AlO4

Figure 1 Comparative dynamic thermogravimetric analyses of Na- and K-containing βminusLi5AlO4

samples with pure βminusLi5AlO4 sample into a CO2

Then in order to analyze and understand the K- and Na-doping effects in βminusLi

5AlO4different and independent isothermal experiments were performed The CO2 chemisorptionof sminusKminusβminusLi5AlO4 showed an exponential behavior between 400 and 500 degC (Figure 2) Theeutectic mixtures should be produced at temperatures around to 550 degC improving the CO2diffusion-controlled chemisorption process Additionally it was possible to observe a doubleprocess occurring at 650 degC the first one taking place during the first minutes and thesecond one happening at longer times This isothermal behavior is consistent with theobservation of a double chemisorption mechanism mentioned above Finally theintercrystalline diffusion processes were activated at 700 degC improving even more the CO2

After the qualitative analysis the isotherms were fitted to a first-order reaction model withrespect to Li

chemisorption

5AlO4 (Eqn (1)) ln[Li5AlO4

where k is the reaction rate constant t is the time and [Li

] = -kt (2)

5AlO4] is the molar concentration ofthe ceramic (Figure 3)

Vol 1 Pag90

0 20 40 60 80 100 120 140 160 180100

400 degC450 degC500 degC

550 degC

650 degC

600 degC

Time (min)

700 degC

Figure 2 CO2 isotherms of sminusKminusβminusLi5AlO4

400 450 500 550 600 650 700

0025 βminusLi5AlO4

ln [Li5AlO4] =-k t

k (s-1

Temperature (degC)

at different temperatures

Figure 3 Comparison of plots of k versus Temperature for the data obtained at kinetic analysisassuming a first-order reaction of Li5AlO4

If the reaction is controlled by the interface movement from the surface inward it can bedescribed by the following equation 1-(1-α)

for short times

13 = kD

where α is the molar fraction of Lit (3)

2CO3 produced t is time and kD

Eyrings model is typically used on heterogeneous reactions and solidminusgas system to describe this kind of temperature dependence diffusion processes then k and k

is a constant whichdepends on the diffusion coefficient particle size and temperature (Figure 4)

D were toEyrings model ln(kiT) = -(∆HDaggerR)(1T) + lnE + ∆SDagger

Thus by means of fit the data obtained to a linear model the activation enthalpies (ΔHR (4)

Dagger)were calculated for both different processes (Tables 1 and 2) for at least two temperatureranges ΔHDagger values for CO2 direct chemisorption are lower in K- and Na-containing samplescompared to the βminusLi5AlO4 pure sample These values are higher for the kineticallycontrolled chemisorption processes It means that the direct chemisorptions process is lessdependent of temperature for doped samples than without doping In the kineticallycontrolled chemisorption case it could be observed the opposite behavior This implies thatthe direct chemisorption process is less temperature dependent than the chemisorptionprocess kinetically controlled by diffusion processes

Vol 1 Pag91

400 450 500 550 600 650 700

20x10-6

40x10-6

60x10-6

80x10-6

10x10-5

βminusLi5AlO4

kD t = 1-(1-α)13

k D (s-1

Temperature (degC)

Figure 4 Comparison of plots of k versus Temperature for the data obtained at kinetic analysisassuming a diffusion mechanism controlled by the interface movement from the surface inward

Table 1 activation enthalpies (ΔHDagger) for theCO2 direct chemisorption

Table 2 The activation enthalpies (ΔHDagger

Sample (450 - 650 degC)

) fordiffusion mechanism controlled by the

interface movement from the surface inwardΔHDagger (kJmol) Sample (400 - 550 degC) ΔHDagger (kJmol)

βminusLi5AlO 6904 βminusLi5AlO 3404

m-10K-βminusLi5AlO 4854 m-10K-βminusLi5AlO 5614

m-10Na-βminusLi5AlO 3024 m-10Na-βminusLi5AlO 11224

s-10K-βminusLi5AlO 6624 s-10K-βminusLi5AlO 6084

s-10Na-βminusLi5AlO 4354 s-10Na-βminusLi5AlO 7014

ConclusionIt was observed that the Na and K-doped βminuslithium aluminate in the process ofchemisorption of carbon dioxide at high temperatures present an improvement in the CO2capture process in the temperature range from 450 to 650 degC However the mechanicallydoped samples exhibit a great improvement in the CO2 capture temperature range from 500to 650 degC Thus the possible application of each sample may depend on the temperatureOverall the CO2 capture capacity from Na or K-doped βminusLi5AlO4 is good considering theirsmall surface area

References[1] DacuteAlessandro D M Smit B Long J R Angew Chem Int Ed 2010 49 2minus27[2] Qiang W Luo J Zhong Z Borgna A Energy Environ Sci 2011 4 42minus55[3] Aacutevalos-Rendoacuten T Lara V H Pfeiffer H Ind Eng Chem Res 2012 51 2622minus2630[4] Olivares-Mariacuten M Drage T Maroto-Valer M Int J Greenhouse Gas Control 2010 4 623minus629[5] Seggiani M Puccini M Vitolo S Int J Greenhouse Gas Control 2011 5 741minus748[6] Sing K S W Everett D H Haul R A W Moscou L Pierotti R A Rouquerol J Siemieniewska

T Pure amp Appl Chem 198557 603minus619[7] Mosqueda HA Vazquez C Bosch P Pfeiffer H Chem Mater 2006 18 2307minus2310[8] Palacios-Romero LM Pfeifer H Chem Lett 2008 37 862minus863[9] Duraacuten-Muntildeoz F Romero-Ibarra IC Pfeiffer H J Mater Chem A 2013 1 3919minus3925

AcknowledgementsThis work was financially supported by PAPIIT and SENER-CONACYT M T Flores-Martiacutenez thanks

PAPIIT and CONACYT for personal financial support

Vol 1 Pag92

Synthesis and characterization of Pr1-xCaxFeO3 (x = 01 03 y 05) thin films and measurement of its electrical conductivity

T Hernaacutendez L Madiacuten F J Garza MeacutendezUniversidad Autoacutenoma de Nuevo Leoacuten Facultad de Ciencias Quiacutemicas Laboratorio de materiales I CELAES Ciudad Universitaria Av Pedro de Alba SN

CP 66450 San Nicolaacutes de los Garza Nuevo Leoacuten Meacutexico Email tomashernandezgruanledumx

Abstract In the past few years a renewed interest has grown to study mixed perovskite oxides due to their potential for various applications such as catalysts cathode materials in solid oxide fuel cells magneto optics solar cells and sensor materials In this contribution Pr1-xCaxFeO3 (x = 01 03 and 05) thin films with perovskite-type structure were prepared using a modified sol-gel spin-coating method and electric conductivity was evaluated as an indication of their potential use as gas sensor The thermal decomposition of the precursors leads to the formation of Pr1-xCaxFeO3 thin film from a temperature of 650degC The structural morphological properties of the thin films were studied by X-ray diffraction (XRD) Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) The measurement of electrical conductivity of Pr1-xCaxFeO3 thin films were studied in this work The XRD analysis indicates the presence of Pr1-xCaxFeO3 in orthorhombic form in all the compositions The topography and roughness of the coating was obtained by AFM the morphology of the nanoparticles and the thickness of each composition around 190 nm were observed by SEM The partial substitution of Ca in the structure increases the conductivity of the thin film

Keywords perovskite oxides thin films solndashgel electric conductivity

Introduction In the big cities with pollution the presence of oxidizing gases and volatile organic compounds (VOCs) affect the ozone layer in the atmosphere causing various disorders and diseases become a serious problem for human life [1] This is one of the reasons why the gas sensors is an attractive area of research for the control of gas emissions in the automotive sector industrial safety (detection of combustible gases such as propane methane hydrogen etc) domestic (CO alarms in homes recreational vehicles) odor detection leak detection (toxic gases) environmental control (monitoring air quality ozone etc) smoke detectors and many technologies that generally require the detection of gases in the atmosphere [2] Among the different detection techniques employed to locate such harmful gases are solid state sensors due to their small size and ease of use [3] In recent years it has given much importance to the conservation of the environment and has been clear increasing the use of green technologies that contribute to sustainable development of countries trend and here is where the films of mixed oxides with type structure perovskite have acquired a very important role for the development of electronic devices Perovskites have an ABO3 stoichiometry one of the distinguishing characteristics of these compounds for other families of oxides is the wide variety of substitutions that can accept in their crystallographic structure position A in the centers of the cube it can be occupied by ions metal as La3+ Nd3+ Pr3+ Ca2+ moreover in the centers of the octahedra sites B can be occupied by small ions Co3+ Fe3+ consequently type perovskites are very versatile structures The modifications in the microstructure processing parameters and as well the concentration of the acceptordonor dopant may vary the temperature coefficient of resistance and conductivity of the oxides ABO3 [4] In literature you can find several methods of preparing perovskite films [5-7] in 2012 Nieto [8] prepared and characterized films of the system PrFe07Ni03O3 deposited on glass with thespin-coating technique temperature for the crystalline phase was 650 deg C It was observedthat the homogeneity of the films is affected by the deposition rate and the concentration ofpolyvinylpyrrolidone which helps decrease cracks in the film In 2014 Nieto [9] preparedsemiconducting films Sm1-xCaxFe07Co03O3 (x = 00 - 03) on glass substrate using the sol-gel

Vol 1 Pag93

method assisted by the spin-coating technique The maximum sensitivity values were obtained for films with more calcium to 300 deg C reaching 100 response these results showed that the properties of sensing films compared to CO and propane are improved by doping with Ca2+ in the site of Sm3+ In this context the present research provides information on the synthesis and characterization of thin films of Pr1-xCaxFeO3 (x = 01 03 y 05) and measuring its electrical conductivity and give a possible application as gas sensors

Experimental Section Preparation of Pr1-xCaxFeO3 (x = 01 03 05) system Stoichiometric amounts of Pr(NO3)3∙9H2O Ca(NO3)3∙4H2O Fe(NO3)3∙9H2O Citric acid and ethylene glycol were weighed these precursors were dissolved in 20 ml of polyvinylpyrrolidone (PVP) 10 prepared previously with constant stirring to homogenize the solution then the mixture was placed in a sand bath at a temperature of 70 degC Gel was obtained the resulting mixture then with the aid of a syringe was deposited on the glass substrate using a conventional spin coater at a speed of 3000 rpm substrates with the solution are heated in an oven for 40 minutes at a temperature of 120 degC Finally the films are taken out and placed in a muffle furnace for 2 h at 650 degC (see Figure 1)

Figure 1 Outline of procedure

Characterization The films were analyzed by X-ray diffraction (XRD) using a diffractometer for powder X-ray the topography of the films was observed using atomic force microscopy (AFM) thickness was measured with a profilometer the microstructure of the films obtained were analyzed by a scanning electron microscope (SEM) the current was measured with an amperemeter for measuring the conductivity of the films

Results and discussion The patterns of XRD low angle of the films Pr1-xCaxFeO3 (x= 01 03 and 05) system at 650 degC synthesized are shown in Figure 2 It can be seen that all peaks higher intensity are indexed in comparison with the compound of Pr09Ca01FeO3 The results of AFM show that the films exhibit good homogeneity and does not vary significantly between sample to sample because the samples were prepared in the same manner and were applied the same heat treatment to prevent superficial differences related to crystal growth due to temperature It can be seen in the films obtained at 650 degC agglomerates interconnected nanoparticles the structure is composed of a porous lattice of islands this behavior is characteristic of the perovskite Ohms law was used to measure the conductivity of the

Vol 1 Pag94

material at room temperature as we can see with increasing the amount of calcium in the sample exhibits better electrical properties

Figure 2 XRD patterns of the system Pr1-xCaxFeO3 (x = 01 - 05) at 650 degC by 2 h

Figure 3 The surface morphologies of films Pr1-xCaxFeO3 with a) x=01 b) x= 03 c) x=05 using AFM technique and surface morphology of film of Pr09Ca01FeO3 at different

magnifications a) 5000X b) 20000x c) 50000X using SEM technique

Table 1 Data from films Pr1-xCaxFeO3 system (x = 01 03 and 05) and the conductivity

Vol 1 Pag95

Conclusions The films Pr1-xCaxFeO3 (x = 01 03 05) with perovskite structure were synthesized without any impurities using citrate sol-gel method homogenous films of approximately 190 nm thickness is obtained by depositing 1 ml of the precursor solution at 3000 rpm spin velocity using the spin-coating technique and subsequent heat treatment at 650 degC for 2 hours It is observed that as the amount of calcium in the sample has better electrical properties By passing current through the films they present conductivity values so can be considered a material with potential use as gas sensor

Acknowledgments This study was carried out with financial support of UANL-PAICYT project IT 627-11

References 1 Pentildeuelas J y Lluisagrave J ldquoEmisiones biogeacutenicas de COVs y cambio global iquestSe defienden

las plantas contra el cambio climaacuteticordquo Ecosistemas 12 (2003) 1-72 Rosovsky H Narvaacuteez A Borges G Gonzaacutelez L ldquoEvolucioacuten del consumo per caacutepita en

Meacutexico Salud Mentalrdquo (1992) 35-43 Seiyama T Kato A Fujiishi K Nagatani M ldquoA new detector for gaseous components

using semiconductive thin filmsrdquo Anal Chem 34 (1962) 1502ndash15034 Ball J M Lee M M Hey A amp Snaith H ldquoLow-Temperature Processed

Mesosuperstructured to Thin-Film Perovskite Solar Cellsrdquo Energy Environ Sci 6(2013)1739ndash1743

5 Gao P-X Shimpi P Gao H Liu C Guo Y Cai W Liao K-T Wrobel G Zhang ZRen Z Lin H-J ldquoHierarchical assembly of multifunctional oxide-based compositenanostructures for energy and environmental applicationsrdquo International Journal ofMolecular Sciences 13 (2012) 7393-7423

6 Bhargav K K Ram S Labhsetwar Nitin Majumder S B Correlation of carboacuten monoxidesensing and catalytic activity of pure and catioacuten doped lanthanum iron oxide nano-crystalsrdquoSensors and Actuators B 206 (2015) 389ndash398

7 Peng Song Qi Wang Zhongxi Yang ldquoCO-sensing characteristics ofLa08Pb02Fe08Co02O3 perovskite films prepared by RF magnetroacuten sputteringrdquo PhysicaE 41 (2009)1479ndash1483

8 Nieto M ldquoPreparacioacuten de peliacuteculas de PrFe07Ni03O3 por la teacutecnica spin-coating conpolivinilpirrolidona (PVP) como aditivo de siacutentesisrdquo tesis licenciatura de quiacutemica industrialFCQ Junio 2012

9 Nieto M ldquoPeliacuteculas semiconductoras de Sm1-xCaxFe07Co03O3 preparacioacuten y estudio desus propiedades sensoras de COVsrdquo tesis maestriacutea en materiales FCQ Junio 2014

Vol 1 Pag96

NITRIC OXIDE (NO) DELIVERY FROM [RU(NO)] METAL COMPLEXES WITH SUBSTITUTED TERPYRIDINE LIGANDS

Pascal G Lacroix1 Joeumllle Akl1 Isabelle Malfant1 Isabelle Sasaki1 Patricia Vicendo2 Mireille Blanchard-Desce3 Norberto Farfaacuten4 Rosa Santillaacuten5

Valerii Bukhanko6 Zoiumla Voitenko6

1LCC- CNRS 205 rte de Narbonne 31077 Toulouse (France) pascallacroixlcc-toulousefr 2IMRCP-UPS 218 rte de Narbonne 31062 Toulouse (France)

3ISM-CNRS 31 cours de la Libeacuteration 33405 Talence (France) 4FQ-UNAM Ciudad Universitaria 04510 Meacutexico D F (Meacutexico)

5CINVESTAV del IPN Meacutexico DF Apdo Postal 14-740 07000 (Meacutexico) 6Univ T Shevchenko Volodymyrska Street 64 01033 Kyiv (Ukraine)

From NOON switch to NO delivery

Our interest for ruthenium nitrosyl ([Ru(NO)]) complexes raised during a long research effort aimed at finding new nonlinear optical (NLO) switches induced at the molecular level by the action of an additional property [12] for instance by an optically induced isomerization [3] However to be fully convincing this approach requires ensuring a high yield of isomerization in the solid state Along this line an exceptionally large yield of photo-switch was recently reported on a crystal of [RuII(py)4Cl(NO)](PF6)212 H2O (Scheme 1) in which more than 92 of the ruthenium-nitrosyl complexes can be successfully isomerized to ruthenium-isonitrosyl ([Ru(ON)]) bringing this optical material with intriguing switching capabilities [4]

Scheme 1

[RuII(py)4Cl(NO)]2+N

Ru N OClN

The last few years have witnessed an increasing interest for ruthenium-nitrosyl complexes Indeed the number of reports conducted from SciFinder on a literature survey at ldquoruthenium-nitrosylrdquo reveals that the number of publications on Ru(NO) has grown regularly since 1998 Interestingly while 40 of the entries are dedicated to ldquoNO isomerizationrdquo 60 are dedicated to ldquoNO releaserdquo

As we became aware of various technological limitations in the design of such molecular NLO switches (in relation to temperature effects) we became gradually more interested in NO release in relation to the numerous applications of nitric oxide in biology Importantly the action of NO strongly depends on its concentration (eg it favors cell proliferation at

Vol 1 Pag97

concentration ranges around 10-9 molL-1 with potential application in tissues building and tissues healing but it leads to scareless cell death at concentration around 10-9 molL-1 with potential application against cancer) [Ru(NO)] complexes have therefore emerged as especially promising because they are usually stable and well tolerated by the body and they can release the required amount of NO under irradiation exclusively Nevertheless [RuII(py)4Cl(NO)]2+ base species suffer from two inherent weaknesses for therapeutic applications (i) the lability of the pyridine in biological media and (ii) the need for an incident radiation in the λ = 300-500 nm range to release NO however out of the therapeutic window of transparency of the tissues (λ = 600-1300 nm) To overpass these difficulties the more robust [RuII(R-terpy)Cl2(NO)]+ in which R-terpy is a substitute terpyridine (Scheme 2) has been preferred for this investigation Furthermore the two-photon absorption (TPA) techniques in which 2 photons emitted at 800-1000 nm can be used instead of 1 photon at 400-500 nm has been envisioned There are additional advantages in using the TPAapproach such as the use of sub-pico laser pulses which provides no damages to the verylittle energy transferred to the cells and the highly focalized effects allowing to work cell percell without any collateral damages Fluorene has been selected as the first promising Rsubstituent (Scheme 2) It is indeed an electron-rich substituent which is usually engaged incharge transfer processes associated with large TPA capabilities

N ORR =

trans(ClCl)-[RuII(R-terpy)Cl2(NO)]+ cis(ClCl)-[RuII(R-terpy)Cl2(NO)]

fluorene

Scheme 2

trans(ClCl)-[RuII(FT)Cl2(NO)](PF6) and cis(ClCl)-[RuII(FT)Cl2(NO)](PF6)

The crystal structure of the resulting fluorenylterpyridine (FT) and related trans(ClCl)-[RuII(FT)Cl2(NO)]+ complex is shown in Figure 1 [5] The reduced torsion angle of 48deg observed between the fluorene the terpyridine suggests that a significant charge transfer could take place from the fluorene to the withdrawing Ru-NO fragment

Figure 1 Molecular crystal structures of FT (left) and trans(ClCl)-[RuII(FT)Cl2(NO)]+ (right) showing the internal torsion angles and the path of fluorene to Ru(NO) intramolecular charge transfer

Vol 1 Pag98

This possibility is further confirmed by the electronic properties investigated experimentally (Figure 2) and computationally by DFT (Figure 3) Both indicate the appearance of new transitions at low energy The dominant HOMO rarr LUMO contributions in these transitions indicate a strong intramolecular charge transfer from the fluorene to the Ru-NO fragment

Figure 2 UV-visible spectra and absorption maxima for FT (left) and [RuII(TF)Cl2(NO)](PF6) (right) The cis(ClCl) isomer is in blue the trans(ClCl) isomer is in red

Figure 3 HOMO (bottom) and LUMO (top) frontier orbitals and related charge transfer capabilities of FT (left) trans(ClCl)-[RuII(FT)Cl2(NO)]+ (center) and cis(ClCl)- [RuII(FT)Cl2(NO)]+ (right)

The possibility for NO release has been tested by one-photon absorption (OPA) at 405 nm for the cis and trans complexes in the presence of the Griess reagent which leads to the appearance of a pink dye at λ = 520 nm in the presence of free NO (Figure 4a) The quantum yield of photo-release is equal to 010 and 005 for the cis and trans derivatives respectively More importantly the TPA induced NO release has been evidenced by irradiation at λ = 810 nm ((Figure 4b)

(a) (b) Figure 4 NO release monitored by Griess test (a) UV-vis spectra with gradual appearance of

pink dye under OPA irradiation at 405 nm (b) NO release at the focal point under TPA irradiation at 810 nm

Vol 1 Pag99

Perspectives

The observation of TPA properties in the [Ru(NO)] complexes encourages the search for systems of enhanced capabilities While the precise quantification of the molecular TPA parameter (ldquomolecular cross-sectionrdquo σ) leads to a set of numerous intricate parameters offering no chemical clue to guide the experimentalist a two-level model leads to a simplified picture relevant I the case of ldquopush-pullrdquo chromophores [6]

120590120590 =161205871205872119891119891(120583120583119890119890119890119890 minus 120583120583119892119892119892119892)2

5ℏ1198881198882Γ times 119864119864 (Equation 1)

Within this model a restricted number of accessible parameters for each g rarr e transition (intensity f energy E and change in the dipole moment occurring during the transition microee ndash microgg) provide knowledge of the potential TPA response of the transition We have therefore identified the targets shown in Figure 5 with their relative computed σ values

Figure 5 Evolution of s values from equation 1 on the basis of possible substitutions performed on the FT ligand

References

[1] PG Lacroix I Malfant JA Real V Rodriguez Eur J Inorg Chem 2013 615-627[2] PG Lacroix I Malfant Ch Lepetit Coord Chem Rev 2016 308 381-394[3] J Akl Ch Billot PG Lacroix I Sasaki S Mallet-Ladeira I Malfant R Arcos-Ramos M

Romero N Farfan New J Chem 2013 37 3518-3527[4] B Cormary I Malfant M Buron-Le Cointe L Toupet B Delley D Schaniel N Mockus T

Woike K Fejfarova V Petricek M Dusek Acta Crystallogr Sect B 2009 65 612-623[5] J Akl I Sasaki PG Lacroix I Malfant S Mallet-Ladeira P Vicendo N Farfaacuten R Santillan

Dalton Trans 2014 45 12721-12733[6] F Terenziani C Katan E Badaeva S Tretiak M Blanchard-Desce Adv Mater 2008 20

4641-4678

Aknowledgements CONACyT CNRS ECOS-Nord action M11P01 Campus-France and the French embassy in Kiev

Vol 1 Pag100

STUDY OF GRAIN REFINEMENT IN ALUMINUM ALLOYS BY ADDING AL-TI-C AS GRAIN REFINER

GA Lara-Rodriacuteguez N A Hernaacutendez-Zalasar E-Hernaacutendez-Mecinas O Novelo-Peralta IA-Figueroa

Instituto de Investigaciones en Materiales Universidad Nacional Autoacutenoma de Meacutexico Av Universidad No 3000 Cd Universitaria C AP 70-360 04510 Meacutexico

DF Meacutexico E-mail laragabunammx

Abstract

In the present work small addition of nanometric carbon was added in Al- Ti alloys in order to obtain Al-Ti-025 C (in wt) alloys The alloys were prepared with an arc melting furnace and heat treated at 900degC for 30 min was carried out in order to produce Ti carbides The alloy with the TiC was cast using the melt spinning technique in order to obtain melt-spun ribbons (25 ms) The microstructural characterization was carried out using X Ray diffraction (XRD) scanning electron microscopy (SEM) The Al-Ti-C was added to 1100 aluminum alloys with the aim of obtaining grain refinement in cast ingot and then to study its effect over the aluminum-matrix microstructure

Keywords Al-Ti-C alloy Rapid solidification grain refinement

Introductions In the last years the aluminum-based alloys have been widely studied in order to improve their physical and mechanical properties The Al-Ti-C compound has been considered as potential grain refinement for aluminum and their possible application as structural materials at high temperature [1-4] This has been used as a grain refiner of aluminum and magnesium alloys The Al-Ti-C alloy exhibit particles of TiC which are precursors of nucleation during solidification In the present work the effect of the addition of nanocarbon on the microstructure Al-Ti -C alloy was studied

Experimental method A small addition of nanometric carbon was added to the Al-Ti binary alloy Figure 2(a) The alloy was prepared with an arc melting furnace and heat treated at 900degC for 30 min This heat treatment was carried out in order to produce Ti carbides After this the alloy with the TiC was cast using the melt spinning technique in order to obtain ribbon shaped samples Figure 2(b) These ribbons were prepared to investigate the effect of the small addition of nanometric carbon for both samples ie melts spun ribbons and as-cast alloy The speed of the cooper wheel was 25 ms and the atmosphere used was argon The microstructure of the rapidly solidified alloy was examined by means of scanning electron microscopy and X-ray diffraction The spherical homogenous particles of the refined TiAl3 and TiC were observed within the melt spun ribbons The as-cast microstructure of the alloy and melt spun ribbons were compared in terms of their size and shape of such TiAl3 and TiC compounds The raw material used was the commercial aluminum 1100 alloy and 05 wt of Al-Ti-C was added to

Vol 1 Pag101

the melt It is worth noting that the alloys were prepared in a graphite crucible using high frequency induction furnace The molten alloys were finally cast into a cooper mold to produce ingots of 20 mm X 150 mm

Figure 1 a) SEM Micrographs nanometric carbon b) Rapid solidification technique c) Cross section melts spun ribbons

Figure 2 Shows that the XRD patterns of melt-spun ribbons are composed of the phases α-Al TiAl3 and TiC The SEM microstructures of the Al-Ti-C melt-spun ribbons Fig 5 consist of needle shape morphology TiAl3 matrix a-Al and fine particles TiC embedded in α-Al which is in agreement with the XRD results Fig 1c

Figure 2 XRD Melt spun ribbons

Figure 3 show the macrostructure of melt aluminum 1100 and the alloy with the addition of Al-Ti-C There it was observed a columnar structure on pure aluminum cast ingot (Fig 3a) On the other hand Figure 3b displays the macroestructure with small addition of Al-Ti-C A significant differences have been observed on the microstructure The microstructural features of the AlndashTindashC additions to master alloys showed a big impact on the grain refining efficiency for the studied alloys

Free surface

Contact wheel

TiC α-Al

(a) (b) (c)

Vol 1 Pag102

Figure 3 Micrographs of a) As cast pure 1100 aluminum alloys b) 05 wt Al-5Ti-025C grain refinement

From the above it was also observed that there has been a slight decrement in the grain size The macro grain size was minimized to some extent with this grain refiner this is ascribed to concentration gradients in the liquid around the solidifying dendrites which retard crystal growth Besides the release of the heat of fusion allowed the interior of the casting to undercool forming new crystallites

Figure 4 SEM micrographs of microestructure of 1100 aluminium alloys a) As cast pure 1100 aluminum alloys b) Added 05 wt Al-5Ti-025C grain refinement

However a significant decrement on the micro grain size was not observed Figure 4 a-b shows the dendritic microestucture that was obtained The grain size refinement was found to be rather poor this could be attributed to the high amount of TiC particles which tended to agglomerate during the melting procces leading to a poor nucleation efficiency The mechanical properties of most cast alloys strongly depended on dendrite arm spacing (DAS) Further refinement may also lead to fine equiaxed structure [5]

Conclusions Al-Ti-025C (wt) alloys do macrograin refine 1100 aluminum alloys However a rather poorly grain refinement on microstructure was found It is possible that high number of TiC particles agglomerated during the melting stage leading to poor nucleation efficiency More research to achieve grain size refining to improve mechanical properties of aluminum alloys

(a) (b)

Vol 1 Pag103

to develop new manufacturing process like mechanical improvements in porous materials (metal foam) is needed

Acknowledgements This work done with the support of the UNAM-DGAPA-PAPIME Program No PE103416 The authors are grateful to A Tejeda JM Garcia for the technical support

References [1] Zhonghua Zhang Xiufang Bian Zhenqing Wang Xiangfa Liu Yan Wang Microstructures and grainrefinement performance of rapidly solidified AlndashTindashC master alloys Journal of Alloys and Compounds339 (2002) pp 180ndash188

[2] P S Mohanty and J E Gruzleski Mechanism of Grain refinement in aluminium Acta metalltaterVol 43 No 5 (1995)pp 2001-2012

[3] K T Kashyap and T Chandrashekar Effects and mechanisms of grain refinement in aluminiumalloys Bull Mater Sci (2001) Vol 24 No 4pp 345ndash353

[4] Berker T Gezer Fatin Toptan Sibel Daglilar Isil Kerti Production of Al-Ti-C grain refiners whit theaddition of elemental carbon Materials and Design (2010) Vol 31 S30-S35

[5] Bondan T Sofyan Daniel J Kharistal Lukfawan Trijati Kaspar Purba Ragil E Susanto Grainrefinement of AA333 aluminium cast alloy by AlndashTi granulated flux Materials and Design (2010)Vol31 S36ndashS43

Vol 1 Pag104

SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES USING EICHHORNIA CRASSIPES

Silva-G Angeacutelica Mariel1 Martiacutenez-G M Sonia Mireya1 Rosano-O Genoveva2 Schabes-R Pablo Samuel3

1 Instituto Tecnoloacutegico de Toluca 2 Universidad Popular Autoacutenoma del Estado de Puebla AC

3 Universidad Nacional Autoacutenoma de Meacutexico

INTRODUCTION In the nanomaterials field nanoparticles are materials in size between 1-100 nanometers in diameter In this size range these materials offer specific properties or different behaviors from the bulk material due to the number of edges corners shapes crystal structure etc [1] The nanoparticles are not compounds with well defined bonds they are clusters of stabilized atoms to avoid their agglomeration

Metallic nanoparticles have been synthesized using different chemical physical and biological methods [2] however alternative green methods that using plant extracts has emerged as an easy and viable alternative to avoid toxic by-products or expensive production costs [3] furthermore the plants extracts contain different constitutes like secondary metabolites or phenolic compounds this last one are used for the biosynthesis of silver nanoparticles [4] Therefore in the present study the synthesis of nanoparticles are using the water hyacinth (Eichhornia crassipes) which is an aquatic invasive plant as reducing agent for silver nanoparticles in the quantum dots scale in acid condition and different plant section (roots stems and leaves)

MATERIALS AND METHODS For the AgNP synthesis it was selected and collected 2m2 from water hyacinth from Chignahuapan lagoon located in Almoloya del Rio State of Mexico The plants were washed with water and separated in roots stems and leaves and dried at room temperature The water hyacinth sections were pulverized and washed with hydrochloric acid 01 N For the synthesis according to [5] 0125 g of the biomass from each plant section was placed into polyethylene tubes Subsequently deionized water buffer solution pH 4 and metallic solution of silver nitrate were added Between each addition the tubes were exposed to ultrasonic bath during 15 minutes and centrifuged for 30 minutes Finally the biomass was separated from the solution by filtration The silver nanoparticles formation was confirmed by UV-Vis spectroscopy at 200-800 nanometers and they were characterized by transmission electron microscopy (TEM) and high resolution (HRTEM)

RESULTS In the synthesis the plant solution was yellow-green color however after addition of silver nitrate the color was changed to brown The formation of silver nanoparticles in aqueous solution was confirmed using UV-Vis spectroscopy (Figure 1) The analysis was shown an absorbance peak around 430 nanometers which is the characteristic surface plasmon resonance for silver nanoparticles

Vol 1 Pag105

Figure 4 FFT patrons of HRTEM in leaves samples of AgO structure and a) hexagonal and b) triclinic bravais lattice

With transmission electron microscopy the silver nanoparticles images were analyzed in order to determine the shape size distribution structure and composition With the leaves samples were formed two different shapes cuboctahedron and icosahedron (Figure 2)

In the size distribution it was observed nanoparticles of 778 nanometers in diameter and 889 of total particles were in the quantum dots scale

With the interplanar spaces obtained from the Fourier Transform analysis it was found only an silver oxide phase with two bravais lattice hexagonal and triclinic (Figure 4)

In the nanoparticles prepared with stems the micrographs with HRTEM showed a cuboctahedron and cubic morphology In the suspension the nanoparticles were stabilized without aggregation with a mean of 139 nanometers The silver nanoparticles does not

m m 5 nm5 nm

5 10 20 30 40 50 600

Diameter (nm)

2 nm2 nm

a) (204)

5 nm5 nm

105deg25deg

250 300 350 400 450 500 550Ab

Wavelength (nm)

roots stems leaves

Figure 2 HRTEM of a silver nanoparticles with a) cuboctahedron and b) icosahedron shapes

Figure 1 UV-Vis spectra of AgNP synthesized

Figure 3 AgNP leaves synthesized a) micrography and b) size distribution

Vol 1 Pag106

show a uniform diameter however the production of silver nanoparticles smaller than 20 nanometers was predominantly but the quantum dots obtained were lower than leaves According to the International tables for Crystallography the particles were in silver oxide form with cubic and trigonal structure

In the synthesized nanoparticles using roots icosahedral and cubic truncated shapes were identified In the micrographs showed in the Figure 9 it was observed the 517 of the synthesized nanoparticles were in the quantum dots scale and their size distribution was consistent with the stems samples Also the nanoparticles were in AgO form with crystal systems hexagonal and triclinic

DISCUSSION

In this work the most important challenge was the study of the plant section influence and it was observed under actual experimental conditions with a real influence in the synthesized nanoparticles due to the plant section With all sections were produced silver nanoparticles in quantum dots but the higher percent was obtained using water hyacinth leaves with 889 while using stems and roots in the synthesis their size distribution was similar with high production of particles between 20 to 60 nanometers in diameter

In UV-Vis spectroscopy the most important change was in the nanoparticles synthesized with stems and it has been associated with the highest production of particles between 20-60 nm in comparison with roots and leaves and as the diameter increases the peak associated with the surface Plasmon resonance becomes more defined

The change of color in the solutions was not immediately in some of them as occurs in the biosynthesis using pH in a basic scale This condition has been associated with the pH influence during synthesis With acid pH an increase in the protons concentration occurs and it reduces the oxidizing ability to replace electrons increasing the particle size due the small particles collision

On the other hand the high resolution transmission electron microscopy analysis showed the single chemical form in the silver nanoparticles synthesized was silver oxide and the nanoparticles phase does not dependent from the water hyacinth section used during the biosynthesis process

CONCLUSION

The section used of water hyacinth in the biosynthesis of silver nanoparticles has not shown a real influence in the particles diameter The smallest particles were founded while the green sections were used and this may suggest that in these sections the production of secondary metabolites increase as a mechanism of defense and adaptation to the environment

The transmission electron microscopy and high resolution analysis showed silver nanoparticles in quantum dots as silver oxide phase and the shape and structure were not dependent of the water hyacinth section

Vol 1 Pag107

References

[1] Gaillet S amp Rouanet J (2015) ldquoSilver nanoparticles Their potential toxic effects after oral exposureand underlying mechanismrdquo Food and Chemical Toxicology No 77 pp 58-63

[2] Silva-de-Hoyos L Saacutenchez V Rico A Vilchis A Camacho M y Avalos M (2012) ldquoSilvernanoparticles biosynthesized using Opuntia ficus aqueous extractrdquo Superficies y Vaciacuteo Vol 25 No1 pp 31-35

[3] Rehab M amp Abuelmagd M (2014) ldquoRapid Green Synthesis of Metal Nanoparticles usingPomegranate Polyphenolsrdquo International Journal of sciences Basic and Applied Research Vol 15No 1 pp 57-65

[4] Prusty A amp Parida P (2014) ldquoGreen synthesis of Silver Nanoparticle Using Eichhornia and Studyof in-vitro Antimicrobial Activityrdquo Scholars Academic Journal of Pharmacy Vol 3 No 6 pp 504-509

[5] Rosano-Ortega G (2009) ldquoSiacutentesis de nanopartiacuteculas metaacutelicas mediante un procesoautosustentadordquo Tesis Doctoral Facultad de Quiacutemica Universidad Autoacutenoma del Estado de Meacutexico

Vol 1 Pag108

PHOTOLUMINESCENCE AND STRUCTURE TREND IN MIXTURE OF ZNO AND CARBON NANOPARTICLES DURING MECHANICAL

ACTIVATION

E Velaacutezquez Lozada1 T Torchynska2 M Kakazey3 M Vlasova3

1SEPI ndash ESIME ndash Instituto Politeacutecnico Nacional Ciudad de Meacutexico evlozada5yahoocommx 2ESFM ndash Instituto Politeacutecnico Nacional Meacutexico D F MEXICO

3CIICAp-Universidad Autoacutenoma del Estado de Morelos Cuernavaca MEXICO

Introduction ZnO nanocrystals (NCs) with the native defects or different type dopants are the one of most popular new systems (1) ZnO NCs with a direct band gap (337 eV) and a high exciton binding energy (60 meV) at 300K promises numerous applications in optical and electronic devices (1 2) such as catalytic materials (3) solar cells (4) field emission cathodes (5 6) luminescent materials (7) etc Important electronic properties have been revealed in the nanocrystalline composites ZnO + xC recently which permit improving the field emission properties of cathodes (5) engineering room-temperature ferromagnetism (8) modify luminescence properties (9) and to create the selective solar absorbed coatings (10) The creation of efficient electronic devices requires studying the emission nature and the mechanisms of defect generation in ZnO NCs In present paper the transformation of photoluminescence (PL) and its temperature dependences have been investigated for the mixture of ZnO + 10 C NCs with the goal to study the nature of PL bands the PL quenching mechanism the radiative defect nature and the process of defect creation at mechanical processing (MP)

Experimental details ZnO NCs (995 purity Reasol with the particle size of dZnO ~ 250 nm) and carbon nanoparticles (EPRUI Nanoparticles amp Microspheres Co Ltd) were mixed High resolution TEM images (performed earlier) have shown that the carbon nanoparticles are characterized by a spherical-like shape with an average diameter of dC ~ 50 nm Mechanical processing (MP) of ZnO + xC mixtures with x = 10 wt was carried out in a Planetary Ball-Mill (PM 4002 Retsch Inc) The grinding chamber of 50 ml with the tungsten carbide balls (3 of 20 mm and 10 of 10 mm) were used The weight ratio of balls to mixture powder equal to 281 has been used MP was carried out with the rotation speed 400 revmin for processing times (tMP) of 1 3 9 30 90 and 390 min The early X ray diffraction study has shown that the average ZnO NC sizes estimated using Sherrer formula (11) decreases from 250 nm in an initial state down to 14 nm for tMP = 390 min PL spectra were measured at 300K and the excitation by a He-Cd laser with a wavelength of 325 nm and a beam power of 46 mW using a PL setup on a base of spectrometer SPEX500 described in (1213) in the temperature range of 10-300K

Vol 1 Pag109

Experimental results and discussion PL spectra of the ZnO + 1 C mixture at 300 K measured for the different MP times are shown in figure 1

Figure 1 PL spectra of ZnO+1 C NCs at different moments of MP (a) 1-1min 2-3min (b) 1-3min 2-9min 3-90min 4-390min

It is clear that PL spectra are complex and can be represented as a set of PL bands The PL spectrum measured after 1 min of MP can be decomposed on three PL bands with the peaks at 314 eV (I) 242-250 eV (II) and 157 eV (III) (Fig1a curve 1) The UV and visible PL bands in ZnO NCs are attributed to the near-band-edge (NBE) (I) and defect related (II) emissions (14-18) NBE emission in ZnO NCs as a rule is related to the free or defect bound excitons with their phonon replicas andor the donor-acceptor pairs (1415) It was shown earlier in (1617) that free exciton emission or its replicas dominate in ZnO NC spectra at room temperature owing to the high free exciton binding energy (60 meV) at 300K and the fast decay of the PL intensities of bound exciton and donor-accepter pair emissions with increasing temperature in the range of 10-300K Thus the high PL intensity and a small half width of 314 eV PL band in PL spectra of the ZnO + 1 C mixture at 300K permit assigning NBE emission to the LO phonon replicas of free exciton emission in ZnO NCs The nature of IR PL band peaked at 157 eV (III) is not clear Note that in our experiments (presented below) this PL band intensity varies by the same way as the PL intensity of 314 eV PL band Thus we can attribute the IR PL band at 157 eV (III) to the second order diffraction peak of the 314 eV PL band (15-18) The PL intensity mentioned above PL bands decreases dramatically at MP and the new PL bands with peaks at 284 -295 eV 210-220 eV and 142-147 eV appeared (Fig 1b) The variation kinetics of the integrated PL intensities for all PL bands at MP are presented in figure 2 As it is clear there are two stages in this kinetics depending on the duration of MP process

Vol 1 Pag110

Figure 2 The variation of integrated PL intensities versus MP times for the PL bands1 -314 eV 2-157 eV 3-242 eV 4-211 eV 5-284 eV 6-142 eV

First stage The PL intensity decreases upon the first MP stage (1-9 min) with nearly the same rates for the NBE and defect related PL bands This effect can be assigned to the generation of non-radiative recombination centers (NR) at MP The PL intensity is proportional to the quantum efficiency (η) of visible recombination (19) The increase of NR center concentrations stimulates the rise of NR recombination rate together with falling down the PL intensity at MP Linear dependences of the PL intensity decay for the stage I presented in logarithmic scales (Fig 2) testify on the hyperbolic PL intensity variation versus time Note that NR centers can be assigned to the dangling bonds on the surface of ZnO NCs created at crushing the individual ZnO nanoparticles at MP Simultaneously in the first MP stage the peak of defect related PL band (II) shifts to 211-225 eV and the new PL bands peaked at 284-295eV and 142-147 eV appear (Figures 1b) Second stage The new PL bands with the peaks at 211-225 eV 284-295 eV and 142-147 eV dominate in the PL spectra of all samples after 9 min of MP (Figures 1b)The defects responsible for the 211-225 eV PL band can exist in the original ZnO NCs or their concentration can increase at MP as well The IR PL band peaked at 142-147 eV is attributed to the second order diffraction peak of 284-295 eV PL band The high energy PL band is characterized by the peak at 284-295 eV in the different samples of ZnO+1C NC mixture

Conclusion

The transformations of PL spectra and XRD diagrams in the ZnO NCs + 1C mixture at mechanical processing have been investigated Two stages of PL spectrum transformation have been revealed and discussed It is shown that the first stage is connected with the quenching of PL intensities of all PL bands owing to the nonradiative center appearing at crushing the individual ZnO NCs and decreasing their sizes from 250 nm down to 14nm The second stage of PL spectrum transformation at MP is connected with appearing the new 284-295 eV and 211-225 eV PL bands

Vol 1 Pag111

References [1] Zinc Oxide Fundamentals Materials and Device Technology Hadis Morkoccedil and Uumlmit

Oumlzgur 2009 WILEY-VCH Verlag GmbH amp Co KGaA Weinheim[2] Uuml Oumlzguumlr Ya I Alivov C Liu A Teke M A Reshchikov S Doğan V Avrutin H Cho S-J

Morkoccedil J Appl Phys 98 041301 (2005)[3] R Gurwitz R Cohen I Shalish J Appl Phys 115 033701 (2014)[4] Z Fan J G Lu J Nanosci Nanotechnol 5 1561 (2005)[5] N Pan H Xue M Yu X Cui X Wang J G Hou J Huang Nanotechnology 21 225707

(2010)[6] Won Il Park Jin Suk Kim Gyu-Chul Yi M H Bae and H-J Lee Appl Phys Lett 85

5052 (2004)[7] MA Reshchikov_ H Morkoc B Nemeth J Nause J Xie B Hertog A Osinsky

Physica B 401ndash402 358 (2007)[8] H S Hsu Y Tung Y J Chen M G Chen J S Lee S J Sun phys status solidi (RRL) 5 447

(2011)[9] Y Hu H-J Chen J Appl Phys 101 124902 (2007)[10] G Katumba L Olumekor A Forbes G Makiwa B Mwakikunga Sol Energy Mater Sol

Cells 92 1285 (2008)[11] HP Klug LE Alexander X-ray Diffraction Procedures for Polycrystalline andAmorphous Materials Wiley and Sons NewYork 1974[12] T V Torchynska M Dybiec S Ostapenko Phys Rev B 72 195341 (2005)[13] N Korsunska L Khomenkova M K Sheinkman T Stara V Yuhimchuk T V

Torchynska A Vivas Hernandez J Lumines 115 117 (2005)[14] AB Djurišic AMC Ng XY Chen Progress in Quantum Electronics 34 191

(2010)[15] T V Torchynska and B El Filali J of Lumines 149 54 (2014)[16] AI Diaz Cano B El Filali TV Torchynska JL Casas Espinola Physica E 51 24

(2013)[17] E Velaacutezquez Lozada TV Torchynska J L Casas Espinola B Perez Millan and L

Castantildeeda Physica B 453 111 (2014)[18] AI Diaz Cano B El Falali TV Torchynska JL Casas Espinola J Phys

Chem Solids74 431 (2013)[19] TV Torchynska Physica E 44 56 (2011)

Vol 1 Pag112

ALUMINUM CONCENTRATION AND SUBSTRATE TEMPERATURE ON THE PHYSICAL CHARACTERISTICS OF CHEMICAL SPRAYED

ZNOAL THIN SOLID FILMS

E Velaacutezquez Lozada1 L Castantildeeda2 G M Camacho Gonzaacutelez3

1SEPI ndash ESIME ndash Instituto Politeacutecnico Nacional Ciudad de Meacutexico evlozada5yahoocommx 2ESIME ndash Instituto Politeacutecnico Nacional Ciudad de Meacutexico MEXICO 3ESIME ndash Instituto Politeacutecnico Nacional Meacutexico D F 07738 Meacutexico

Abstract Chemically sprayed aluminium-doped zinc oxide thin films (ZnOAl) were deposited on soda-lime glass substrates starting from zinc pentanedionate and aluminium pentanedionate The influence of both the dopant concentration in the starting solution and the substrate temperature on the composition morphology and transport properties of the ZnOAl thin films were studied The structure of all the ZnOAl thin films was polycrystalline and variation in the preferential growth with the aluminium content in the solution was observed from an initial (002) growth in films with low Al content switching to a predominance of (101) planes for heavily dopant regime The crystallite size was found to decrease with doping concentration and range from 33 to 20 nm First-order Raman scattering from ZnOAl all

having the wurtzite structure 46vC The assignments of the E2 mode in ZnOAl differ from

previous investigations The film composition and the dopant concentration were determined by Auger Electron Spectroscopy (AES) these results showed that the films are almost stoichiometric ZnO The optimum deposition conditions leading to conductive and transparent ZnOAl thin films were also found In this way a resistivity of 003 Ω-cm with a (002) preferential growth were obtained in optimized ZnOAl thin films

Experimental details ZnO thin solid films were synthesized by the ultrasonic spray pyrolysis technique The chemical preparation started from zinc acetate dehydrated (Zn(CH3CO2)2 Sigma Aldrich 9999 ) dissolved in 50 mL of acetic acid ([CH3CO2H] from Baker 98) to obtain a concentration of 2 M solution Then the aforesaid solution was dissolved with certain amounts of methanol ([CH3OH] from Baker 98) and deionized water to adjust the final concentration of the precursor to 01 M The volume fraction of water in the solution was varied in the following way 001 005 and 015 In order to get the complete dissolution of the components the solution was stirred for 20 minutes prior to spraying process Alumina (Al2O3) substrates were cleaned prior to deposition The cleaning process of the substrates is as follows (i) sonication for five minutes in Extranreg - Formaldehyde-free AP 33 (from Merck Millipore) followed by (ii) sonication for five minutes in trichloroethylene ([C2HCl3] JT Baker 98 ) for degreasing the substrates then (iii) sonication in methyl alcohol ([CH3OH] Aldrich 98 ) (iv) sonication in acetone ([CH3COCH3] JT Baker 98 ) and finally (v) the substrates are dried under a flow of dry pure nitrogen (N2 PRAXAIR 99997 )

Vol 1 Pag113

Prior to deposition interdigitated electrodes were deposited on the alumina substrates by vacuum thermal evaporation of gold (wire 05 mm diam 9999 Aldrich) through a metallic mask A separation between the electrodes fingers of approximately 11 mm with a thickness of 15 μm was kept in order to get a maximum specific area (surface areavolume ratio) as shown on Figure 1 Afterwards using ultrasonic spray pyrolysis ZnO thin solid films were deposited through a stainless steel mask on the interdigitated electrodes

Fig 1 Schematic representation of the interdigitated electrodes that were deposited on the alumina substrates Substrates were prepared by vacuum thermal evaporation of gold (scale in cm)

Then for the deposition process the substrates were placed on a molten tin bath The cleaned substrate was preheated to 400ordmC this temperature was measured just below the substrate using a stainless steel jacket chromel-alumel thermocouple within an accuracy of plusmn1 degC During deposition pure N2 (from PRAXAIR 99997 ) was used as the precursor solution carrier and director gas with flow rates of 35 and 05 Lmin respectively The deposition system used in this work is equipped with a variable frequency piezoelectric transducer which was set to 14 MHz and operated at 120 W In the ultrasonic spray pyrolysis system micrometric droplets are formed by the action of a beam of ultrasonic vibrations coming from the atomizer The carrier gas transports and directs the formed spray droplets toward the surface of a hot substrate wherein the film growth takes place By following these experimental conditions the starting solutions were sprayed with a solution flow rate of 1 mLmin over the hot substrates The experimental setup used for the fabrication of the samples in this work is schematically presented in Figure 2

Vol 1 Pag114

Fig2 Experimental growth diagram

References [1] K Hyo-Joong L Jong-Heun Sensor Actuat B-Chem192( 2014) 607[2] G F Fine L M Cavanagh A Afonja and R Binions Sensors 10 (2010) 5469[ 3] A Wei L Pan W Huang Mat Sci Eng B-Solid 176 [18] (2011) 1409[4] A Gonccedilalves A Pimentel P Barquinha G Gonccedilalves L Pereira I Ferreira RMartins Appl Phys A 96 (2009) 197[5] B Fabbri A Gaiardo A Giberti V Guidi C Malagugrave A Martucci M Sturaro GZonta S Gherardi P Bernardoni Sensor Actuat B- Chem ( 2015)[6] A Forleo L Francioso S Capone P Siciliano P Lommens Z Hens SensorActuat B-Chem 146 ( 2010) 111[7] Y Wang H L Wang C-Q Liu Y Wang S Peng W P Chai Mater Sci SemiconProc 15 (2012) 555[8] O D Jayakumar and A K Tyagi Int J Nanotechnol 7 (2010) 1047[9] MA Boukadhaba A Fouzri V Sallet SS Hassani G Amiri A Lusson MOumezzine Superlattice Microst 85 ( 2015) 820[10] NH Sheeba Sunil C Vattappalam J Naduvath PV Sreenivasand M Sunny RR Philip Chem Phys Lett 635 (2015) 290

Vol 1 Pag115

TiO2 NANOPARTICLES SENSITIZED WITH MICROWAVE-AFFORDED Ru(II) COMPLEXES TO INVESTIGATE THE PHOTOPHYSICAL RESPONSE OF

ANTENNA-COMPLEXES IN DSSC SOLAR CELLS Jorge S Gancheff1 Karolina Soca1 Florencia Luzardo1 Rauacutel Chiozzone1 Pablo A Denis2Paula Enciso3 M Fernanda Cerdaacute3 Reza Dousti4 Andrea S S de Camargo4 1Caacutetedra de Quiacutemica Inorgaacutenica Departamento Estrella Campos Universidad de la Repuacuteblica Av Gral Flores 2124 11800 Montevideo URUGUAY E-mail jorgefqeduuy 2Computational Nanotechnology DETEMA Universidad de la Repuacuteblica Montevideo URUGUAY 3Laboratorio de Biomateriales Facultad de Ciencias Universidad de la Repuacuteblica Montevideo

URUGUAY 4Satildeo Carlos Physics Institute University of Satildeo Paulo Satildeo Carlos SP 13566-590 Brazil

Abstract The technology of converting sunlight into electricity has recently emerged as animportant strategy aimed at achieving a sustainable diversification of the energy matrix inUruguay and other South American countries In this regard photovoltaic devices appearquite attractive because they are noiseless present no carbon dioxide emission and requirerather simple operation and maintenance those of solid-state junction mdashusually made ofsiliconmdash being the most important ones This technology which is associated with importantcosts has been challenged in the last few years by the development of a third-generationsolar cells based on conducting polymers films and nanocrystalline oxides The so-called dye-sensitized solar cells (DSSC) appear as a representative prototype of this family ofphotovoltaic devices They combine the optical absorption and the charge separationprocesses by association of a sensitizer mdashas the light-absorbing materialmdash with a wide band-gap semiconductor of nanocrystalline morphology Herein photophysical investigations of a Ru(II) novel complex (synthetized by eco-friendly methods) of potential application as antenna in DSSC are presented The studies cover the response of the isolated complex in the solid state and in solution In order to have a clearpicture of the influence of the sensitization process on the photophysical properties ofcomplexes absorptionphotoluminescence studies of TiO2 (anatase) nanoparticles mdashalsoprepared by microwave-assisted reactionsmdash sensitized with the Ru(II) complex are alsoincluded To get deeper insight into the electronic features of all systems DFT calculations atthe B3LYPLANL2DZ level of theory have also been conducted

Vol 1 Pag116

The technology of converting sunlight into electricity has witnessed an enormous growth in the lastfew years Solar cells have been used in different applications ranging from small consumerelectronics to megawatt-scale power plants [1] Direct use of solar radiation to produce electricity isperceived as an almost ideal way to employ natureacutes renewable energy Despite the significantdevelopment over the past decades the high cost of solar cells remains a limiting factor for themassive implementation of solar electricity on a larger scale [2] In contrast to conventional silicon-based semiconductor solar cells the dye-sensitized solar cell (DSSC) technology which comprises aphotochemical solar cell has emerged as an important alternative in the last few years Since thenmany scientists have focused on the development of new and most efficient dyes One of the mostimportant concerns with the synthesis of dyes for DSSCs is the use of harmful organic solvents Asolution to this drawback has been proposed by introducing a microwave-based synthetic approachemploying eco-friendly solvents Herein we present the synthesis and a spectroscopic investigation of a new Ru(II) complex of potential application in DSSC prepared by microwave-assisted reactions in water as a benign solvent Then TiO2 (anatase) nanoparticles also synthetized by microwave irradiation were sensitized withthe Ru(II) complex to study the photophysical behavior of dyes in DSSC conditions Theoretical (DFTand TD-DFT) calculations have also been performed to shed light into different electronic aspects ofthe isolated and the attached dye The reaction path used to prepare the new Ru(II) complex involved the use of [RuCl2(p-cymene)2]2 and cis-[RuCl2(dcbipy)2] as precursor The microwave-assisted synthetic strategy employed to obtain [RuCl2(p-cymene)2]2 and cis-[RuCl2(dcbipy)2] allowed us to reproduce the results of Toumlnnenmann etal [3] and Kristensen et al [4] respectively At the same time it prompted us to implement theabovementioned strategy as a routine synthetic tool in our Inorganic Chemistry laboratory Thus wedecide to prepared a new Ru(II) complex mdashpotential antenna in DSSCmdash by using MW irradiation inwater The combination of cis-[RuCl2(dcbipy)2] and isonicotinic acid in inert atmosphere led to theformation of cis-[Ru(dcbipy)2(ina)2]Cl2 (Ru-ina Scheme 1) When the reaction proceeded in anoxidative atmosphere we detected signals of metal oxidation (UVndashVIS) The formation of the cisisomer was ensured by the use of a temperature above 170 degC as stated by Kristensen et al inpreparing cis-[Ru(NCS)2(dcbipy)2] using MW tools [3]

Scheme 1 Microwave-assisted synthesis of Ru(II) complexes The Ru-ina complex was characterized by FTndashIR and absorption photoluminescence spectroscopiesThe vibrational data show the asymmetricsymmetric bands for the carboxylic groups ndashCO2ndash at 17311607 1542 1385 cmndash1 and the characteristic pyridyl unit at 1385 cmndash1 Two absorption bands weredetected in the visible region centered at 489 nm (asymmetric band) and at 369 nm both of themexhibiting almost equal intensity Emission studies mdashexciting the complex with light of wavelength of500 nmmdash lead to a band peaked at 550 nm This result is in line with the behavior of the well-knownand so-called N3-sensitizer (cis-[Ru(NCS)2(dcbipy)2]) which was taken (in this work) as a model Inthis case an emission band centered at 545 nm (exc = 480 nm) was observed It is worth highlighting

Vol 1 Pag117

that N3 was prepared by microwave irradiation (Scheme 1) according to the one made available by Kristensen et al [4] The microwave-assisted technique was also applied to prepare TiO2 nanoparticles (anatase) according to the protocol of Moura et al [5] which were sensitized with the N3-model complex and with the new Ru(II)-complex This process was accomplished by immersing the white nanoparticles inan ethanolic solution of the complex during 24 h in the absence of light Pink nanoparticles wereobtained which indeed remained colored even after several washes with ethanol This observationpoints to a covalent anchoring of the dye to the semiconductor This result is not surprising sincecarboxylic groups are one of the most employed and effective anchoring groups of dyes in DSSC [67] Luminescence investigations of the sensitized nanoparticles with the model dye (system N3TiO2) revealed the presence of an absorption band at 530 nm red-shifted (+30 nm) with respect to the free-complex This result is in line for instance with the shift exhibited by N3 sensitizing Bi4Ti3O12nanoparticles [8] At the same time the luminescence measurements show an emission band at 541nm (exc = 500 nm) slightly blue-shifted (ndash4 nm) with respect to the free-dye When the sensitization process involves Ru-ina similar findings were obtained The UVndashVIS spectrum of (Ru-ina)TiO2 (Fig1) exhibits two absorption bands a 315 nm and 502 nm the last one being measured +13 nm with respect to the isolated dye DFT and TD-DFT calculations were performed for cis-[RuX2(dcbipy)2] (Xndash = NCSndash Clndash) and for cis-[Ru(dcbipy)2(ina)2]2+ [9] In particular TD-DFT emission calculations in the presence of EtOH assolvent have been carried out for cis-[Ru(Cl)2(dcbipy)2] [9] This complex was used as an example totest the reliability of the theoretical tool in reproducing emission data and in doing that to implement this theoretical tool in our Theoretical Chemistry Laboratory While emission bands at 440 nm (exc of 340 nm) and at 540 nm (exc of 480 nm) have been experimentally detected for an ethanolic solution of cis-[Ru(Cl)2(dcbipy)2] two bands at 478 nm (exc of 396 nm) and at 527 nm (excof 456 nm) have been calculated with B3LYPLANL2DZC-PCM These results evidenced that this simple methodology is reliable enough to study different electronic aspects of dyes mdashpotentialantenna in DSSCmdash with a reasonable computational cost For Ru-ina TD-DFT absorption data (Fig 1) are available no emission theoretical results were obtained so far The simulated UVndashVIS spectrum [9] in ethanol was in reasonable agreement with the experimental evidence The excitations responsible for the band in the visible region involve startingMOs of mainly metallic character while destination MOs are located on ligands (dcbipy and ina) (Fig1) These results helped us to infer the origin of the band experimentally observed at 502 nm for (Ru-ina)TiO2 as metal-to-ligand charge transfer (MLCT) The band in the high-energy part of thespectrum (315 nm) seems to present the same origin (MLCT) with the electronic density movingfrom a metal-centered MO to a MO mainly located on the bipyridyl unit of the dcbipy anchoringligands It is worth mentioning that the sensitization process promoted an increase of the intensity ofthis band with respect to this band in the free-complex As aforementioned the contour ofdestination MO in the MLCT band at 315 nm displays charge delocalization on the bipyridyl unit ofthe dcbipy ligands This finding suggests that the carboxyl groups which act as a linkage group arethe ones located on the dcbipy ligands and not those of the ina ligand To confirm this assumptiontheoretical investigations of different electronic aspects of the Ru-inaTiO2 system at the DFT levelof theory are undertaken In conclusion the microwave-assisted tool has been successfully employed in yielding model Ru(II)antenna-complexes in DSSC At the same time it has proven to be adequate and eco-friendly toprepare new Ru(II) compounds In this line the complex cis-[Ru(dcbipy)2(ina)2]Cl2 has been obtainedand characterized It has been used to sensitize the surface of TiO2 (anatase) nanoparticles whichhave also been afforded by microwave techniques Luminescence studies of the new Ru(II) complex

Vol 1 Pag118

lead to results in line with the ones obtained for model complexes which point out that the newcomplex present potential application as antenna in DSSC The sensitization of the semiconductorsurface does not significantly change the photophysical features of the attached dye With assistanceof theoretical (DFT) calculations the sensitization of nanoparticles could be a reasonable model tostudy different electronic aspects of dyes in DSSC operative conditions

Figure 1 TD-DFT result of (Ru-ina) (dashed line) and experimental UVndashVIS spectrum of Ru-inaTiO2 (solidline) Most important MOs involved in the origin of the simulated bands for Ru-ina are also included References [1] F Dinccediler Renewable Sustainable Energy Rev 2011 15 713 [2] B Oregan M Graumltzel Nature 1991 353 737 [3] J Toumlnnenmann J Risse Z Grote R Scopellitu K Severin Eur J Inorg Chem 2013 4558[4] S H Kristensen J Toster K S Iyer C L Raston New J Chem 2011 35 2752 [5] K F Moura J Maul A R Albuquerque G P Casali E Longo D Keyson A G Souza J R Sambrano I M G Santos J Solid St Chem 2014 210 171 [6] L Zhang J M Cole ACS Appl Mater Interfaces 2015 7 3427 [7] A Hagfeldt G Boschloo L Sun L Kloo H Pettersson Chem Rev 2010 110 6595 [8] Z Chen S Li W Zhang Int J Photoenergy 2011 1155 [9] a) Geometry optimizations were performed at B3LYPLANL2DZ level of theory The nature of the stationarypoint was verified through a vibrational analysis (no imaginary frequencies at the minimum) The Time-Dependent DFT (TD-DFT) methodology was employed to calculate one hundred spin-allowed transitions in the gas phase and in the presence of the solvent (EtOH) The excitations responsible for the absorption

bands were taken as exc in emission calculations which were also conducted in the presence of thesolvent All effects of solvent were described by the conductor-like polarizable continuum model (C-PCM)[9bc] While all calculations have been conducted by using Gaussian09 (Rev D01) [6d] electronic UV-VISspectra were simulated by means of the GausSum software [6e] b) V Barone M Cossi J Phys Chem A1998 102 1995 c) M Cossi N Rega G Scalmani V Barone J Comput Chem 2003 24 669 d) M JFrisch et al Gaussian Inc Wallingford CT 2009 e) N M OacuteBoyle A L Tenderholt K M Langner J CompChem 2008 29 839 Acknowledgements This work was supported by Agencia Nacional de Investigacioacuten e Innovacioacuten (ANII Proy FSE_1_2011_1_6156) We are also indebted to PEDECIBA-Quiacutemica ASSC would like to thank FAPESP (Fundaccedilatildeo de Amparo agrave Pesquisa do Estado de Satildeo Paulo Brazil) for the financial support (Cepid Project 201307793-6)

Vol 1 Pag119

CCC-NHC Tantalum Bis(imido) Reactivity Protonation orRearrangement to a Mixed

Unsymmetrical CCC-N-Heterocylic CarbeneN-Heterocyclic Dicarbene (CCC-NHC-NHDC)

Pincer Tantalum Bis(imido) Complex

T Keith Hollis1 T Keith Hollis1Theodore R Helgert 12 Charles Edwin Webster1 HenryU Valle12 Allen G Oliver3

1Department of Chemistry Box 9573 Mississippi State University Mississippi State Mississippi 39762-9573 United States khollischemistrymsstateedu

2Department of Chemistry and Biochemistry The University of Mississippi University MS 38677 United States

3Department of Chemistry and Biochemistry University of Notre Dame Notre Dame Indiana 46556 United States

Abstract The coordination sphere of the reported (13-bis(3-butylimidazol-1-yl-2-idene)-2-phenylene) (tert-butylimido) CCC-NHC Ta (V) bis(imido) pincer complex 1 (Helgert et al Organometallics 2016 DOI 101021acsorganomet6b00216) has been has been observed to spontaneously rearrange to yield X-ray quality crystals of a CCC-NHDCNHC pincer Ta (V) bis(imido) complex (2) Over time CCC-NHC Ta (V) bis(imido) pincer complex 2 reacts with adventitious protons sources to form (BuCiCiCBu)Ta(V)(tert-butylamido)(tert-butylimido)iodo complex (4)

Introduction

The seminal work of Bertrand and Arduengo has shown that carbenes are not the transient intermediates chemists once believed [1] but persistent and isolable carbon species In particular N-heterocyclic carbenes (NHCs) have become ever-present in late-transition-metal chemistry[2] yet the study of early-transition-metal NHCs is still in its infancy[1c] In particular Ta NHC complexes are rare Only eight Ta NHC complexes have been reported to date[3] Due to the popularity of NHCs as ancillary ligands for new metal complexes studies into NHC variants have become a new and expanding field of research[4] One noteworthy NHC derivative is the imidazole-base-NHC bound to a metal via the backbone C-4 or C-5 carbons known as a mesoionic carbene (MIC) or abnormal carbene Crabtree reported the first MIC complex in 2001[5] and the first free MIC was reported by Bertrand in 2009[6] MICsabnormal carbenes are interesting since they are better σ-donors than their C-2 bound NHC equivalents The increased σ-donor ability is due to the presence of only one adjacent heteroatom which decreases the inductive effect on the carbene[7] Robinson has further expanded alternative binding by imidazole-based-NHCs with his recent report of imidazole ring containing simultaneous carbene centers at the C-2 and C-4 (or C-5) positions known as the anionic N-heterocyclic dicarbene (NHDC)[8] Current research on NHDCs is primarily focused on mid-to-late-transition-metals NHDC complexes and the reaction of NHDCs with

Vol 1 Pag120

small molecules such as BH3 CO2 SiCl4[9] To date only one report of early-transition-metal Sm and Y NHDC complexes by Arnold is found in the literature[10]

Chart 1 Imidazole based N-heterocyclic carbenes (Arduengo) meso-ionic carbenes or abnormal-N-heterocyclic carbenes (Bertrand) and Anionic N-heterocyclic dicarbenes (Robinson)

The pincer ligand architecture is a favorite motif for ligand design that has been research intensely since it was first reported in the 1970rsquos This architecture offers a facile alteration of the metal center by modification of the donor groups prior to the synthesis of the complex Manipulation of the pincer ligand after complexation has been reported and is often the deprotonation of a spacer group between donors[11] Incorporation of NHCrsquos in pincer ligands has been of increasing interest and is an efficient route to synthesize stable early-transition-metal NHC complexes[3a 3c 12] Pincer ligands containing NHDCs nor the rearrangement of an NHC within a pincer ligand to an NHDC have yet to be report Thus we report herein the rearrangement of an NHC ligand to yield a CCC-NHCNHDC pincer bis(imido) Ta complex and the reactivity of CCC-NHC pincer bis(imido) Ta complex with adventitious proton sources to form a new (BuCiCiCBu)Ta(V)(tert-butylamido)(tert-butylimido)iodo complex Results and Discussion

While investigating the synthesis of the recently reported CCC-NHC Ta bis(imido) complex[3a] complex 1 was treated with excess lithium tert-butylamide in toluene at temperatures ranging from room temperature up to 80 degC (Scheme 1) In an effort to isolate solely the CCC-NHC Ta bis(imido) from the extraneous products the crude material was washed with various hydrocarbon solvents (hexanes and pentane) Over time an extended period of time (2 month) crystals of a CCC-NHCNHDC complex grew from the pentane washes Despite numerous attempts to reproduce the exact experiment a concise synthesis of NHDC complex 3 has yet to be found

Scheme 1 Synthesis of (1-(3-butylimidazol-1-yl-2-lithium-4-idene 3-(3-butylimidazol-1-yl-2-idene)-2-phenylene) bis(tert-butylimido)tantalum(V) 3

N NTaBu Bu

t-BuNHLi

TaBu Nt-But-BuN

N NBu Bu

supernatant

months

excess

Molecular Structure Determination X-ray quality crystals of complex 3 grew from a saturated pentane solution 3 at room

temperature An ORTEPreg plot of the molecular structure of complex 3 is presented in Figure 1-3 along with selected metric data X-ray crystallographic data confirmed the tridentatebonding of the CCC-NHC and CCC-NHCNHDC pincer ligand to the Ta(V) center incomplexes 3 Complex 3 has distorted trigonal bipyramidal coordination due to theconstraints of the pincer ligand The NHC and NHDC ligands occupied coordination sitestrans to each other and had a CNHC-Ta-CNHDC bond angle of 13910(13)deg The Ta-CNHDC bondlength was 2277(4) Aring This unprecedented bond was comparable (-001 Aring) to the other Ta-

Vol 1 Pag121

CNHC bond length incorporated into a pincer ligand At 2286(4) Aring the Ta-CNHC was in agreement (plusmn013 Aring) with other known Ta-CNHC bond lengths[3] The Ta-Caryl bond length was 2282(5) Aring which was within 012 Aring of other Ta pincer complexes with a similar aryl group flanked by neutral donors[13] With a bond lengths of 1866(4) Aring and 1825(4) the Ta-Nimido bonds were similar (plusmn0081 Aring) to other reported Ta bis(imido) complexes[14] At 11767(19)deg the Nimido-Ta-Nimido was in similar to other Ta bis(imido)[14b] The C(7)-Li(7) bond length was 2117 Aring analogous to the Li-CNHC bond length (-0058 Aring) of the free NHDC by Robinson[8]

Figure 1 Molecular structure of complex 3 (1-(3-butylimidazol-1-yl-2-lithium-4-idene 3-(3-butylimidazol-1-yl-2-idene)-2-phenylene) bis(tert-butylimido)tantalum(V) Only one formula unit shown and the hydrogens have been omitted for clarity Thermal ellipsoids are shown at 50 probability Selected bond lengths (Aring) and angles (deg) Ta(1)-C(1) 2281(4) Ta(1)-C(8) 2277(4) Ta(1)-C(14) 2286(4) Ta(1)-N(5) 1869(3) Ta(1)-N(6) 1826(3) C(8)-Ta(1)-C(14) 13910(13) C(1)-Ta(1)-C(14) 6950(14) C(8)-Ta(1)-C(1) 6969(13) N(6)-Ta(1)-N(5) 11768

Expanding the view of the crystal structure of 3 to include two formula units illustrates the multiple interactions between the Li and NHDC carbons which bridges to form a dimer (Figure 2) The most notable interaction is between the NHDC carbon and the Li which has a length of 2466 Aring The Li-CNHDC interaction length is larger than the Li-CNHDC length in Robinsonrsquos free NHDC complex[8] but smaller than the analogous K-CNHDC interaction in the Y NHCNHDC dimmers reported by Arnold[10] Furthermore a Li-Nimido was observed between the two formula units in the dimer The Li-Nimido interaction was 2032 Aring in length similar to the Li-Nimido interactions in Wigleyrsquos Ta bis(imido) complexes[14a] This interaction explains the deviation between the Ta(1)-N(6)-C(25) bond angle (1727(3)deg) and Ta(1)-N(5)-C(21) bond angle 1560(3)deg Figure 2 Dimeric view of 3 (hydrogens omitted for clarity)

Attempts to prepare the NHDC pincer In an effort to find a direct synthesis of

NHDC pincer complex 3 the previously reported bis(imido) complex (2) was heated at elevated temperatures (Scheme 2) After heating the reaction for 14 days at 120 degC signals consistent

with a new CCC-NHC pincer complex were observed These new signals increased in intensity as the heat was increased to 160 degC after 4 days and were the only signals observed after the reaction was heated at 160 degC for 13 days The most obvious of these signals was a diastertopic multiplet at δ 407 corresponding to methylene group adjacent to the nitrogen of a new CCC-NHC pincer complex as illustrated in Figure 3 A new singlet at δ 161 with an integration of 9H was consistent with the a tert-butylimido ligand Another singlet with similar intensity (9H) at δ 086 suggested one of the tert-butylimido ligands of the starting material had transformed to a tert-butylamido ligand This data and the lack of a second set of butyl signals corresponding to the inequivalent butyl groups of NHDC complex 3 suggested that complex 3 was not formed Rather the bis(imido) complex reacts with adventitious water to form CCC-NHC Ta tert-butylamido tert-buytlimido iodo complex 4

Vol 1 Pag122

Scheme 2 Attempted preparation of the NHDC pincer complex

TaBu Nt-But-BuN

N NBu Bu

N NTaBu Bu

355360365370375380385390395400405410415420425430435440445450455460465470475480485490495500f1 (ppm)

14 days 120 degC

4 days 160 degC

13 days 160 degC

Figure 3 1H NMR spectra upon heating of 2 showing slow conversion to 4 due to adventitious water In one attempt to grow crystals of bis(imido) complex 2 both tablet and needle

crystals were observed Apparently a source of adventitious protons was available as upon solving the X-ray crystal data for the tablets the molecule was identified as imidoamido complex 4 The crystals were grown by layering a saturated THF solution with hexanes An ORTEP plot of complex 4 is presented in Figure 2 along with select metric data X-ray crystallographic analysis confirmed the tridentate binding of the ligand and the distorted octahedral geometry of complex 4 All data regarding the CCC-NHC pincer ligand (ie Ta-NHC bond lengths Ta-aryl bond length CNHC-Ta-CNHC bond angle and CNHC-Ta-CNHC) were almost identical to the previously reported CCC-NHC Ta pincer complexes[3a 3c] The imido ligand of complex 4 has a bond length of 1786(5) Aring which is longer than another reported Ta complexes containing a linear tert-butylimido ligand trans to a halogen It is similar to other Ta imido complexes bearing a CCC- NHC pincer ligand[3a 15] The tert-butylamido ligand of complex 4 was comparable to other similar Ta tert-butylamido bond distances[16] At 30769(4) Aring the Ta-I bond length is one of the longest Ta-I bond lengths

reported[3c 16b 17]

Figure 5 Molecular structure of (13-bis(3-butylimidazol-1-yl-2-idene)-2-phenylene)(tert-butylamido)(tert-butylimido)iodo tantalum(V) (4) Thermal ellipsoids are shown at 50 probability Selected bond lengths (Aring) and angles (deg) Ta(1)-C(7) 2291(4) Ta(1)-C(14) 2285(4) Ta(1)-C(1) 2251(4) Ta(1)-N(6) 2018(3) Ta(1)-N(5) 1786(5) Ta(1)-I(1) 30769(4) C(14)-Ta(1)-C(7) 13884(15) C(1)-Ta(1)-C(7) 6951(14) C(1)- Ta(1)-C(14) 6935(16)

Proposed Mechanism A plausible mechanism for the synthesis of the NHDC complex 2 is illustrated in Scheme 3

It was hypothesized that a backbone carbon of one of the C-2 NHC ligand in complex 2 is deprotonated by the excess lithium tert-butylamide to form intermediate NHDC complex a The amine protonates C-2 of intermediate NHDC complex a which produces a free MIC arm

Vol 1 Pag123

in b The free MIC rotates about the CAryl-NMIC bond to produce intermediate c A bond is formed between C-5 of the free MIC intermediate and Ta producing d Ta NHCMIC intermediate d can be deprotonated at C-2 of the MIC ligand yielding NHCNHDC pincer complex 3

Scheme 3 A reasonable initial hypothesis for the mechanism of the formation of 3

LiNR2N N

N NTaBu BuNt-But-BuN

N NTaBu Bu

Nt-But-BuN

N TaBu

Nt-But-BuN

TaBu Nt-But-BuN

- HNR2

TaBu Nt-But-BuN

- R2N-

Computational Results The geometry minimized energy (DFT-PBEmod-LANL2DZ 6-31G(d)) for the proposed intermediate a was found to be 128 kcal mol-1 higher in energy than the value computed for the monomer of 3 A direct transition state was located and found to have an unreasonably high energy (60 kcal mol-1) Therefore it seems unlikely that the interconversion occurs in a single-step direct pathway lending plausibility to the proposed multi-step path in Scheme 3

These three structures and their relative energies are illustrated in Figure 6 Conclusion

In conclusion novel bis(imido) Ta complexes bearing a CCC-NHC and CCC-NHCNHDC pincer ligand were synthesized Treatment of complex 2 with lithium tert-butylamide at elevated temperatures yielded CCC-NHCNHDC pincer complex 3 Complex 3 is not only a rare example an X-ray crystallographically determined Ta NHC but is also the first example of an X-ray crystallographically determined Ta NHDC complex and NHDC pincer complex Exposure of bis(imido) complex 3 to adventitious proton sources yielded (BuCiCiCBu)Ta(V)(tert-butylamido)(tert-butylimido)iodo complex (4) References [1][a]A J Arduengo R L Harlow M Kline J Am Chem Soc 1991 113 361 [b]A Igau H Grutzmacher A Baceiredo G Bertrand J Am Chem Soc 1988 110 6463 [c]D Bourissou O Guerret F P Gabbai G Bertrand Chem Rev 2000 100 39 [2]W A Herrmann Angew Chem Int Ed 2002 41 1290

Figure 6 Computed relative energies of a TS and the monomer of 3

a 128 kcal mol-1 TS-a-3-monomer 60 kcal mol-1

3-monomer 0 kcal mol-1

Vol 1 Pag124

[3][a]T R Helgert X Zhang H K Box J A Denny H U Valle A G Oliver et al Organometallics 2016 [b]L P Spencer C Beddie M B Hall M D Fryzuk J Am Chem Soc 2006 128 12531 [c]T R Helgert T K Hollis A G Oliver H U Valle Y Wu C E Webster Organometallics 2014 33 952 [4]R H Crabtree Coord Chem Rev 2013 257 755 [5]S Gruumldemann A Kovacevic M Albrecht J W Faller R H Crabtree Chem Commun 2001 2274 [6]E Aldeco-Perez A J Rosenthal B Donnadieu P Parameswaran G Frenking G Bertrand Science 2009 326 556 [7]M Heckenroth A Neels M G Garnier P Aebi A W Ehlers M Albrecht ChemmdashEur J 2009 15 9375 [8]Y Wang Y Xie M Y Abraham P Wei H F Schaefer P V R Schleyer et al J Am Chem Soc 2010 132 14370 [9][a]M J Bitzer A Pothig C Jandl F E Kuhn W Baratta Dalton Trans 2015 44 11686 [b]Y Wang Y Xie P Wei H F Schaefer G H Robinson Dalton Trans 2016 45 5941 [c]M J Bitzer F E Kuumlhn W Baratta J Catal 2016 338 222 [d]Y Wang Y Xie M Y Abraham P Wei H F Schaefer P V R Schleyer et al Organometallics 2011 30 1303 [e]Y Wang M Y Abraham R J Gilliard P Wei J C Smith G H Robinson Organometallics 2012 31 791 [f]R A Musgrave R S P Turbervill M Irwin J M Goicoechea Angew Chem Int Ed 2012 51 10832 [g]R A Musgrave R S P Turbervill M Irwin R Herchel J M Goicoechea Dalton Transactions 2014 43 4335 [h]J B Waters R S P Turbervill J M Goicoechea Organometallics 2013 32 5190 [i]M Vogt C Wu A G Oliver C J Meyer W F Schneider B L Ashfeld Chem Commun 2013 49 11527 [j]D A Valyaev M A Uvarova A A Grineva V Cesar S N Nefedov N Lugan Dalton Trans 2016 45 11953 [k]C Pranckevicius D W Stephan Chem - Eur J 2014 20 6597 [10]P L Arnold S T Liddle Organometallics 2006 25 1485 [11][a]M Vogt O Rivada-Wheelaghan M A Iron G Leitus Y Diskin-Posner L J W Shimon et al Organometallics 2013 32 300 [b]E Poverenov D Milstein in Organometallic Pincer Chemistry Eds G van Koten D Milstein 2013 pp 21-47 (Springer Berlin Heidelberg Berlin Heidelberg) [12][a]A D Ibrahim K Tokmic M R Brennan D Kim E M Matson M J Nilges et al Dalton Trans 2016 45 9805 [b]G E Martinez C Ocampo Y J Park A R Fout J Am Chem Soc 2016 138 4290 [c]A D Ibrahim S W Entsminger L Zhu A R Fout ACS Catal 2016 6 3589 [d]W D Clark K N Leigh C E Webster T K Hollis Aust J Chem 2016 69 573 [e]H U Valle G Akurathi J Cho W D Clark A Chakraborty T K Hollis Aust J Chem 2016 69 565 [f]S W Reilly G Akurathi H K Box H U Valle T K Hollis C E Webster J Organomet Chem 2016 802 32 [g]S W Reilly C E Webster T K Hollis H U Valle Dalton Trans 2016 45 2823 [h]E B Bauer G T S Andavan T K Hollis R J Rubio J Cho G R Kuchenbeiser et al Organic Letters 2008 10 1175 [i]J Cho T K Hollis T R Helgert E J Valente Chem Commun 2008 5001 [j]J Cho T K Hollis E J Valente J M Trate Journal of Organometallic Chemistry 2011 696 373 [k]W D Clark J Cho H U Valle T K Hollis E J Valente J Organomet Chem 2014 751 534 [l]T R Helgert T K Hollis E J Valente Organometallics 2012 31 3002 [m]X Zhang A M Wright N J DeYonker T K Hollis N I Hammer C E Webster et al Organometallics 2012 31 1664 [n]M Raynal C S J Cazin C Vallee H Olivier-Bourbigou P Braunstein Chem Commun 2008 0 3983 [o]M Raynal R Pattacini C S J Cazin C Valleacutee H l n Olivier-Bourbigou P Braunstein Organometallics 2009 28 4028 [p]W Zuo P Braunstein Organometallics 2012 31 2606 [q]W Zuo P Braunstein Dalton Transactions 2012 41 636 [r]A R Chianese M J Drance K H Jensen S P McCollom N Yusufova S E Shaner et al Organometallics 2014 33 457 [s]A R Chianese A Mo N L Lampland R L Swartz P T Bremer Organometallics 2010 29 3019 [t]A R Chianese S E Shaner J A Tendler D M Pudalov D Y Shopov D Kim et al Organometallics 2012 31 7359 [u]S M M Knapp S E Shaner D Kim D Y Shopov J A Tendler D M Pudalov et al Organometallics 2014 33 473 [v]Y-M Zhang J-Y Shao C-J Yao Y-W Zhong Dalton Trans 2012 41 9280 [w]E Peris R H Crabtree Coord Chem Rev 2004 248 2239 [x]R E Andrew L Gonzalez-Sebastian A B Chaplin Dalton Trans 2016 45 1299 [y]E Peris R H Crabtree in The Chemistry of Pincer Compounds (Ed C M Jensen 2007 pp 107-124 (Elsevier Science BV Amsterdam) [z]E M Matson G Espinosa Martinez A D Ibrahim B J Jackson J A Bertke A R Fout Organometallics 2015 34 399

Vol 1 Pag125

[13][a]H C L Abbenhuis N Faiken D M Grove J T B H Jastrzebski H Kooijman P Van Der Sluis et al J Am Chem Soc 1992 114 9773 [b]H C L Abbenhuis N Feiken H F Haarman D M Grove E Horn H Kooijman et al Angew Chem Int Ed 1991 30 996 [14][a]T C Baldwin S R Huber M A Bruck D E Wigley Inorg Chem 1993 32 5682 [b]Y W Chao P A Wexler D E Wigley Inorg Chem 1990 29 4592 [15]A Merkoulov S Schmidt K Harms J Sundermeyer Z Anorg Allg Chem 2005 631 1810[16][a]R E Blake D M Antonelli L M Henling W P Schaefer K I Hardcastle J E Bercaw Organometallics1998 17 718 [b]B L Yonke A J Keane P Y Zavalij L R Sita Organometallics 2012 31 345[17][a]P Bernieri F Calderazzo U Englert G Pampaloni J Organomet Chem 1998 562 61 [b]F G N ClokeP B Hitchcock M C Kuchta N A Morley-Smith Polyhedron 2004 23 2625 [c]M J McGeary A S Gamble JL Templeton Organometallics 1988 7 271 [d]F Calderazzo G Pampaloni G Pelizzi F Vitali Organometallics1988 7 1083 [e]R P Hughes S M Maddock A L Rheingold I A Guzei Polyhedron 1998 17 1037 [f]T WHayton P J Daff P Legzdins S J Rettig B O Patrick Inorg Chem 2002 41 4114 [g]T W Hayton PLegzdins B O Patrick Inorg Chem 2002 41 5388 [h]M V Barybin W W Brennessel B E Kucera M EMinyaev V J Sussman V G Young et al J Am Chem Soc 2007 129 1141

Acknowledgements The National Science Foundation (OIA-1539035) is gratefully acknowledged for financial support

Vol 1 Pag126

Hydrogen bonds in Novel Pd(II) Coordination complexes containing fluorinated Schiff Bases A Structural Study

J Roberto PioquintominusMendoza1 Marcos Flores-Aacutelamo2 Rubeacuten A Toscano3

and David Morales-Morales3

1Facultad de Quiacutemica Universidad Autoacutenoma de Yucataacuten Calle 43 No 613 x C 90 Col Inalaacutembrica CP 97069 Meacuterida Yucataacuten Meacutexico E-mail r_pioquinto_12hotmailcom

2Facultad de Quiacutemica (UNAM) Ed B Ave Universidad 3000 Coyoacaacuten CDMX Meacutexico 3Instituto de Quiacutemica Universidad Nacional Autoacutenoma de Meacutexico Circuito Exterior sn Ciudad Universitaria CP

04510 CDMX Meacutexico E-mail damorunammx

Abstract A series of novel fluorinated Schiff bases and their Pd(II) derivatives were synthesized and fully characterized by different analytical techiniques including infrarred elemental analysis nuclear magnetic resonance and when possible by sigle crystal X-ray diffraction analysis Due to the presence of ndashOH groups in the structures of the series of compounds they exhibit intra- andor intermolecular hydrogen bonds which are important for the stability of the lattice in the solid state and relevant for their study in crystal engineering In addition to this important non-covalent interactions compounds L3 and L4 also exhibited π-π stacking interactions of the phenolic and benzene rings

Keywords Fluorinated Schiff Bases Palladium (II) complexes hydrogen bond interactions supramolecular chemistry crystal engineering coordination chemistry

Background Schiff bases are compounds that include on their structures the azomethine group These species are known since the 19th century and have been widely studied due to their potential applications in many areas of chemistry this being particularly true for homogeneous catalysis mainly for their use as catalysts in Suzuki-Miyaura Couplings[1] as well as for their biological activity studies as antifungal[2] antimicrobial[34] antiviral and anticancer[5] Thus in this work we report a series of novel Schiff bases and their Pd(II) derivatives as well as their study in solid state to determine how ldquoweakrdquo interactions such as hydrogen bonds determine their molecular arrangements in the solid state

Experimental section The Schiff Bases were synthesized by a traditional method ie the condensation reaction between 24-dihydroxybenzaldehyde and fluorinated anilines in an equimolar ratio using Na2SO4 as desiccant agent and a mixture of solvents methanoltoluene as reaction media having a reaction time of 48 hours after which the solvent was removed under reduced pressure affording a series of yellow microcrystalline powders which then were further purified by recrystallization from a CH2Cl2hexane solvent system (yields 90-97) Scheme 1

Vol 1 Pag127

+ PhNH2 Methanol Toluene

RefluxNa2SO4

48 h OHaHbO

F3C CF3

Scheme 1 Synthesis of fluorinated Schiff bases

Synthesis of Pd(II) Schiff base coordination complexes Coordination complexes were synthesized from the reactions between the synthesized fluorinated Schiff bases L1-L4 and [Pd(CH3COO)2] in a 21 molar ratio in a solvent mixture of MeCNacetone (11) as reaction media during 24 hours After this time the solvent was removed under reduced pressure affording a series of yellow powders which were then washed with n-hexane to produce microcrystalline yellow powders of complexes PdL1 PdL2 PdL3 and PdL4 in yields that go from 90 to 95 (Scheme 2)

OHaHbO

F3C CF3

PdL1 PdL2

PdL3 PdL4

i) (CH3)2COii) Pd(CH3CO2)2 CH3CN

Scheme 2 Synthesis of the Schiff base Pd(II) coordination complexes

Results and discussion Infrared Spectroscopy Fluorinated Schiff bases L1-L4 were characterized by infrared spectroscopy In these spectra the bands due to the presence of the -OH functional groups were observed in the range of ν = 3238 to 3242 cmminus1 while the signals due to the presence of C=Nimine bonds were observed from ν = 1622 to 1630 cmminus1 As expected the very same signals on the coordination complexes PdL1-PdL4 reveal a shift to lower frequencies from those of the free ligands Thus bands due to the -OH groups span from ν = 3153 to 3210 cmminus1 while those bands corresponding to the C=Nimine are now observed between ν = 1589 and 1621 cmminus1 This effect can be attributed to the metal coordination

Vol 1 Pag128

Nuclear Magnetic Resonance (NMR) In general the 1H NMR spectra of the series of compounds show two signals for the -OH groups One located from δ = 1336 to 1297 ppm assigned to the -OHa group and the second one observed between δ = 935 to 899 ppm which were assigned to the -OHb group Signals attributable to the iminic group were observed about δ = 898 to 873 ppm for the free ligands while a significant up field shift in the 1H NMR spectra is observed for the imine proton upon coordination to the Pd(II) center of about 10 ppm This effect could be due to the shielding effect On the other hand in the 13C1H NMR spectra of the Pd(II) coordination complexes the iminic carbon is more shielded than in the free ligand (about 2 ppm) this effect could be attributed to the formation of the six membered ring chelates

X-ray DiffractionCrystals suitable for single crystal X-ray diffraction analysis of the Schiff bases L1 L3 and L4and their Pd(II) derivatives PdL1 PdL3 and PdL4 were obtained from solutions of acetoneand DMSO respectively These analyses showed that for all the cases the lattices arestabilized by intermolecular hydrogen bonds produced between the -OH and imine groupsfor free ligands and between the -OH and crystallization solvent molecules for thecoordination complexes All Pd(II) complexes crystalized in the P 21c space groupexhibiting slightly distorted square planar geometries Selected bond lengths and bond forthe Pd(II) complexes PdL1 PdL3 and PdL4 are shown in Table 1

Table 1 Selected bond lengths [Aring] and angles [deg] for PdL1 PdL3 and PdL4 Bond lengths in Aring

PdL1 PdL3 PdL4 PdndashN 20149 (19) 20157 (15) 20234 (18) PdndashO 19698 (16) 19689 (13) 19825 (14)

Bond Angles in ordm OndashPdndashN 9164 (7) 9192 (6) 9202 (6) NndashPdndashN 1800 1800 18000 (8) OndashPdndashO 1800 18000 (4) 18000 (6)

Bond lengths for PdndashN ranged from 20149 to 20234 Aring while those for PdndashO are between 19689 to 19825 Aring with bite angles closer to 90ordm These values of bond lengths and angles are similar to other isostructural complexes previously described in the literature [1] As a representative example Figures 1 and 2 shown the molecular structures for L4 and its Pd(II) derivative PdL4 respectively

Vol 1 Pag129

Figure 1 Molecular structure for L4 Figure 2 Molecular structure for PdL4

A quick view to the latter structure (PdL4) reveals the presence of two water molecules in the lattice Thus this complex forms a hydrogen bond network involving the O coordinated to Pd(II) the free OH group of the Schiff base ligand and the two water molecules (Figure 3 presents the graph set descriptor and Table 2 presents the corresponding bond lengths and angles) Parameters described in Table 2 are in good agreement with strong hydrogen bonds

Figure 3 Hydrogen bond network in PdL4

Table 2 Hydrogen bonds in the crystal structure of PdL4 D-HA d(D-H) d(HA) d(DA) lt(D-HA)

O(2)-H(2D)O(1W)1 0837(17) 1761(18) 2596(2) 176(3) O(1W)-H(1E)O(2)2 0839(17) 200(2) 2809(2) 161(3) O(1W)-H(1D)O(1)3 0852(17) 1920(18) 2768(2) 174(3)

Symmetry transformations used to generate equivalent atoms 1 -x+2y-12-z+12 2 -x+2-y-z+1 3 -x+2y+12-z+32

Vol 1 Pag130

Conclusions A series of fluorinated Schiff bases and their corresponding Pd(II) coordination complexes were synthesized and unequivocally characterized Analysis by single crystal X-ray diffraction experiments shown these compounds to exhibit intra- and intermolecular hydrogen bonds in the solid state interactions that greatly benefit the structure of the lattice These interactions where studied and a crystal engineering analysis produced which could be relevant for the development of new materials with potential applications in catalysis and other areas of chemistry In all cases studied the coordination complexes exhibited the Pd(II) center located into a slightly distorted squared planar geometry

Acknowledgements We would like to thank Chem Eng Luis Velasco Ibarra Dr Francisco Javier Peacuterez Flores Q Ereacutendira Garciacutea Riacuteos MSc Lucia del Carmen Maacuterquez Alonso MSc Lucero Riacuteos RuizMSc Alejandra Nuacutentildeez Pineda (CCIQS) Q Mariacutea de la Paz Orta Peacuterez and Q RociacuteoPatintildeo-Maya for technical assistance The financial support of this research by CONACYT(grant No CB2010ndash154732) and PAPIIT (grants No IN201711ndash3 and IN213214ndash3) isgratefully acknowledged

References

1 Kilic A Kilinc D Tas E Yilmaz I Durgun M Ozdemir I Yasar S J Organomet Chem 2010 695 697ndash706 2 Shalini S Girija CR Sathish C D Venkatesha T V Chem Sci J 2016 7 122-126 3 Satheesh CE Raghavendra Kumar P Sharma P Lingaraju K Palakshamurthy BS Raja Naika H Inorg Chim Acta 2016 442 1ndash9 4 da Silva C M da Silva D L Modolo L V Alves R B de Resende M A Martins C V B de Faacutetima A J Adv Res 2011 2 1ndash8 5 Petrovic V P Zivanovic M N Simijonovic D Dorovic J Petrovic Z D Markovic S D RSC Adv 2015 5 86274ndash86281

Vol 1 Pag131

Polymeric supports for heterogenization of zirconocene aluminohydrides

Zertuche-Martiacutenez Sergio A 1 Peralta Rodriacuteguez Reneacute D 1 Peacuterez Camacho Odilia1

1Centro de Investigacioacuten en Quiacutemica Aplicada Blvd Enrique Reyna Hermosillo 140 Col San Joseacute de los Cerritos Saltillo CP 25294 Coahuila Meacutexico

Abstract Functionalized polymer particles prepared with commercial polymerizable surfactants (anionic Hitenol BC and non-ionic Noigen RN) by miniemulsion polymerization have been used as carriers of catalytic species in the polymerization and copolymerization of olefins and alpha olefins producing homogeneous copolymers In this work particles of crosslinked poly (styrene - acrylic acid - divinylbencene) P(S-AA-DVB) were prepared by miniemulsion polymerization and used as organic supports for metallocene derivatives for the polymerization and copolymerization of ethylene and 1-hexene in slurry The particles in the polymer latex were characterized by dynamic light scattering (DLS) to determine the average particles diameter and Z potential The crosslinked polymers were characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) The dried polymer particles were used to support zirconocene aluminohydrides catalysts The supported catalysts (nBuCp)2ZrH3AlH2 MAO P(S-DVB-AA) containing neutral or ionic groups from the polymeric surfactants and the AA were tested and compared as catalytic systems in the homopolymerization of ethylene and copolymerization of ethylene and 1-hexene The polyolefins obtained with the new catalytic systems were characterized by 13C nuclear magnetic resonance spectroscopy (NMR) DSC gel permeation chromatography (GPC) and SEM The catalytic activity of each supported system was also determined

Introduction In recent decades there has been considerable progress in the polymerization of olefins In order to improve the morphology of polyethylene and polyethylene-alfa-olefin copolymers and to have an alternative to silica supports traditionally used to immobilize metallocenes organic supports based on polymers have been studied Polystyrene based supports crosslinked with divinyl benzene and functionalized with acrylic acid and polymeric surfactants containing a number of ethylene oxide units in their hydrophilic chain were used The supported metallocene interacts directly or indirectly with these groups by electrostatic interactions where it ionizes and forms active species [1]

Experimental section The terpolymers P(S-DVB-AA) were synthesized from styrene divinylbenzene and acrylic acid with a molar ratio of (9253) using polymerizable surfactant Hitenol BC with different chain length of ethylene oxide (10 30) and molar ratio of (9451) and non-ionic Noigen RN30 by miniemulsion polymerization A pre-emulsion was formed by mixing in a flat bottom flask an aqueous phase (formed by water and surfactant) and an oil phase (monomers hexadecane initiator) under agitation (1000 rpm) The resulting pre-emulsion was subjected to the action of ultrasound (Sonics 500 W 81 power) under cooling to avoid undesirable polymerization for 3 min and the flask and contents were transferred to a heating bath Then the polymerization was carried out at 72 degC with magnetic stirring (400 rpm) for 16 hours [2] Lattices obtained were analyzed by dynamic light scattering (DLS) Finally lattices were purified by dialysis and lyophilized The dry polymer was characterized by scanning electron microscopy (SEM) and Differential Scanning Calorimetry (DSC) The particles of dried latex were immersed in toluene and the suspension was sonicated for 30 min in an ultrasonic bath (40 W) Then 20 ml of 15 wt MAO solution in toluene at 0 degC were added and the mixture was stirred for 12 hours at room temperature Subsequently

Vol 1 Pag132

the solid was washed five times with 20 ml of toluene removing excess MAO and the particles were dried for 6 h under vacuum Particles modified with MAO P(S-DVB-AA MAO) were re-suspended in 20 ml of toluene the solution was cooled to 0 degC and aluminohydride (n-BuCp)2ZrH3AlH2 (248 X 10-3 mol) solution in toluene was added The mixture was stirred at room temperature for 12 h and then the particles were washed five times with 20 ml of toluene and dried at room temperature for 6 h under high vacuum The supported catalyst was tested in the slurry polymerization and copolymerization of ethylene and 1-hexene at 70 degC and 289 kPa (42 psi) of ethylene pressure Iso-octane was used as the solvent with different ratios of MAO [3] Polymers and copolymers obtained were characterized by Gel Permeation Chromatography (GPC) Nuclear Magnetic Resonance (NMR) 13C DSC and SEM

Results The P(S-AA-DVB) lattices obtained by the method of miniemulsion polymerization showed high monomers conversions and stability with average particles diameter of 619 plusmn 2 nm and 545 plusmn 3 nm for Hitenol BC10 and 30 respectively and average diameters of 151 plusmn 8 nm for Noigen RN30 (Table 1) Differences in particle sizes were attributed to the ionic character of the Hitenol BC surfactants where its sulfonate termination can interact with chains of ethylene oxide and the hydrophobic part of the molecule with the nonyl chain of the additional surfactant generating smaller particles [4] The Z potential values of miniemulsions prepared with different polymerizable surfactants are shown in Table 1 in which we see that for Hitenol BC 10 and 30 the values obtained were ~ -50mV (millivolts) while for the surfactant Noigen RN30 ~ -20 mV The lattices prepared withionic surfactants showed good stability due to its negative charge whereas the onesprepared with the nonionic surfactant showed higher values of Z potential so thatcoagulation of the polymer particles can occur [5]The results of the glass transition temperatures (Tg) obtained for each of the particles areshown in Table 1 where it can be seen that the Hitenol BC series and Noigen RN30 have aTg adequate to carry out the polymerization of ethylene in slurry at 70 degC

Table 1 Characteristics of the particles obtained with the different surfactants by miniemulsion polymerization

Surfactant AA ()

Conversion ()

Z Potential (mV)

DP DLS (nm)

DP SEM (nm) Tg (degC)

Hitenol BC30 3 9132 (-) 479 plusmn 2 619 plusmn 2 5906 plusmn 2 11305 plusmn 3 Hitenol BC10 3 9154 (-) 534 plusmn 3 545 plusmn 3 5402 plusmn 1 11357 plusmn 3 Noigen RN30 1 9235 (-) 207 plusmn 2 1509 plusmn 8 8426 plusmn 11 8946 plusmn 1

The polymer particles obtained after purifying and drying the lattices were dispersed in toluene modified with MAO and subsequently with the zirconocene aluminohydride [6] (figure 1) to be used as catalysts for the polymerization and copolymerization of ethylene and 1-hexene in slurry

P(S-DVB-AA)

Figure 1 Schematic representation of the supported zirconocene aluminohydride

Vol 1 Pag133

Figure 2a shows the SEM micrograph of the particles obtained using the polimerizable surfactant Hitenol BC30 where the spherical morphology of the particles can be compared with the average particle size obtained by DLS (Table 1) Polymer particles obtained with Hitenol BC series do not have significant difference between the two measurement techniques (gt 3nm) However in the case of the particles obtained with the surfactant Noigen RN a big change in Dp (lt60 nm) can be seen This is attributed to less strong steric interactions between particles with nonionic surfactant leading to the formation of small domains in the particle containing AA and to the separation in droplets to stabilize in a more favorable manner [2] Figure 2b shows the SEM micrographs of polyethylene obtained with heterogeneous catalysts in organic supports which shows reproducibility of the nearly spherical morphology (agglomerates) from polymeric supports with an increase in size of ~ 200 times

Figure 2 SEM of a) Particles of P(S-DVB-AA) obtained with Hitenol BC30 b) HDPE obtained with the catalytic system supported on this P(S-DVB-AA) particles

The new catalytic systems showed activities from 1300 to 2600 kg PE(mol Zr h) The molecular weights of the homopolymers (HDPE) obtained (R- 1 3 5 in Table 2) were higher than 74000 gmol additionally molar mass dispersities (Đ) were lower than 21 while for PE-HEX (R- 2 4 and 6 in table 2) where 1-hexene was used as comonomer the activities decreased from 13 to 20 compared to homopolymerizations due to the longer chain size of 1-hexene its incorporation could slow down the rate of incorporation of ethylene monomer however molecular weights remained between 82000 gmol to 66000 gmol with Đ from 318 to 185 As far as the melting temperatures and percent crystallinity of the polymers as expected the copolymers (PE-HEX) exhibited lower melting temperatures (Tm = 126 degC) and lower crystallinity compared with HDPE (Tm = 133 degC) due to the presence of short chain branches (four carbons) in the polyethylene backbone

Table 2 Polymerization results and polyethylenes characterization

R Surfactant Activity (kg PE

(mol Zr h) Comonomer Tm

(degC) Cristalinity

() Đ Mw (gmol)

1 Hitenol BC30 266941 - 13328 7082 182 74800 2 Hitenol BC30 130419 1-HEXENE 12642 4782 318 82600 3 Hitenol BC10 240792 - 13305 6855 16 94700 4 Hitenol BC10 210271 1-HEXENE 12629 6931 259 66700 5 Noigen RN30 204540 - 13283 6872 208 107800 6 Noigen RN30 164172 1-HEXENE 12555 5785 185 75500

R Reaction identification

Figure 3 shows the 13C NMR spectrum of the polymer obtained in experiment R-2 where peaks correspond to tertiary carbons observed at 35 ppm and the carbons of the branches (1-4) from the incorporation of 1-hexene in the polymer chain According to the results

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obtained by NMR the comonomer incorporation was calculated as low as 008 to 043 mol but significantly enough to modify the properties of the polymer [7]

Figure 3 13C NMR spectrum in tetra-chloroethane Tol-d8 of the copolymer obtained in R2 Table 2

Conclusions The aluminohydride zirconocenes heterogenized on polymeric supports showed high catalytic activities in the synthesis of HDPE and LLDPE (PE-HEX) with values between 1300 and 2660 kg PE(mol Zr h) with high molecular weights and narrow dispersities (Đ~ 23) characteristic of PE prepared with metallocene systems

References [1] Bianchini D Stedile F C amp Dos Santos J H Z Appl Catal A Gen (2004) 261 57ndash67[2] Musyanovych A Rossmanith R Tontsch C amp Landfester K Langmuir (2007) 23 5367ndash5376[3] Villasana Salvador C I (Centro de Investigacioacuten en Quiacutemica Aplicada 2013)[4] Atta A M Dyab A K F amp Al-Lohedan H A J Surfactants Deterg (2013) 16 343ndash355[5] Conde Kosegarten C E amp Munguiacutea Jimeacutenez M T Temas Sel Ing Aliment (2012) 2 1ndash18[6] Li K Dai C amp Kuo C Catal Commun (2007) 8 1209ndash1213[7] Rojas de Gaacutescue B et al Polymer (Guildf) (2002) 43 2151ndash2159

Acknowledgements The authors would like to thank the financial support of CONACYT for 167901 and 168472 projects and the fellowship of Sergio Zertuche for graduate studies (M Sc) at CIQA and also thank Maricela Garciacutea Viacutector Comparaacuten and Gladis Cortez for technical support

Vol 1 Pag135

Rotaxanes Fulvalenes and Catenanes Optimization of Photosynthesis by Nanocomposites

Luis Alberto Lightbourn Rojas1 Luis Amarillas Bueno1 Rubeacuten Leoacuten Chan3

1Instituto de Investigacioacuten Lightbourn AC E-mail lalrbioteksacom

Global warming is predicted to have a negative impact on plant growth due to the damaging effect of high temperatures on plant development Solar radiation (electromagnetic radiation) is one of the most important factors that influences the growth and development of plants and is involved in many important processes such as photosynthesis phototropism photomorphogenesis opening stomata temperature of plant and soil [1]

The most heat-sensitive component of the photosynthetic apparatus some studies suggest that the high temperature increases the membrane fluidity in chloroplast thylakoids limiting carbon assimilation the ATP generation and causing damage to photosystems particularly the D1 protein of the photosynthetic machinery that is damaged due to generation of reactive oxygen species [2] The UV radiation can inhibit photosynthesis by altering gene expression and by damaging the parts of the photosynthetic machinery [3]

The high energy of UV radiation is particularly damaging to the light collector complex II (LHCII) the PSII reaction center and PSI acceptor However most of the studies have demonstrated that PSII is more sensitive to UV radiation in comparison to PSI this is due to the chemical changes which produces the UV radiation on amino acids with double bonds of the PSII proteins [4]

Plants alter their metabolism in various ways in response to elevated temperatures and exposure to UV radiation The ability of plants of responding to strong irradiation by the synthesis and accumulation of the compounds selectively absorbing in the UV in most cases is overcome by intense solar radiation Therefore the exogenous application of photoprotective compounds could be providing a reliable long-term protection against photodamage [5]

Efficient use of solar energy for photosynthesis is important for plant growth and survival especially in low and high light environments Nanotechnology and nanoscience are attracting and promising disciplines of applied science that integrate a broad range of topics related to optimize light absorption for photosynthesis while avoiding damage (Perrine) In regard mechanically interlocked structures such as fulvalene rotaxane and catenane provide a novel backbone for constructing functional materials with unique structural characteristics Therefore we have developed a new plant nutrition technology based on fulvalene rotaxane and catenane compounds [6]

The fulvalene rotaxane and catenane are molecules whose structure changes when exposed to sunlight and can remain stable in that form indefinitely It increases the uptake

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storage and availability of monochromatic ray at 563 nm Foliar application of these compounds can prevent the growth inhibition and thylakoid membrane photodamage caused by solar radiation

Then when a stimulus mdash a catalyst a small temperature change a flash of light mdash it can quickly snap back to its other form releasing its stored energy in a burst of heat These molecules are foliar applied to allow for maximum absorption and optimizers photosynthesis by helping to capture light energy efficiently and reduce photodamage

The fulvalene rotaxane and catenane applied by foliar absorption and involves an innovation in signaling and synchronization cell because provide continuity in photosynthetic energy uptake and transfer due to that clusters absorb and store energy Furthermore owing of these clusters not interrupt the metabolism on account of darkness there are no delays in the formation and maintenance of plant tissue which means the total dejection of metabolic delays and consequences translated into structural failures metabolic energetic and homeostatic that directly affect the quantity and quality of biomass [7]

References [1] Bita CE Gerats T 2013 Plant tolerance to high temperature in a changing environment

Scientific fundamentals and production of heat stress-tolerant crops Frontiers in PlantScience 4 1-18

[2] Allakhverdiev S Kreslavski V Klimov V Los D Carpentier R Mohanty P 2008 Heat stressAn overview of molecular responses in photosynthesis Photosynthesis research 98541ndash50

[3] Smith KW Gao W Steltzer H 2009 Current and future impacts of ultraviolet radiation on theterrestrial carbon balance Front Earth Sci China 334ndash41

[4] Kristoffersen AS Hamre B Frette Oslash Erga SR 2016 Chlorophyll a fluorescence lifetimereveals reversible UV-induced photosynthetic activity in the green algae TetraselmisEuropean Biophysics Journal 45 259ndash268

[5] Ramakrishna A Ravishankar GA 2011 Influence of abiotic stress signals on secondarymetabolites in plants Plant Signaling and Behavior 6 1720-1731

[6] Perrine Z Negi S Sayre RT 2012 Optimization of photosynthetic light energy utilization bymicroalgae Algal Research 1134ndash142

[7] Lightbourn R L A 2011 Descripcioacuten de la Innovacioacuten del Grupo Hyper In Modelo Bioteksade Gestioacuten de Tecnologiacutea e Innovacioacuten I + D + i = 2i ISBN978-0-9833321-7-6

Acknowledgements We would like to thank all those who have been involved with the development of this work

Vol 1 Pag137

ISSN 2448-590X

POLYMAT CONTRIBUTIONS Antildeo 1 No 1 enero-diciembre 2016 es una publicacioacuten anual editada por la Universidad Nacional Autoacutenoma de Meacutexico Ciudad Universitaria Delegacioacuten Coyoacaacuten CP 04510 Meacutexico DF a traveacutes del Instituto de Investigaciones en Materiales Avenida Universidad 3000 Col Copilco Del Coyoacaacuten CP 04510 Ciudad de Meacutexico Tel (55)56224500 y (55)56224581 wwwiimunammxpolymatcontributions polymatiimunammx Editores responsables Dr Ernesto Rivera Garciacutea Dra Betsabeacute Marel Monroy Pelaacuteez Reserva de Derechos al uso Exclusivo No 04-2015-110313532900-203 otorgado por el Instituto Nacional del Derecho de Autor ISSN 2448-590X

Responsable de la uacuteltima actualizacioacuten de este nuacutemero Instituto de Investigaciones en Materiales Dr Ernesto Rivera Garciacutea Dra Betsabeacute Marel Monroy Pelaacuteez Avenida Universidad 3000 Col Copilco Del Coyoacaacuten CP 04510 Ciudad de Meacutexico fecha de la uacuteltima modificacioacuten 20 de octubre de 2016 Las opiniones expresadas por los autores no necesariamente reflejan la postura del editor de la publicacioacuten Se autoriza la produccioacuten total o parcial de los textos aquiacute publicados siempre y cuando se notifique al editor

Plenary Lecture

Plenary Lecture - Anne-Marie Caminade - Phosphorus Dendrimers Hyperbranched Macromolecules for Nanosciences13

Plenary Lecture - Lutz H Gade - Enantioselective Catalysis with 3d Transition Metal Complexes Chiral Pincers as Stereodirecting Ligands

Session 1- Functional Polymers

Casas-Gonzaacutelez MR1Rodriacuteguez-Gonzaacutelez FJ1 - Study of plasticizing effect of agave syrup of thermoplastic Starch (tps) biofilms by method of extrusion and casting

Paula Watt Toshikazu Miyoshi Coleen Pugh - Aromatic quantification using SS NMR spectroscopy for soy-based fillers

Viacutector Cruz-Delgado Edson Pentildea-Cervantes Joseacute Perales-Rangel Marcelina Saacutenchez-Adame Fabiaacuten Chaacutevez-Espinoza Joseacute Mata-Padilla Juan Martiacutenez Colunga Carlos Aacutevila-Orta - Preparation and characterization of electrically conductive polymer nanocomposites with different carbon nanoparticles

Gonzaacutelez-Lemus LB Calderoacuten-Domiacutenguez G Farrera- Rebollo RR Guumlemes-Vera N 2 Chanona-Peacuterez JJ Salgado- Cruz MP Martiacutenez-Martiacutenez V - Impact of process variables on the recovery of tarch extracted from jicama

Hernaacutendez-Espinosa N Salazar-Montoya JA y Ramos Ramiacuterez EG -Characterization of carbohydrate-protein gels using DSC and confocal microscopy

Karina Abigail Hernaacutendez-Hernaacutendez Javier Illescas Mariacutea del Carmen Diacuteaz- Nava Claudia Muro-Urista - Study of the charge into the physicochemical properties of a composite material

A Ozaeta-Galindo B Rocha Gutieacuterrez F I Torres Rojo G Zaragoza Galaacuten O Soliacutes Canto C Soto Figueroa D Y Rodriacuteguez Hernaacutendez L Manjarrez Nevaacuterez - Characterization of chitosan membranes properties as a potential material for polycyclic aromatic hydrocarbons (PAHs) removal in water

Juan G Martiacutenez-Colunga Lina Septien Mariacutea C Gonzalez-Cantuacute Juan F Zendejo-Rodriguez Marcelina Sanchez-Adame Manuel Mata Viacutector J Cruz-Delgado Carlos A Aacutevila-Orta - Artificial weathering of polyethylenemultiwall carbon nanotubes and polyethylenecopper nanoparticles composites prepared by means of ultrasound assisted melt extrusion process

Joseacute M Mata-Padilla Viacutector J Cruz-Delgado Janett A Valdez-Garza Edson Jesuacutes L Flores-Maacuterquez Gilberto F Hurtado-Loacutepez Jesuacutes G Rodriacuteguez Velaacutezquez Carlos A Aacutevila-Orta Juan G Martiacutenez-Colunga - Thermal mechanical and electrical behavior of polypropylenemultiwall carbon nanotubes polypropylenegraphene and polypropylenecarbon black composites prepared by means of ultrasound assisted melt extrusion process

D Palma Ramiacuterez M A Domiacutenguez-Crespo A M Torres-Huerta D Del13Angel-Loacutepez - Effect of LaPO4 reinforcement on structural thermal and optical properties of PMMA

D Palma Ramiacuterez A M Torres-Huerta M A Domiacutenguez-Crespo D Del13Angel-Loacutepez - Lifetime prediction and degradability on PETPLA and PETCHITOSAN blends

Ramos-Ramirez E G Sierra-Loacutepez D Pascual-Ramiacuterez JSalazar-Montoya J A - Extraction and characterization of food biopolymers from byproducts of mango (Manguifera indica L)

Janett Valdez-Garza Nuria Gonzalez-Angel Arturo Velazquez-de Jesuacutes13Concepcion Gonzalez-Cantuacute Manuel Mata-Padilla Viacutector Cruz-Delgado13Guillermo Martinez-Colunga Carlos Avila-Orta - The effect of accelerated weathering on the mechanical behaviour of reinforced polypropylene with cooper nanoparticles and carbon nanotubes

Alejandra Abigail Zuacutentildeiga-Peacuterez Mariacutea del Carmen Diacuteaz-Nava Javier13Illescas - Atrazine remotion from aqueous solutions with a Polymerclay composite

Session 2- Functional Organic Materials

G Gonzalez de la Cruz - Plasmon-phonon coupling in multilayer graphene on polar substrates

K I Moineau-Chane Ching C Chen D Le - Design and synthesis of new small molecules for electronic organics via direct hetero-arylation using ligand-less palladium catalyst

Yareli Rojas-Aguirre Geovanni Sangabriel-Gordillo Israel Gonzalez-Mendez - Microwave synthesis and characterization of a supramolecular βCD-based crosslinked network

Gerardo Zaragoza-Galan1 EA Garciacutea Mackintosh D Chaacutevez-Flores A Camacho-Daacutevila L Manjarrez-Nevaacuterez Synthesis and characterization of meso-substituted boron dipyrromethenes (BODIPY)

Session 3- Inorganic and Hybrid Materials

Gerardo Barrera C Hugo Arcos G Carlos Espinosa Guillermo Carreoacuten G - Behavior and Removal of Inclusions in a Funnel Mold in Thin Slab Continuous Casting Use of Mathematical and Physical Simulations with the Aid of the Measured Vibrations with an Accelerometer

M Teresa Flores-Martiacutenez and Heriberto Pfeiffer - Comparative analysis of the CO2 capture properties for pure K-and Na-doped Li5AlO4

T Hernaacutendez L Madiacuten F J Garza Meacutendez - Synthesis and characterization of Pr1-xCaxFeO3 (x = 01 03 y 05) thin films and measurement of its electrical conductivity

Pascal G Lacroix Joeumllle Akl Isabelle Malfant Isabelle Sasaki Patricia Vicendo Mireille Blanchard-Desce Norberto Farfaacuten Rosa Santillaacuten Valerii Bukhanko Zoiumla Voitenko - Nitric oxide (NO) delivery from [RU(NO)] metal complexes with substituted terpyridine ligands

GA Lara-Rodriacuteguez N A Hernaacutendez-Zalasar E-Hernaacutendez-Mecinas ONovelo-Peralta IA-Figueroa - Study of grain refinement in aluminum alloys by adding AL-TI-C as grain refiner

Silva-G Angeacutelica Mariel Martiacutenez-G M Sonia Mireya - Synthesis and characterization of silver Nanoparticles using eichhornia crassipes

E Velaacutezquez Lozada T Torchynska M Kakazey M Vlasova - Photoluminescence and structure trend in mixture of ZNO and carbon nanoparticles during mechanical activation

E Velaacutezquez Lozada L Castantildeeda G M Camacho Gonzaacutelez - Aluminum concentration and substrate temperature on the physical characteristics of chemical sprayed ZNOAL thin solid films

Session 4- Coordination and Organometallic Chemistry and Catalysis

Jorge S Gancheff Karolina Soca Florencia Luzardo Rauacutel Chiozzone Pablo A Denis Paula EncisoMFernanda Cerdaacute Reza Dousti Andrea S S de Camargo - TiO2 nanoparticles sensitized with microwave-afforded Ru(II) complexes to investigate the photophysical response of antenna-complexes in DSSC solar cells

T Keith Hollis Theodore R Helgert Charles Edwin Webster Henry U Valle Allen G Oliver - CCC-NHC Tantalum Bis(imido) Reactivity Protonation or Rearrangement to a Mixed Unsymmetrical CCC-N-Heterocylic CarbeneN-Heterocyclic Dicarbene (CCC-NHC-NHDC) Pincer Tantalum Bis(imido) Complex

J Roberto PioquintominusMendoza Marcos Flores-Aacutelamo Rubeacuten A Toscano and David Morales-Morales - Hydrogen bonds in Novel Pd(II) Coordination complexes containing fluorinated Schiff Bases A Structural Study

Zertuche-Martiacutenez Sergio A Peralta Rodriacuteguez Reneacute D Peacuterez Camacho Odilia- Polymeric supports for heterogenization of zirconocene aluminohydrides

Session 5- Materials Science Applied to Industry

Luis Alberto Lightbourn Rojas Luis Amarillas Bueno Rubeacuten Leoacuten Chan - Rotaxanes Fulvalenes and Catenanes Optimization of Photosynthesis by Nanocomposites

PHOSPHORUS DENDRIMERS HYPERBRANCHED MACROMOLECULES FOR NANOSCIENCES

Anne-Marie Caminade12

1 CNRS LCC (Laboratoire de Chimie de Coordination) 205 route de Narbonne BP 44099 F-31077 Toulouse Cedex 4 France E-mail anne-mariecaminadelcc-toulousefr

2 Universiteacute de Toulouse UPS INPT F-31077 Toulouse Cedex 4 France

Dendrimers [1] are hyperbranched macromolecules constituted of repetitive monomeric units as polymers but they are never synthesized by polymerisation reactions Dendrimers have a perfectly defined 3D structure thanks to their step-by-step synthesis layer after layer Each time an additional layer of branching points is added a new generation is created Among the diverse types of dendrimers phosphorus-containing dendrimers in particular polyphosphorhydrazone dendrimers [2] occupy a special place due to their numerous properties as illustrated in Figure 1

Figure 1 Chemical structure of a second generation polyphosphorhydrazone dendrimer Properties and uses of this family of dendrimers depending on the nature of the terminal groups R

A few typical examples of these properties will be given below concerning catalysis nanomaterials and biologynanomedicine

Vol 1 Pag1

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Heidelberg

O N N O

1Cbzbox BOPA

2Boxmi

PyrrMeBOX

Vol 1 Pag5

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2bc gt95 98 ee

2ec gt95 99 ee

2cc gt95 98 ee

2gc gt95 99 ee

2ac gt95 99 ee

2oc gt95 94 eea

2jc gt95 94 ee

nC6H13

OHnC11H23

2kc gt95 95 ee

2lc gt95 99 ee

2mc gt95 99 ee

2ic 56 73 ee

2dc gt95 93 ee

2hc gt95 99 ee

2fc gt95 99 ee

2nc gt95 99 ee

Vol 1 Pag7

LigFe-OR

[LigFe-H]

FeLigH

LigFe-OAc

References

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Casting

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INTRODUCTION

EXPERIMENTAL

00E+00

20E+08

40E+08

60E+08

80E+08

10E+09

12E+09

050100150200

204 degC ECP

249 degC ECP

Vol 1 Pag14

AGTNCSUbench

400 degCAGTNCSU

00100200300400500600700800900

-50E+07

00E+00

50E+07

10E+08

15E+08

20E+08

25E+08

30E+08

35E+08

456585105

204 degC ECP

249 degC ECP

Vol 1 Pag15

-500E+06000E+00500E+06100E+07150E+07200E+07250E+07300E+07350E+07

0102030405060

204 degC ECP

249 degC ECP

-500E+07

000E+00

500E+07

100E+08

150E+08

95115135155175

204 degC ECP

249 degC ECP

Vol 1 Pag16

y = -43642x + 11255Rsup2 = 0986

00 05 10 15 20 25 30

(H+O)C

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CONCLUSIONS

REFERENCES [1]

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References

[2] Prog Polym Sci 2010 35 1350

[3] Polymer 2015 55 642

[5] Polymer 2002 43 2279

Vol 1 Pag21

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Introduction

1 0 60 15 2 0 30 30 3 0 0 15 4 1 0 30 5 1 30 15 6 1 60 30 7 2 30 0 8 1 30 15 9 1 60 0

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10 1 30 15 11 2 60 15 12 2 0 15 13 1 30 15 14 2 30 30 15 1 0 0 16 0 30 0 17 1 30 15

Vol 1 Pag24

SUMMARY

INTRODUCTION

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METHODOLOGY

RESULTS

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CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

Vol 1 Pag28

Introduction

Experimental

2O(12)Clay 5 wt-

Vol 1 Pag29

Time (min)

PAAcH2O (11)Clay

PAAcH2O (12)Clay

PAAcH2O (21)

PAAcH2O (11)

PAAcH2O (12)

0 0 0 0 0 0 000 5 5414 3424 6115 4210 4723 5000

10 6934 6373 7806 5365 6902 6758 20 10276 11288 12590 7477 8642 9848 30 12320 14644 15036 8831 10612 12727 60 22707 21627 24532 12629 15870 19227 90 30580 26746 28201 15631 20497 24576

120 34834 32203 32014 18619 24704 30076 180 41796 38610 39460 23147 31453 39318 240 42652 44271 46223 25976 35698 47364 360 43867 51627 51475 30066 42620 60712 480 44116 56610 54748 32390 46654 72121

1440 45829 69017 63993 36521 55449 124091 2880 46298 71627 66367 37397 58107 158485

Vol 1 Pag30

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Conclusions

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Nevaacuterez1

I Introduction

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II Metodology

Membrane synthesis

III Results

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IV Conclusion

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V References

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0 200 400 600 800 1000

Exposure time (hr)

HDPECu

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0 200 400 600 800 1000

Exposure time (hr)

HDPEMWCNTs

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0 200 400 600 800 1000

Exposure time (hr)

0 200 400 600 800 1000

Exposure time (hr)

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References

[1] Comp Sci Tech 2007 67 3071

[2] J Appl Polym Sci 2004 91 2781

[3] Mat Charac 2013 84 58

[4] Comp Part B Eng 2013 55 407

Vol 1 Pag41

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Neat PP 3735 4376 1684 1109 941 973

PPMWCNT 4201 4520 1686 1310 1043 988

Vol 1 Pag43

PPG 4023 4451 1680 1350 930 909

PPCB 4302 4553 1692 1256 902 888

Neat PP 349 2886

PPMWCNT 430 8616

PPG 421 9803

PPCB 442 9130

Vol 1 Pag44

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Introduction

Experimental

Vol 1 Pag47

1500 1350 1200 1050 900 750 6000

102030405060708090

100110120

Wavenumber (cm-1)

9511233-990

20 30 40 50 60 70

LaPO4 700 degC

LaPO4 600 degC

LaPO4 500 degC

LaPO4 400 degC

2(deg)

) (103

22) (1

23) (4

0 1000 2000 3000 4000 50000

40LaPO4

Dz = 2300 nm PDI = 12

Diameter (nm)

Vol 1 Pag48

400 450 500 550 600 650 7000

) LaPO4

2000 1800 1600 1400 1200 1000 800

C-O-CCH3

Wavelength (cm-1)

Commercial PMMA CH

C-O group

2000 1800 1600 1400 1200 1000 800

Synthesized PMMA CH

CH3CH3CH

Wavenumber (cm-1)

C-O group

200 300 400 500 600 700

Wavelength (nm)

Commercial PMMA

200 300 400 500 600 700

Wavelength (nm)

LaPO4 content (wt)

0 65 108 01 86 110 05 98 112 1 99 115

Vol 1 Pag49

Conclusions

References

Acknowledgements

Vol 1 Pag50

PETCHITOSAN BLENDS

ATDEq (1)

Vol 1 Pag51

2000 1750 1500 1250 1000 750

PETPLA 8515

C-OCH2

1768-1670

R-PETPLA 955

PET signalsC=O PLA

Wavenumber (cm-1)

3000 2500 2000 1500 1000

PETchitosan 991

PETchitosan 97525

PETchitosan 955

R-PETchitosan 991

R-PETchitosan 97525

Wavenumber (cm-1)

R-PETchitosan 955

C=O PET

2000 1800 1600 1400 1200 1000 800

PET-PLA 955

PET-PLA 8515

PET-PLA 9010

C-O1700 1747 C=O(a)

Wavenumber (cm-1)

2000 1800 1600 1400 1200 1000 800

R-PETPLA 8515

R-PETPLA 9010

R-PETPLA 955

Wavenumber (cm-1)2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715 1700

C=O(c)CH2

2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715

1700C=O(c) CH2

PETchitosan 955

Vol 1 Pag52

00 10x10-3 20x10-3 30x10-3 40x10-3

107 years103 years

76 years

91 years

58 years

54 years

143 years93 years

60 years

56 years

55 years

PETPLA 8515

PETPLA9010

PETPLA 955

R-PETPLA 8515

R-PETPLA9010

R-PETPLA 955

PETchitosan 955

PETchitosan 97525

PETchitosan 991

R-PETchitosan 955

R-PETchitosan 97525

R-PETchitosan 991

45 years

Vol 1 Pag53

PET 126 243 201 248 170 R-PET 245 205 227 245 156 PLA 161 126 150 120

R-PETChitosan 955 250 208 240 -

Vol 1 Pag54

ABSTRACT

INTRODUCTION

Vol 1 Pag55

Vol 1 Pag56

carbohydrate

CONCLUSIONS

AKNOWLEDGEMENTS

Vol 1 Pag57

Vol 1 Pag58

Vol 1 Pag59

Vol 1 Pag60

Vol 1 Pag61

References

Vol 1 Pag62

Vol 1 Pag63

Vol 1 Pag64

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

24 h NCC 1wt

01 52 00 220 012 0001

MCC 2wt

01 51 01 255 013 0015

MCC 5wt

01 51 01 360 023 0010

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

(mgAgP) DS

NCC 2wt

0217 39 09 0 005 0021

MCC 2wt

0213 23 01 5 013 0014

24 h MCC 4wt

0208 19 01 22 015 0005

MCC 6wt

0220 19 01 23 014 0010

MCC 8wt

0210 20 04 22 015 0004

Vol 1 Pag65

References

Vol 1 Pag66

ABSTRACT

INTRODUCTION

Vol 1 Pag67

Vol 1 Pag68

Vol 1 Pag69

Vol 1 Pag70

Vol 1 Pag71

catalyst

INTRODUCTION

Vol 1 Pag72

Vol 1 Pag73

r = 22 r = 09 r = 05

Yield () 71 100 100

E-factor (gg) 143 226 408

Vol 1 Pag74

Vol 1 Pag75

yarelirojasgmailcom

Abstract

Introduction

Vol 1 Pag76

Results

Vol 1 Pag77

Vol 1 Pag78

System Reactiontime

Yield()

βCD-CL-MW 45 min 57 316 873

Conclusions

References

Acknowledgment

Vol 1 Pag79

N NBF2

(Not isolated)

NH H O

R1234+

Conventional Method

2 eq 1 eq

Mechanochemical

Vol 1 Pag80

Reaction Steps

- No solvents

solvent

-Reaction time 1min

Reaction time 3h

and purity

Vol 1 Pag81

Vol 1 Pag82

Vol 1 Pag83

Vol 1 Pag84

1inc p

inc m inc pst

minus = minus

34174 25 (2)097411

minus = = minus

(grcm3)

Inclusion prototype

radius microm

0974 1 34 74 50-100

4 49 250125 500 5 612 219211 730 6 734 110147 500

Vol 1 Pag85

Vol 1 Pag86

REFERENCES

Vol 1 Pag87

Vol 1 Pag88

trfloresunammx

Vol 1 Pag89

100 200 300 400 500 600 700 800 900

Temperature (degC)

βminusLi5AlO4

chemisorption

] = -kt (2)

Vol 1 Pag90

0 20 40 60 80 100 120 140 160 180100

550 degC

650 degC

600 degC

Time (min)

700 degC

400 450 500 550 600 650 700

0025 βminusLi5AlO4

ln [Li5AlO4] =-k t

k (s-1

Temperature (degC)

for short times

13 = kD

Vol 1 Pag91

400 450 500 550 600 650 700

20x10-6

40x10-6

60x10-6

80x10-6

10x10-5

βminusLi5AlO4

kD t = 1-(1-α)13

k D (s-1

Temperature (degC)

Vol 1 Pag92

Vol 1 Pag93

Vol 1 Pag94

Vol 1 Pag95

Vol 1 Pag96

Scheme 1

Ru N OClN

Vol 1 Pag97

N ORR =

fluorene

Scheme 2

Vol 1 Pag98

Vol 1 Pag99

Perspectives

120590120590 =161205871205872119891119891(120583120583119890119890119890119890 minus 120583120583119892119892119892119892)2

References

4641-4678

Vol 1 Pag100

Abstract

Vol 1 Pag101

Free surface

Contact wheel

TiC α-Al

(a) (b) (c)

Vol 1 Pag102

(a) (b)

Vol 1 Pag103

Vol 1 Pag104

Vol 1 Pag105

m m 5 nm5 nm

5 10 20 30 40 50 600

Diameter (nm)

2 nm2 nm

a) (204)

5 nm5 nm

105deg25deg

250 300 350 400 450 500 550Ab

Wavelength (nm)

roots stems leaves

Vol 1 Pag106

DISCUSSION

CONCLUSION

Vol 1 Pag107

References

Vol 1 Pag108

ACTIVATION

Vol 1 Pag109

Vol 1 Pag110

Conclusion

Vol 1 Pag111

Vol 1 Pag112

Vol 1 Pag113

Vol 1 Pag114

Vol 1 Pag115

Vol 1 Pag116

Vol 1 Pag117

Vol 1 Pag118

Vol 1 Pag119

Introduction

Vol 1 Pag120

N NTaBu Bu

t-BuNHLi

TaBu Nt-But-BuN

N NBu Bu

supernatant

months

excess

Vol 1 Pag121

Vol 1 Pag122

TaBu Nt-But-BuN

N NBu Bu

N NTaBu Bu

355360365370375380385390395400405410415420425430435440445450455460465470475480485490495500f1 (ppm)

14 days 120 degC

4 days 160 degC

13 days 160 degC

reported[3c 16b 17]

Vol 1 Pag123

LiNR2N N

N NTaBu Bu

Nt-But-BuN

N TaBu

Nt-But-BuN

TaBu Nt-But-BuN

- HNR2

TaBu Nt-But-BuN

- R2N-

Vol 1 Pag124

Vol 1 Pag125

Vol 1 Pag126

Vol 1 Pag127

RefluxNa2SO4

48 h OHaHbO

F3C CF3

OHaHbO

F3C CF3

PdL1 PdL2

PdL3 PdL4

Vol 1 Pag128

Vol 1 Pag129

Vol 1 Pag130

References

Vol 1 Pag131

Vol 1 Pag132

Surfactant AA ()

Conversion ()

Z Potential (mV)

DP DLS (nm)

P(S-DVB-AA)

Vol 1 Pag133

(degC) Cristalinity

() Đ Mw (gmol)

Vol 1 Pag134

Vol 1 Pag135

Vol 1 Pag136

Vol 1 Pag137

ISSN 2448-590X

Plenary Lecture

Vol 1 Pag2

Vol 1 Pag3

Vol 1 Pag4

Heidelberg

O N N O

1Cbzbox BOPA

2Boxmi

PyrrMeBOX

Vol 1 Pag5

Vol 1 Pag6

2bc gt95 98 ee

2ec gt95 99 ee

2cc gt95 98 ee

2gc gt95 99 ee

2ac gt95 99 ee

2oc gt95 94 eea

2jc gt95 94 ee

nC6H13

OHnC11H23

2kc gt95 95 ee

2lc gt95 99 ee

2mc gt95 99 ee

2ic 56 73 ee

2dc gt95 93 ee

2hc gt95 99 ee

2fc gt95 99 ee

2nc gt95 99 ee

Vol 1 Pag7

LigFe-OR

[LigFe-H]

FeLigH

LigFe-OAc

References

Vol 1 Pag8

Vol 1 Pag9

Casting

Vol 1 Pag10

Vol 1 Pag11

Vol 1 Pag12

Vol 1 Pag13

INTRODUCTION

EXPERIMENTAL

00E+00

20E+08

40E+08

60E+08

80E+08

10E+09

12E+09

050100150200

204 degC ECP

249 degC ECP

Vol 1 Pag14

AGTNCSUbench

400 degCAGTNCSU

00100200300400500600700800900

-50E+07

00E+00

50E+07

10E+08

15E+08

20E+08

25E+08

30E+08

35E+08

456585105

204 degC ECP

249 degC ECP

Vol 1 Pag15

-500E+06000E+00500E+06100E+07150E+07200E+07250E+07300E+07350E+07

0102030405060

204 degC ECP

249 degC ECP

-500E+07

000E+00

500E+07

100E+08

150E+08

95115135155175

204 degC ECP

249 degC ECP

Vol 1 Pag16

y = -43642x + 11255Rsup2 = 0986

00 05 10 15 20 25 30

(H+O)C

Vol 1 Pag17

CONCLUSIONS

REFERENCES [1]

Vol 1 Pag18

Vol 1 Pag19

Vol 1 Pag20

References

[2] Prog Polym Sci 2010 35 1350

[3] Polymer 2015 55 642

[5] Polymer 2002 43 2279

Vol 1 Pag21

Vol 1 Pag22

Introduction

1 0 60 15 2 0 30 30 3 0 0 15 4 1 0 30 5 1 30 15 6 1 60 30 7 2 30 0 8 1 30 15 9 1 60 0

Vol 1 Pag23

10 1 30 15 11 2 60 15 12 2 0 15 13 1 30 15 14 2 30 30 15 1 0 0 16 0 30 0 17 1 30 15

Vol 1 Pag24

SUMMARY

INTRODUCTION

Vol 1 Pag25

METHODOLOGY

RESULTS

Vol 1 Pag26

Vol 1 Pag27

CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

Vol 1 Pag28

Introduction

Experimental

2O(12)Clay 5 wt-

Vol 1 Pag29

Time (min)

PAAcH2O (11)Clay

PAAcH2O (12)Clay

PAAcH2O (21)

PAAcH2O (11)

PAAcH2O (12)

0 0 0 0 0 0 000 5 5414 3424 6115 4210 4723 5000

10 6934 6373 7806 5365 6902 6758 20 10276 11288 12590 7477 8642 9848 30 12320 14644 15036 8831 10612 12727 60 22707 21627 24532 12629 15870 19227 90 30580 26746 28201 15631 20497 24576

120 34834 32203 32014 18619 24704 30076 180 41796 38610 39460 23147 31453 39318 240 42652 44271 46223 25976 35698 47364 360 43867 51627 51475 30066 42620 60712 480 44116 56610 54748 32390 46654 72121

1440 45829 69017 63993 36521 55449 124091 2880 46298 71627 66367 37397 58107 158485

Vol 1 Pag30

Vol 1 Pag31

Conclusions

Vol 1 Pag32

Nevaacuterez1

I Introduction

Vol 1 Pag33

II Metodology

Membrane synthesis

III Results

Vol 1 Pag34

IV Conclusion

Vol 1 Pag35

V References

Vol 1 Pag36

Vol 1 Pag37

0 200 400 600 800 1000

Exposure time (hr)

HDPECu

Vol 1 Pag38

0 200 400 600 800 1000

Exposure time (hr)

HDPEMWCNTs

Vol 1 Pag39

0 200 400 600 800 1000

Exposure time (hr)

0 200 400 600 800 1000

Exposure time (hr)

Vol 1 Pag40

References

[1] Comp Sci Tech 2007 67 3071

[2] J Appl Polym Sci 2004 91 2781

[3] Mat Charac 2013 84 58

[4] Comp Part B Eng 2013 55 407

Vol 1 Pag41

Vol 1 Pag42

Neat PP 3735 4376 1684 1109 941 973

PPMWCNT 4201 4520 1686 1310 1043 988

Vol 1 Pag43

PPG 4023 4451 1680 1350 930 909

PPCB 4302 4553 1692 1256 902 888

Neat PP 349 2886

PPMWCNT 430 8616

PPG 421 9803

PPCB 442 9130

Vol 1 Pag44

Vol 1 Pag45

Vol 1 Pag46

Introduction

Experimental

Vol 1 Pag47

1500 1350 1200 1050 900 750 6000

102030405060708090

100110120

Wavenumber (cm-1)

9511233-990

20 30 40 50 60 70

LaPO4 700 degC

LaPO4 600 degC

LaPO4 500 degC

LaPO4 400 degC

2(deg)

) (103

22) (1

23) (4

0 1000 2000 3000 4000 50000

40LaPO4

Dz = 2300 nm PDI = 12

Diameter (nm)

Vol 1 Pag48

400 450 500 550 600 650 7000

) LaPO4

2000 1800 1600 1400 1200 1000 800

C-O-CCH3

Wavelength (cm-1)

Commercial PMMA CH

C-O group

2000 1800 1600 1400 1200 1000 800

Synthesized PMMA CH

CH3CH3CH

Wavenumber (cm-1)

C-O group

200 300 400 500 600 700

Wavelength (nm)

Commercial PMMA

200 300 400 500 600 700

Wavelength (nm)

LaPO4 content (wt)

0 65 108 01 86 110 05 98 112 1 99 115

Vol 1 Pag49

Conclusions

References

Acknowledgements

Vol 1 Pag50

PETCHITOSAN BLENDS

ATDEq (1)

Vol 1 Pag51

2000 1750 1500 1250 1000 750

PETPLA 8515

C-OCH2

1768-1670

R-PETPLA 955

PET signalsC=O PLA

Wavenumber (cm-1)

3000 2500 2000 1500 1000

PETchitosan 991

PETchitosan 97525

PETchitosan 955

R-PETchitosan 991

R-PETchitosan 97525

Wavenumber (cm-1)

R-PETchitosan 955

C=O PET

2000 1800 1600 1400 1200 1000 800

PET-PLA 955

PET-PLA 8515

PET-PLA 9010

C-O1700 1747 C=O(a)

Wavenumber (cm-1)

2000 1800 1600 1400 1200 1000 800

R-PETPLA 8515

R-PETPLA 9010

R-PETPLA 955

Wavenumber (cm-1)2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715 1700

C=O(c)CH2

2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715

1700C=O(c) CH2

PETchitosan 955

Vol 1 Pag52

00 10x10-3 20x10-3 30x10-3 40x10-3

107 years103 years

76 years

91 years

58 years

54 years

143 years93 years

60 years

56 years

55 years

PETPLA 8515

PETPLA9010

PETPLA 955

R-PETPLA 8515

R-PETPLA9010

R-PETPLA 955

PETchitosan 955

PETchitosan 97525

PETchitosan 991

R-PETchitosan 955

R-PETchitosan 97525

R-PETchitosan 991

45 years

Vol 1 Pag53

PET 126 243 201 248 170 R-PET 245 205 227 245 156 PLA 161 126 150 120

R-PETChitosan 955 250 208 240 -

Vol 1 Pag54

ABSTRACT

INTRODUCTION

Vol 1 Pag55

Vol 1 Pag56

carbohydrate

CONCLUSIONS

AKNOWLEDGEMENTS

Vol 1 Pag57

Vol 1 Pag58

Vol 1 Pag59

Vol 1 Pag60

Vol 1 Pag61

References

Vol 1 Pag62

Vol 1 Pag63

Vol 1 Pag64

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

24 h NCC 1wt

01 52 00 220 012 0001

MCC 2wt

01 51 01 255 013 0015

MCC 5wt

01 51 01 360 023 0010

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

(mgAgP) DS

NCC 2wt

0217 39 09 0 005 0021

MCC 2wt

0213 23 01 5 013 0014

24 h MCC 4wt

0208 19 01 22 015 0005

MCC 6wt

0220 19 01 23 014 0010

MCC 8wt

0210 20 04 22 015 0004

Vol 1 Pag65

References

Vol 1 Pag66

ABSTRACT

INTRODUCTION

Vol 1 Pag67

Vol 1 Pag68

Vol 1 Pag69

Vol 1 Pag70

Vol 1 Pag71

catalyst

INTRODUCTION

Vol 1 Pag72

Vol 1 Pag73

r = 22 r = 09 r = 05

Yield () 71 100 100

E-factor (gg) 143 226 408

Vol 1 Pag74

Vol 1 Pag75

yarelirojasgmailcom

Abstract

Introduction

Vol 1 Pag76

Results

Vol 1 Pag77

Vol 1 Pag78

System Reactiontime

Yield()

βCD-CL-MW 45 min 57 316 873

Conclusions

References

Acknowledgment

Vol 1 Pag79

N NBF2

(Not isolated)

NH H O

R1234+

Conventional Method

2 eq 1 eq

Mechanochemical

Vol 1 Pag80

Reaction Steps

- No solvents

solvent

-Reaction time 1min

Reaction time 3h

and purity

Vol 1 Pag81

Vol 1 Pag82

Vol 1 Pag83

Vol 1 Pag84

1inc p

inc m inc pst

minus = minus

34174 25 (2)097411

minus = = minus

(grcm3)

Inclusion prototype

radius microm

0974 1 34 74 50-100

4 49 250125 500 5 612 219211 730 6 734 110147 500

Vol 1 Pag85

Vol 1 Pag86

REFERENCES

Vol 1 Pag87

Vol 1 Pag88

trfloresunammx

Vol 1 Pag89

100 200 300 400 500 600 700 800 900

Temperature (degC)

βminusLi5AlO4

chemisorption

] = -kt (2)

Vol 1 Pag90

0 20 40 60 80 100 120 140 160 180100

550 degC

650 degC

600 degC

Time (min)

700 degC

400 450 500 550 600 650 700

0025 βminusLi5AlO4

ln [Li5AlO4] =-k t

k (s-1

Temperature (degC)

for short times

13 = kD

Vol 1 Pag91

400 450 500 550 600 650 700

20x10-6

40x10-6

60x10-6

80x10-6

10x10-5

βminusLi5AlO4

kD t = 1-(1-α)13

k D (s-1

Temperature (degC)

Vol 1 Pag92

Vol 1 Pag93

Vol 1 Pag94

Vol 1 Pag95

Vol 1 Pag96

Scheme 1

Ru N OClN

Vol 1 Pag97

N ORR =

fluorene

Scheme 2

Vol 1 Pag98

Vol 1 Pag99

Perspectives

120590120590 =161205871205872119891119891(120583120583119890119890119890119890 minus 120583120583119892119892119892119892)2

References

4641-4678

Vol 1 Pag100

Abstract

Vol 1 Pag101

Free surface

Contact wheel

TiC α-Al

(a) (b) (c)

Vol 1 Pag102

(a) (b)

Vol 1 Pag103

Vol 1 Pag104

Vol 1 Pag105

m m 5 nm5 nm

5 10 20 30 40 50 600

Diameter (nm)

2 nm2 nm

a) (204)

5 nm5 nm

105deg25deg

250 300 350 400 450 500 550Ab

Wavelength (nm)

roots stems leaves

Vol 1 Pag106

DISCUSSION

CONCLUSION

Vol 1 Pag107

References

Vol 1 Pag108

ACTIVATION

Vol 1 Pag109

Vol 1 Pag110

Conclusion

Vol 1 Pag111

Vol 1 Pag112

Vol 1 Pag113

Vol 1 Pag114

Vol 1 Pag115

Vol 1 Pag116

Vol 1 Pag117

Vol 1 Pag118

Vol 1 Pag119

Introduction

Vol 1 Pag120

N NTaBu Bu

t-BuNHLi

TaBu Nt-But-BuN

N NBu Bu

supernatant

months

excess

Vol 1 Pag121

Vol 1 Pag122

TaBu Nt-But-BuN

N NBu Bu

N NTaBu Bu

355360365370375380385390395400405410415420425430435440445450455460465470475480485490495500f1 (ppm)

14 days 120 degC

4 days 160 degC

13 days 160 degC

reported[3c 16b 17]

Vol 1 Pag123

LiNR2N N

N NTaBu Bu

Nt-But-BuN

N TaBu

Nt-But-BuN

TaBu Nt-But-BuN

- HNR2

TaBu Nt-But-BuN

- R2N-

Vol 1 Pag124

Vol 1 Pag125

Vol 1 Pag126

Vol 1 Pag127

RefluxNa2SO4

48 h OHaHbO

F3C CF3

OHaHbO

F3C CF3

PdL1 PdL2

PdL3 PdL4

Vol 1 Pag128

Vol 1 Pag129

Vol 1 Pag130

References

Vol 1 Pag131

Vol 1 Pag132

Surfactant AA ()

Conversion ()

Z Potential (mV)

DP DLS (nm)

P(S-DVB-AA)

Vol 1 Pag133

(degC) Cristalinity

() Đ Mw (gmol)

Vol 1 Pag134

Vol 1 Pag135

Vol 1 Pag136

Vol 1 Pag137

ISSN 2448-590X

Plenary Lecture

Vol 1 Pag3

Vol 1 Pag4

Heidelberg

O N N O

1Cbzbox BOPA

2Boxmi

PyrrMeBOX

Vol 1 Pag5

Vol 1 Pag6

2bc gt95 98 ee

2ec gt95 99 ee

2cc gt95 98 ee

2gc gt95 99 ee

2ac gt95 99 ee

2oc gt95 94 eea

2jc gt95 94 ee

nC6H13

OHnC11H23

2kc gt95 95 ee

2lc gt95 99 ee

2mc gt95 99 ee

2ic 56 73 ee

2dc gt95 93 ee

2hc gt95 99 ee

2fc gt95 99 ee

2nc gt95 99 ee

Vol 1 Pag7

LigFe-OR

[LigFe-H]

FeLigH

LigFe-OAc

References

Vol 1 Pag8

Vol 1 Pag9

Casting

Vol 1 Pag10

Vol 1 Pag11

Vol 1 Pag12

Vol 1 Pag13

INTRODUCTION

EXPERIMENTAL

00E+00

20E+08

40E+08

60E+08

80E+08

10E+09

12E+09

050100150200

204 degC ECP

249 degC ECP

Vol 1 Pag14

AGTNCSUbench

400 degCAGTNCSU

00100200300400500600700800900

-50E+07

00E+00

50E+07

10E+08

15E+08

20E+08

25E+08

30E+08

35E+08

456585105

204 degC ECP

249 degC ECP

Vol 1 Pag15

-500E+06000E+00500E+06100E+07150E+07200E+07250E+07300E+07350E+07

0102030405060

204 degC ECP

249 degC ECP

-500E+07

000E+00

500E+07

100E+08

150E+08

95115135155175

204 degC ECP

249 degC ECP

Vol 1 Pag16

y = -43642x + 11255Rsup2 = 0986

00 05 10 15 20 25 30

(H+O)C

Vol 1 Pag17

CONCLUSIONS

REFERENCES [1]

Vol 1 Pag18

Vol 1 Pag19

Vol 1 Pag20

References

[2] Prog Polym Sci 2010 35 1350

[3] Polymer 2015 55 642

[5] Polymer 2002 43 2279

Vol 1 Pag21

Vol 1 Pag22

Introduction

1 0 60 15 2 0 30 30 3 0 0 15 4 1 0 30 5 1 30 15 6 1 60 30 7 2 30 0 8 1 30 15 9 1 60 0

Vol 1 Pag23

10 1 30 15 11 2 60 15 12 2 0 15 13 1 30 15 14 2 30 30 15 1 0 0 16 0 30 0 17 1 30 15

Vol 1 Pag24

SUMMARY

INTRODUCTION

Vol 1 Pag25

METHODOLOGY

RESULTS

Vol 1 Pag26

Vol 1 Pag27

CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

Vol 1 Pag28

Introduction

Experimental

2O(12)Clay 5 wt-

Vol 1 Pag29

Time (min)

PAAcH2O (11)Clay

PAAcH2O (12)Clay

PAAcH2O (21)

PAAcH2O (11)

PAAcH2O (12)

0 0 0 0 0 0 000 5 5414 3424 6115 4210 4723 5000

10 6934 6373 7806 5365 6902 6758 20 10276 11288 12590 7477 8642 9848 30 12320 14644 15036 8831 10612 12727 60 22707 21627 24532 12629 15870 19227 90 30580 26746 28201 15631 20497 24576

120 34834 32203 32014 18619 24704 30076 180 41796 38610 39460 23147 31453 39318 240 42652 44271 46223 25976 35698 47364 360 43867 51627 51475 30066 42620 60712 480 44116 56610 54748 32390 46654 72121

1440 45829 69017 63993 36521 55449 124091 2880 46298 71627 66367 37397 58107 158485

Vol 1 Pag30

Vol 1 Pag31

Conclusions

Vol 1 Pag32

Nevaacuterez1

I Introduction

Vol 1 Pag33

II Metodology

Membrane synthesis

III Results

Vol 1 Pag34

IV Conclusion

Vol 1 Pag35

V References

Vol 1 Pag36

Vol 1 Pag37

0 200 400 600 800 1000

Exposure time (hr)

HDPECu

Vol 1 Pag38

0 200 400 600 800 1000

Exposure time (hr)

HDPEMWCNTs

Vol 1 Pag39

0 200 400 600 800 1000

Exposure time (hr)

0 200 400 600 800 1000

Exposure time (hr)

Vol 1 Pag40

References

[1] Comp Sci Tech 2007 67 3071

[2] J Appl Polym Sci 2004 91 2781

[3] Mat Charac 2013 84 58

[4] Comp Part B Eng 2013 55 407

Vol 1 Pag41

Vol 1 Pag42

Neat PP 3735 4376 1684 1109 941 973

PPMWCNT 4201 4520 1686 1310 1043 988

Vol 1 Pag43

PPG 4023 4451 1680 1350 930 909

PPCB 4302 4553 1692 1256 902 888

Neat PP 349 2886

PPMWCNT 430 8616

PPG 421 9803

PPCB 442 9130

Vol 1 Pag44

Vol 1 Pag45

Vol 1 Pag46

Introduction

Experimental

Vol 1 Pag47

1500 1350 1200 1050 900 750 6000

102030405060708090

100110120

Wavenumber (cm-1)

9511233-990

20 30 40 50 60 70

LaPO4 700 degC

LaPO4 600 degC

LaPO4 500 degC

LaPO4 400 degC

2(deg)

) (103

22) (1

23) (4

0 1000 2000 3000 4000 50000

40LaPO4

Dz = 2300 nm PDI = 12

Diameter (nm)

Vol 1 Pag48

400 450 500 550 600 650 7000

) LaPO4

2000 1800 1600 1400 1200 1000 800

C-O-CCH3

Wavelength (cm-1)

Commercial PMMA CH

C-O group

2000 1800 1600 1400 1200 1000 800

Synthesized PMMA CH

CH3CH3CH

Wavenumber (cm-1)

C-O group

200 300 400 500 600 700

Wavelength (nm)

Commercial PMMA

200 300 400 500 600 700

Wavelength (nm)

LaPO4 content (wt)

0 65 108 01 86 110 05 98 112 1 99 115

Vol 1 Pag49

Conclusions

References

Acknowledgements

Vol 1 Pag50

PETCHITOSAN BLENDS

ATDEq (1)

Vol 1 Pag51

2000 1750 1500 1250 1000 750

PETPLA 8515

C-OCH2

1768-1670

R-PETPLA 955

PET signalsC=O PLA

Wavenumber (cm-1)

3000 2500 2000 1500 1000

PETchitosan 991

PETchitosan 97525

PETchitosan 955

R-PETchitosan 991

R-PETchitosan 97525

Wavenumber (cm-1)

R-PETchitosan 955

C=O PET

2000 1800 1600 1400 1200 1000 800

PET-PLA 955

PET-PLA 8515

PET-PLA 9010

C-O1700 1747 C=O(a)

Wavenumber (cm-1)

2000 1800 1600 1400 1200 1000 800

R-PETPLA 8515

R-PETPLA 9010

R-PETPLA 955

Wavenumber (cm-1)2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715 1700

C=O(c)CH2

2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715

1700C=O(c) CH2

PETchitosan 955

Vol 1 Pag52

00 10x10-3 20x10-3 30x10-3 40x10-3

107 years103 years

76 years

91 years

58 years

54 years

143 years93 years

60 years

56 years

55 years

PETPLA 8515

PETPLA9010

PETPLA 955

R-PETPLA 8515

R-PETPLA9010

R-PETPLA 955

PETchitosan 955

PETchitosan 97525

PETchitosan 991

R-PETchitosan 955

R-PETchitosan 97525

R-PETchitosan 991

45 years

Vol 1 Pag53

PET 126 243 201 248 170 R-PET 245 205 227 245 156 PLA 161 126 150 120

R-PETChitosan 955 250 208 240 -

Vol 1 Pag54

ABSTRACT

INTRODUCTION

Vol 1 Pag55

Vol 1 Pag56

carbohydrate

CONCLUSIONS

AKNOWLEDGEMENTS

Vol 1 Pag57

Vol 1 Pag58

Vol 1 Pag59

Vol 1 Pag60

Vol 1 Pag61

References

Vol 1 Pag62

Vol 1 Pag63

Vol 1 Pag64

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

24 h NCC 1wt

01 52 00 220 012 0001

MCC 2wt

01 51 01 255 013 0015

MCC 5wt

01 51 01 360 023 0010

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

(mgAgP) DS

NCC 2wt

0217 39 09 0 005 0021

MCC 2wt

0213 23 01 5 013 0014

24 h MCC 4wt

0208 19 01 22 015 0005

MCC 6wt

0220 19 01 23 014 0010

MCC 8wt

0210 20 04 22 015 0004

Vol 1 Pag65

References

Vol 1 Pag66

ABSTRACT

INTRODUCTION

Vol 1 Pag67

Vol 1 Pag68

Vol 1 Pag69

Vol 1 Pag70

Vol 1 Pag71

catalyst

INTRODUCTION

Vol 1 Pag72

Vol 1 Pag73

r = 22 r = 09 r = 05

Yield () 71 100 100

E-factor (gg) 143 226 408

Vol 1 Pag74

Vol 1 Pag75

yarelirojasgmailcom

Abstract

Introduction

Vol 1 Pag76

Results

Vol 1 Pag77

Vol 1 Pag78

System Reactiontime

Yield()

βCD-CL-MW 45 min 57 316 873

Conclusions

References

Acknowledgment

Vol 1 Pag79

N NBF2

(Not isolated)

NH H O

R1234+

Conventional Method

2 eq 1 eq

Mechanochemical

Vol 1 Pag80

Reaction Steps

- No solvents

solvent

-Reaction time 1min

Reaction time 3h

and purity

Vol 1 Pag81

Vol 1 Pag82

Vol 1 Pag83

Vol 1 Pag84

1inc p

inc m inc pst

minus = minus

34174 25 (2)097411

minus = = minus

(grcm3)

Inclusion prototype

radius microm

0974 1 34 74 50-100

4 49 250125 500 5 612 219211 730 6 734 110147 500

Vol 1 Pag85

Vol 1 Pag86

REFERENCES

Vol 1 Pag87

Vol 1 Pag88

trfloresunammx

Vol 1 Pag89

100 200 300 400 500 600 700 800 900

Temperature (degC)

βminusLi5AlO4

chemisorption

] = -kt (2)

Vol 1 Pag90

0 20 40 60 80 100 120 140 160 180100

550 degC

650 degC

600 degC

Time (min)

700 degC

400 450 500 550 600 650 700

0025 βminusLi5AlO4

ln [Li5AlO4] =-k t

k (s-1

Temperature (degC)

for short times

13 = kD

Vol 1 Pag91

400 450 500 550 600 650 700

20x10-6

40x10-6

60x10-6

80x10-6

10x10-5

βminusLi5AlO4

kD t = 1-(1-α)13

k D (s-1

Temperature (degC)

Vol 1 Pag92

Vol 1 Pag93

Vol 1 Pag94

Vol 1 Pag95

Vol 1 Pag96

Scheme 1

Ru N OClN

Vol 1 Pag97

N ORR =

fluorene

Scheme 2

Vol 1 Pag98

Vol 1 Pag99

Perspectives

120590120590 =161205871205872119891119891(120583120583119890119890119890119890 minus 120583120583119892119892119892119892)2

References

4641-4678

Vol 1 Pag100

Abstract

Vol 1 Pag101

Free surface

Contact wheel

TiC α-Al

(a) (b) (c)

Vol 1 Pag102

(a) (b)

Vol 1 Pag103

Vol 1 Pag104

Vol 1 Pag105

m m 5 nm5 nm

5 10 20 30 40 50 600

Diameter (nm)

2 nm2 nm

a) (204)

5 nm5 nm

105deg25deg

250 300 350 400 450 500 550Ab

Wavelength (nm)

roots stems leaves

Vol 1 Pag106

DISCUSSION

CONCLUSION

Vol 1 Pag107

References

Vol 1 Pag108

ACTIVATION

Vol 1 Pag109

Vol 1 Pag110

Conclusion

Vol 1 Pag111

Vol 1 Pag112

Vol 1 Pag113

Vol 1 Pag114

Vol 1 Pag115

Vol 1 Pag116

Vol 1 Pag117

Vol 1 Pag118

Vol 1 Pag119

Introduction

Vol 1 Pag120

N NTaBu Bu

t-BuNHLi

TaBu Nt-But-BuN

N NBu Bu

supernatant

months

excess

Vol 1 Pag121

Vol 1 Pag122

TaBu Nt-But-BuN

N NBu Bu

N NTaBu Bu

355360365370375380385390395400405410415420425430435440445450455460465470475480485490495500f1 (ppm)

14 days 120 degC

4 days 160 degC

13 days 160 degC

reported[3c 16b 17]

Vol 1 Pag123

LiNR2N N

N NTaBu Bu

Nt-But-BuN

N TaBu

Nt-But-BuN

TaBu Nt-But-BuN

- HNR2

TaBu Nt-But-BuN

- R2N-

Vol 1 Pag124

Vol 1 Pag125

Vol 1 Pag126

Vol 1 Pag127

RefluxNa2SO4

48 h OHaHbO

F3C CF3

OHaHbO

F3C CF3

PdL1 PdL2

PdL3 PdL4

Vol 1 Pag128

Vol 1 Pag129

Vol 1 Pag130

References

Vol 1 Pag131

Vol 1 Pag132

Surfactant AA ()

Conversion ()

Z Potential (mV)

DP DLS (nm)

P(S-DVB-AA)

Vol 1 Pag133

(degC) Cristalinity

() Đ Mw (gmol)

Vol 1 Pag134

Vol 1 Pag135

Vol 1 Pag136

Vol 1 Pag137

ISSN 2448-590X

Plenary Lecture

Vol 1 Pag4

Heidelberg

O N N O

1Cbzbox BOPA

2Boxmi

PyrrMeBOX

Vol 1 Pag5

Vol 1 Pag6

2bc gt95 98 ee

2ec gt95 99 ee

2cc gt95 98 ee

2gc gt95 99 ee

2ac gt95 99 ee

2oc gt95 94 eea

2jc gt95 94 ee

nC6H13

OHnC11H23

2kc gt95 95 ee

2lc gt95 99 ee

2mc gt95 99 ee

2ic 56 73 ee

2dc gt95 93 ee

2hc gt95 99 ee

2fc gt95 99 ee

2nc gt95 99 ee

Vol 1 Pag7

LigFe-OR

[LigFe-H]

FeLigH

LigFe-OAc

References

Vol 1 Pag8

Vol 1 Pag9

Casting

Vol 1 Pag10

Vol 1 Pag11

Vol 1 Pag12

Vol 1 Pag13

INTRODUCTION

EXPERIMENTAL

00E+00

20E+08

40E+08

60E+08

80E+08

10E+09

12E+09

050100150200

204 degC ECP

249 degC ECP

Vol 1 Pag14

AGTNCSUbench

400 degCAGTNCSU

00100200300400500600700800900

-50E+07

00E+00

50E+07

10E+08

15E+08

20E+08

25E+08

30E+08

35E+08

456585105

204 degC ECP

249 degC ECP

Vol 1 Pag15

-500E+06000E+00500E+06100E+07150E+07200E+07250E+07300E+07350E+07

0102030405060

204 degC ECP

249 degC ECP

-500E+07

000E+00

500E+07

100E+08

150E+08

95115135155175

204 degC ECP

249 degC ECP

Vol 1 Pag16

y = -43642x + 11255Rsup2 = 0986

00 05 10 15 20 25 30

(H+O)C

Vol 1 Pag17

CONCLUSIONS

REFERENCES [1]

Vol 1 Pag18

Vol 1 Pag19

Vol 1 Pag20

References

[2] Prog Polym Sci 2010 35 1350

[3] Polymer 2015 55 642

[5] Polymer 2002 43 2279

Vol 1 Pag21

Vol 1 Pag22

Introduction

1 0 60 15 2 0 30 30 3 0 0 15 4 1 0 30 5 1 30 15 6 1 60 30 7 2 30 0 8 1 30 15 9 1 60 0

Vol 1 Pag23

10 1 30 15 11 2 60 15 12 2 0 15 13 1 30 15 14 2 30 30 15 1 0 0 16 0 30 0 17 1 30 15

Vol 1 Pag24

SUMMARY

INTRODUCTION

Vol 1 Pag25

METHODOLOGY

RESULTS

Vol 1 Pag26

Vol 1 Pag27

CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

Vol 1 Pag28

Introduction

Experimental

2O(12)Clay 5 wt-

Vol 1 Pag29

Time (min)

PAAcH2O (11)Clay

PAAcH2O (12)Clay

PAAcH2O (21)

PAAcH2O (11)

PAAcH2O (12)

0 0 0 0 0 0 000 5 5414 3424 6115 4210 4723 5000

10 6934 6373 7806 5365 6902 6758 20 10276 11288 12590 7477 8642 9848 30 12320 14644 15036 8831 10612 12727 60 22707 21627 24532 12629 15870 19227 90 30580 26746 28201 15631 20497 24576

120 34834 32203 32014 18619 24704 30076 180 41796 38610 39460 23147 31453 39318 240 42652 44271 46223 25976 35698 47364 360 43867 51627 51475 30066 42620 60712 480 44116 56610 54748 32390 46654 72121

1440 45829 69017 63993 36521 55449 124091 2880 46298 71627 66367 37397 58107 158485

Vol 1 Pag30

Vol 1 Pag31

Conclusions

Vol 1 Pag32

Nevaacuterez1

I Introduction

Vol 1 Pag33

II Metodology

Membrane synthesis

III Results

Vol 1 Pag34

IV Conclusion

Vol 1 Pag35

V References

Vol 1 Pag36

Vol 1 Pag37

0 200 400 600 800 1000

Exposure time (hr)

HDPECu

Vol 1 Pag38

0 200 400 600 800 1000

Exposure time (hr)

HDPEMWCNTs

Vol 1 Pag39

0 200 400 600 800 1000

Exposure time (hr)

0 200 400 600 800 1000

Exposure time (hr)

Vol 1 Pag40

References

[1] Comp Sci Tech 2007 67 3071

[2] J Appl Polym Sci 2004 91 2781

[3] Mat Charac 2013 84 58

[4] Comp Part B Eng 2013 55 407

Vol 1 Pag41

Vol 1 Pag42

Neat PP 3735 4376 1684 1109 941 973

PPMWCNT 4201 4520 1686 1310 1043 988

Vol 1 Pag43

PPG 4023 4451 1680 1350 930 909

PPCB 4302 4553 1692 1256 902 888

Neat PP 349 2886

PPMWCNT 430 8616

PPG 421 9803

PPCB 442 9130

Vol 1 Pag44

Vol 1 Pag45

Vol 1 Pag46

Introduction

Experimental

Vol 1 Pag47

1500 1350 1200 1050 900 750 6000

102030405060708090

100110120

Wavenumber (cm-1)

9511233-990

20 30 40 50 60 70

LaPO4 700 degC

LaPO4 600 degC

LaPO4 500 degC

LaPO4 400 degC

2(deg)

) (103

22) (1

23) (4

0 1000 2000 3000 4000 50000

40LaPO4

Dz = 2300 nm PDI = 12

Diameter (nm)

Vol 1 Pag48

400 450 500 550 600 650 7000

) LaPO4

2000 1800 1600 1400 1200 1000 800

C-O-CCH3

Wavelength (cm-1)

Commercial PMMA CH

C-O group

2000 1800 1600 1400 1200 1000 800

Synthesized PMMA CH

CH3CH3CH

Wavenumber (cm-1)

C-O group

200 300 400 500 600 700

Wavelength (nm)

Commercial PMMA

200 300 400 500 600 700

Wavelength (nm)

LaPO4 content (wt)

0 65 108 01 86 110 05 98 112 1 99 115

Vol 1 Pag49

Conclusions

References

Acknowledgements

Vol 1 Pag50

PETCHITOSAN BLENDS

ATDEq (1)

Vol 1 Pag51

2000 1750 1500 1250 1000 750

PETPLA 8515

C-OCH2

1768-1670

R-PETPLA 955

PET signalsC=O PLA

Wavenumber (cm-1)

3000 2500 2000 1500 1000

PETchitosan 991

PETchitosan 97525

PETchitosan 955

R-PETchitosan 991

R-PETchitosan 97525

Wavenumber (cm-1)

R-PETchitosan 955

C=O PET

2000 1800 1600 1400 1200 1000 800

PET-PLA 955

PET-PLA 8515

PET-PLA 9010

C-O1700 1747 C=O(a)

Wavenumber (cm-1)

2000 1800 1600 1400 1200 1000 800

R-PETPLA 8515

R-PETPLA 9010

R-PETPLA 955

Wavenumber (cm-1)2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715 1700

C=O(c)CH2

2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715

1700C=O(c) CH2

PETchitosan 955

Vol 1 Pag52

00 10x10-3 20x10-3 30x10-3 40x10-3

107 years103 years

76 years

91 years

58 years

54 years

143 years93 years

60 years

56 years

55 years

PETPLA 8515

PETPLA9010

PETPLA 955

R-PETPLA 8515

R-PETPLA9010

R-PETPLA 955

PETchitosan 955

PETchitosan 97525

PETchitosan 991

R-PETchitosan 955

R-PETchitosan 97525

R-PETchitosan 991

45 years

Vol 1 Pag53

PET 126 243 201 248 170 R-PET 245 205 227 245 156 PLA 161 126 150 120

R-PETChitosan 955 250 208 240 -

Vol 1 Pag54

ABSTRACT

INTRODUCTION

Vol 1 Pag55

Vol 1 Pag56

carbohydrate

CONCLUSIONS

AKNOWLEDGEMENTS

Vol 1 Pag57

Vol 1 Pag58

Vol 1 Pag59

Vol 1 Pag60

Vol 1 Pag61

References

Vol 1 Pag62

Vol 1 Pag63

Vol 1 Pag64

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

24 h NCC 1wt

01 52 00 220 012 0001

MCC 2wt

01 51 01 255 013 0015

MCC 5wt

01 51 01 360 023 0010

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

(mgAgP) DS

NCC 2wt

0217 39 09 0 005 0021

MCC 2wt

0213 23 01 5 013 0014

24 h MCC 4wt

0208 19 01 22 015 0005

MCC 6wt

0220 19 01 23 014 0010

MCC 8wt

0210 20 04 22 015 0004

Vol 1 Pag65

References

Vol 1 Pag66

ABSTRACT

INTRODUCTION

Vol 1 Pag67

Vol 1 Pag68

Vol 1 Pag69

Vol 1 Pag70

Vol 1 Pag71

catalyst

INTRODUCTION

Vol 1 Pag72

Vol 1 Pag73

r = 22 r = 09 r = 05

Yield () 71 100 100

E-factor (gg) 143 226 408

Vol 1 Pag74

Vol 1 Pag75

yarelirojasgmailcom

Abstract

Introduction

Vol 1 Pag76

Results

Vol 1 Pag77

Vol 1 Pag78

System Reactiontime

Yield()

βCD-CL-MW 45 min 57 316 873

Conclusions

References

Acknowledgment

Vol 1 Pag79

N NBF2

(Not isolated)

NH H O

R1234+

Conventional Method

2 eq 1 eq

Mechanochemical

Vol 1 Pag80

Reaction Steps

- No solvents

solvent

-Reaction time 1min

Reaction time 3h

and purity

Vol 1 Pag81

Vol 1 Pag82

Vol 1 Pag83

Vol 1 Pag84

1inc p

inc m inc pst

minus = minus

34174 25 (2)097411

minus = = minus

(grcm3)

Inclusion prototype

radius microm

0974 1 34 74 50-100

4 49 250125 500 5 612 219211 730 6 734 110147 500

Vol 1 Pag85

Vol 1 Pag86

REFERENCES

Vol 1 Pag87

Vol 1 Pag88

trfloresunammx

Vol 1 Pag89

100 200 300 400 500 600 700 800 900

Temperature (degC)

βminusLi5AlO4

chemisorption

] = -kt (2)

Vol 1 Pag90

0 20 40 60 80 100 120 140 160 180100

550 degC

650 degC

600 degC

Time (min)

700 degC

400 450 500 550 600 650 700

0025 βminusLi5AlO4

ln [Li5AlO4] =-k t

k (s-1

Temperature (degC)

for short times

13 = kD

Vol 1 Pag91

400 450 500 550 600 650 700

20x10-6

40x10-6

60x10-6

80x10-6

10x10-5

βminusLi5AlO4

kD t = 1-(1-α)13

k D (s-1

Temperature (degC)

Vol 1 Pag92

Vol 1 Pag93

Vol 1 Pag94

Vol 1 Pag95

Vol 1 Pag96

Scheme 1

Ru N OClN

Vol 1 Pag97

N ORR =

fluorene

Scheme 2

Vol 1 Pag98

Vol 1 Pag99

Perspectives

120590120590 =161205871205872119891119891(120583120583119890119890119890119890 minus 120583120583119892119892119892119892)2

References

4641-4678

Vol 1 Pag100

Abstract

Vol 1 Pag101

Free surface

Contact wheel

TiC α-Al

(a) (b) (c)

Vol 1 Pag102

(a) (b)

Vol 1 Pag103

Vol 1 Pag104

Vol 1 Pag105

m m 5 nm5 nm

5 10 20 30 40 50 600

Diameter (nm)

2 nm2 nm

a) (204)

5 nm5 nm

105deg25deg

250 300 350 400 450 500 550Ab

Wavelength (nm)

roots stems leaves

Vol 1 Pag106

DISCUSSION

CONCLUSION

Vol 1 Pag107

References

Vol 1 Pag108

ACTIVATION

Vol 1 Pag109

Vol 1 Pag110

Conclusion

Vol 1 Pag111

Vol 1 Pag112

Vol 1 Pag113

Vol 1 Pag114

Vol 1 Pag115

Vol 1 Pag116

Vol 1 Pag117

Vol 1 Pag118

Vol 1 Pag119

Introduction

Vol 1 Pag120

N NTaBu Bu

t-BuNHLi

TaBu Nt-But-BuN

N NBu Bu

supernatant

months

excess

Vol 1 Pag121

Vol 1 Pag122

TaBu Nt-But-BuN

N NBu Bu

N NTaBu Bu

355360365370375380385390395400405410415420425430435440445450455460465470475480485490495500f1 (ppm)

14 days 120 degC

4 days 160 degC

13 days 160 degC

reported[3c 16b 17]

Vol 1 Pag123

LiNR2N N

N NTaBu Bu

Nt-But-BuN

N TaBu

Nt-But-BuN

TaBu Nt-But-BuN

- HNR2

TaBu Nt-But-BuN

- R2N-

Vol 1 Pag124

Vol 1 Pag125

Vol 1 Pag126

Vol 1 Pag127

RefluxNa2SO4

48 h OHaHbO

F3C CF3

OHaHbO

F3C CF3

PdL1 PdL2

PdL3 PdL4

Vol 1 Pag128

Vol 1 Pag129

Vol 1 Pag130

References

Vol 1 Pag131

Vol 1 Pag132

Surfactant AA ()

Conversion ()

Z Potential (mV)

DP DLS (nm)

P(S-DVB-AA)

Vol 1 Pag133

(degC) Cristalinity

() Đ Mw (gmol)

Vol 1 Pag134

Vol 1 Pag135

Vol 1 Pag136

Vol 1 Pag137

ISSN 2448-590X

Plenary Lecture

Heidelberg

O N N O

1Cbzbox BOPA

2Boxmi

PyrrMeBOX

Vol 1 Pag5

Vol 1 Pag6

2bc gt95 98 ee

2ec gt95 99 ee

2cc gt95 98 ee

2gc gt95 99 ee

2ac gt95 99 ee

2oc gt95 94 eea

2jc gt95 94 ee

nC6H13

OHnC11H23

2kc gt95 95 ee

2lc gt95 99 ee

2mc gt95 99 ee

2ic 56 73 ee

2dc gt95 93 ee

2hc gt95 99 ee

2fc gt95 99 ee

2nc gt95 99 ee

Vol 1 Pag7

LigFe-OR

[LigFe-H]

FeLigH

LigFe-OAc

References

Vol 1 Pag8

Vol 1 Pag9

Casting

Vol 1 Pag10

Vol 1 Pag11

Vol 1 Pag12

Vol 1 Pag13

INTRODUCTION

EXPERIMENTAL

00E+00

20E+08

40E+08

60E+08

80E+08

10E+09

12E+09

050100150200

204 degC ECP

249 degC ECP

Vol 1 Pag14

AGTNCSUbench

400 degCAGTNCSU

00100200300400500600700800900

-50E+07

00E+00

50E+07

10E+08

15E+08

20E+08

25E+08

30E+08

35E+08

456585105

204 degC ECP

249 degC ECP

Vol 1 Pag15

-500E+06000E+00500E+06100E+07150E+07200E+07250E+07300E+07350E+07

0102030405060

204 degC ECP

249 degC ECP

-500E+07

000E+00

500E+07

100E+08

150E+08

95115135155175

204 degC ECP

249 degC ECP

Vol 1 Pag16

y = -43642x + 11255Rsup2 = 0986

00 05 10 15 20 25 30

(H+O)C

Vol 1 Pag17

CONCLUSIONS

REFERENCES [1]

Vol 1 Pag18

Vol 1 Pag19

Vol 1 Pag20

References

[2] Prog Polym Sci 2010 35 1350

[3] Polymer 2015 55 642

[5] Polymer 2002 43 2279

Vol 1 Pag21

Vol 1 Pag22

Introduction

1 0 60 15 2 0 30 30 3 0 0 15 4 1 0 30 5 1 30 15 6 1 60 30 7 2 30 0 8 1 30 15 9 1 60 0

Vol 1 Pag23

10 1 30 15 11 2 60 15 12 2 0 15 13 1 30 15 14 2 30 30 15 1 0 0 16 0 30 0 17 1 30 15

Vol 1 Pag24

SUMMARY

INTRODUCTION

Vol 1 Pag25

METHODOLOGY

RESULTS

Vol 1 Pag26

Vol 1 Pag27

CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

Vol 1 Pag28

Introduction

Experimental

2O(12)Clay 5 wt-

Vol 1 Pag29

Time (min)

PAAcH2O (11)Clay

PAAcH2O (12)Clay

PAAcH2O (21)

PAAcH2O (11)

PAAcH2O (12)

0 0 0 0 0 0 000 5 5414 3424 6115 4210 4723 5000

10 6934 6373 7806 5365 6902 6758 20 10276 11288 12590 7477 8642 9848 30 12320 14644 15036 8831 10612 12727 60 22707 21627 24532 12629 15870 19227 90 30580 26746 28201 15631 20497 24576

120 34834 32203 32014 18619 24704 30076 180 41796 38610 39460 23147 31453 39318 240 42652 44271 46223 25976 35698 47364 360 43867 51627 51475 30066 42620 60712 480 44116 56610 54748 32390 46654 72121

1440 45829 69017 63993 36521 55449 124091 2880 46298 71627 66367 37397 58107 158485

Vol 1 Pag30

Vol 1 Pag31

Conclusions

Vol 1 Pag32

Nevaacuterez1

I Introduction

Vol 1 Pag33

II Metodology

Membrane synthesis

III Results

Vol 1 Pag34

IV Conclusion

Vol 1 Pag35

V References

Vol 1 Pag36

Vol 1 Pag37

0 200 400 600 800 1000

Exposure time (hr)

HDPECu

Vol 1 Pag38

0 200 400 600 800 1000

Exposure time (hr)

HDPEMWCNTs

Vol 1 Pag39

0 200 400 600 800 1000

Exposure time (hr)

0 200 400 600 800 1000

Exposure time (hr)

Vol 1 Pag40

References

[1] Comp Sci Tech 2007 67 3071

[2] J Appl Polym Sci 2004 91 2781

[3] Mat Charac 2013 84 58

[4] Comp Part B Eng 2013 55 407

Vol 1 Pag41

Vol 1 Pag42

Neat PP 3735 4376 1684 1109 941 973

PPMWCNT 4201 4520 1686 1310 1043 988

Vol 1 Pag43

PPG 4023 4451 1680 1350 930 909

PPCB 4302 4553 1692 1256 902 888

Neat PP 349 2886

PPMWCNT 430 8616

PPG 421 9803

PPCB 442 9130

Vol 1 Pag44

Vol 1 Pag45

Vol 1 Pag46

Introduction

Experimental

Vol 1 Pag47

1500 1350 1200 1050 900 750 6000

102030405060708090

100110120

Wavenumber (cm-1)

9511233-990

20 30 40 50 60 70

LaPO4 700 degC

LaPO4 600 degC

LaPO4 500 degC

LaPO4 400 degC

2(deg)

) (103

22) (1

23) (4

0 1000 2000 3000 4000 50000

40LaPO4

Dz = 2300 nm PDI = 12

Diameter (nm)

Vol 1 Pag48

400 450 500 550 600 650 7000

) LaPO4

2000 1800 1600 1400 1200 1000 800

C-O-CCH3

Wavelength (cm-1)

Commercial PMMA CH

C-O group

2000 1800 1600 1400 1200 1000 800

Synthesized PMMA CH

CH3CH3CH

Wavenumber (cm-1)

C-O group

200 300 400 500 600 700

Wavelength (nm)

Commercial PMMA

200 300 400 500 600 700

Wavelength (nm)

LaPO4 content (wt)

0 65 108 01 86 110 05 98 112 1 99 115

Vol 1 Pag49

Conclusions

References

Acknowledgements

Vol 1 Pag50

PETCHITOSAN BLENDS

ATDEq (1)

Vol 1 Pag51

2000 1750 1500 1250 1000 750

PETPLA 8515

C-OCH2

1768-1670

R-PETPLA 955

PET signalsC=O PLA

Wavenumber (cm-1)

3000 2500 2000 1500 1000

PETchitosan 991

PETchitosan 97525

PETchitosan 955

R-PETchitosan 991

R-PETchitosan 97525

Wavenumber (cm-1)

R-PETchitosan 955

C=O PET

2000 1800 1600 1400 1200 1000 800

PET-PLA 955

PET-PLA 8515

PET-PLA 9010

C-O1700 1747 C=O(a)

Wavenumber (cm-1)

2000 1800 1600 1400 1200 1000 800

R-PETPLA 8515

R-PETPLA 9010

R-PETPLA 955

Wavenumber (cm-1)2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715 1700

C=O(c)CH2

2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715

1700C=O(c) CH2

PETchitosan 955

Vol 1 Pag52

00 10x10-3 20x10-3 30x10-3 40x10-3

107 years103 years

76 years

91 years

58 years

54 years

143 years93 years

60 years

56 years

55 years

PETPLA 8515

PETPLA9010

PETPLA 955

R-PETPLA 8515

R-PETPLA9010

R-PETPLA 955

PETchitosan 955

PETchitosan 97525

PETchitosan 991

R-PETchitosan 955

R-PETchitosan 97525

R-PETchitosan 991

45 years

Vol 1 Pag53

PET 126 243 201 248 170 R-PET 245 205 227 245 156 PLA 161 126 150 120

R-PETChitosan 955 250 208 240 -

Vol 1 Pag54

ABSTRACT

INTRODUCTION

Vol 1 Pag55

Vol 1 Pag56

carbohydrate

CONCLUSIONS

AKNOWLEDGEMENTS

Vol 1 Pag57

Vol 1 Pag58

Vol 1 Pag59

Vol 1 Pag60

Vol 1 Pag61

References

Vol 1 Pag62

Vol 1 Pag63

Vol 1 Pag64

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

24 h NCC 1wt

01 52 00 220 012 0001

MCC 2wt

01 51 01 255 013 0015

MCC 5wt

01 51 01 360 023 0010

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

(mgAgP) DS

NCC 2wt

0217 39 09 0 005 0021

MCC 2wt

0213 23 01 5 013 0014

24 h MCC 4wt

0208 19 01 22 015 0005

MCC 6wt

0220 19 01 23 014 0010

MCC 8wt

0210 20 04 22 015 0004

Vol 1 Pag65

References

Vol 1 Pag66

ABSTRACT

INTRODUCTION

Vol 1 Pag67

Vol 1 Pag68

Vol 1 Pag69

Vol 1 Pag70

Vol 1 Pag71

catalyst

INTRODUCTION

Vol 1 Pag72

Vol 1 Pag73

r = 22 r = 09 r = 05

Yield () 71 100 100

E-factor (gg) 143 226 408

Vol 1 Pag74

Vol 1 Pag75

yarelirojasgmailcom

Abstract

Introduction

Vol 1 Pag76

Results

Vol 1 Pag77

Vol 1 Pag78

System Reactiontime

Yield()

βCD-CL-MW 45 min 57 316 873

Conclusions

References

Acknowledgment

Vol 1 Pag79

N NBF2

(Not isolated)

NH H O

R1234+

Conventional Method

2 eq 1 eq

Mechanochemical

Vol 1 Pag80

Reaction Steps

- No solvents

solvent

-Reaction time 1min

Reaction time 3h

and purity

Vol 1 Pag81

Vol 1 Pag82

Vol 1 Pag83

Vol 1 Pag84

1inc p

inc m inc pst

minus = minus

34174 25 (2)097411

minus = = minus

(grcm3)

Inclusion prototype

radius microm

0974 1 34 74 50-100

4 49 250125 500 5 612 219211 730 6 734 110147 500

Vol 1 Pag85

Vol 1 Pag86

REFERENCES

Vol 1 Pag87

Vol 1 Pag88

trfloresunammx

Vol 1 Pag89

100 200 300 400 500 600 700 800 900

Temperature (degC)

βminusLi5AlO4

chemisorption

] = -kt (2)

Vol 1 Pag90

0 20 40 60 80 100 120 140 160 180100

550 degC

650 degC

600 degC

Time (min)

700 degC

400 450 500 550 600 650 700

0025 βminusLi5AlO4

ln [Li5AlO4] =-k t

k (s-1

Temperature (degC)

for short times

13 = kD

Vol 1 Pag91

400 450 500 550 600 650 700

20x10-6

40x10-6

60x10-6

80x10-6

10x10-5

βminusLi5AlO4

kD t = 1-(1-α)13

k D (s-1

Temperature (degC)

Vol 1 Pag92

Vol 1 Pag93

Vol 1 Pag94

Vol 1 Pag95

Vol 1 Pag96

Scheme 1

Ru N OClN

Vol 1 Pag97

N ORR =

fluorene

Scheme 2

Vol 1 Pag98

Vol 1 Pag99

Perspectives

120590120590 =161205871205872119891119891(120583120583119890119890119890119890 minus 120583120583119892119892119892119892)2

References

4641-4678

Vol 1 Pag100

Abstract

Vol 1 Pag101

Free surface

Contact wheel

TiC α-Al

(a) (b) (c)

Vol 1 Pag102

(a) (b)

Vol 1 Pag103

Vol 1 Pag104

Vol 1 Pag105

m m 5 nm5 nm

5 10 20 30 40 50 600

Diameter (nm)

2 nm2 nm

a) (204)

5 nm5 nm

105deg25deg

250 300 350 400 450 500 550Ab

Wavelength (nm)

roots stems leaves

Vol 1 Pag106

DISCUSSION

CONCLUSION

Vol 1 Pag107

References

Vol 1 Pag108

ACTIVATION

Vol 1 Pag109

Vol 1 Pag110

Conclusion

Vol 1 Pag111

Vol 1 Pag112

Vol 1 Pag113

Vol 1 Pag114

Vol 1 Pag115

Vol 1 Pag116

Vol 1 Pag117

Vol 1 Pag118

Vol 1 Pag119

Introduction

Vol 1 Pag120

N NTaBu Bu

t-BuNHLi

TaBu Nt-But-BuN

N NBu Bu

supernatant

months

excess

Vol 1 Pag121

Vol 1 Pag122

TaBu Nt-But-BuN

N NBu Bu

N NTaBu Bu

355360365370375380385390395400405410415420425430435440445450455460465470475480485490495500f1 (ppm)

14 days 120 degC

4 days 160 degC

13 days 160 degC

reported[3c 16b 17]

Vol 1 Pag123

LiNR2N N

N NTaBu Bu

Nt-But-BuN

N TaBu

Nt-But-BuN

TaBu Nt-But-BuN

- HNR2

TaBu Nt-But-BuN

- R2N-

Vol 1 Pag124

Vol 1 Pag125

Vol 1 Pag126

Vol 1 Pag127

RefluxNa2SO4

48 h OHaHbO

F3C CF3

OHaHbO

F3C CF3

PdL1 PdL2

PdL3 PdL4

Vol 1 Pag128

Vol 1 Pag129

Vol 1 Pag130

References

Vol 1 Pag131

Vol 1 Pag132

Surfactant AA ()

Conversion ()

Z Potential (mV)

DP DLS (nm)

P(S-DVB-AA)

Vol 1 Pag133

(degC) Cristalinity

() Đ Mw (gmol)

Vol 1 Pag134

Vol 1 Pag135

Vol 1 Pag136

Vol 1 Pag137

ISSN 2448-590X

Plenary Lecture

Vol 1 Pag6

2bc gt95 98 ee

2ec gt95 99 ee

2cc gt95 98 ee

2gc gt95 99 ee

2ac gt95 99 ee

2oc gt95 94 eea

2jc gt95 94 ee

nC6H13

OHnC11H23

2kc gt95 95 ee

2lc gt95 99 ee

2mc gt95 99 ee

2ic 56 73 ee

2dc gt95 93 ee

2hc gt95 99 ee

2fc gt95 99 ee

2nc gt95 99 ee

Vol 1 Pag7

LigFe-OR

[LigFe-H]

FeLigH

LigFe-OAc

References

Vol 1 Pag8

Vol 1 Pag9

Casting

Vol 1 Pag10

Vol 1 Pag11

Vol 1 Pag12

Vol 1 Pag13

INTRODUCTION

EXPERIMENTAL

00E+00

20E+08

40E+08

60E+08

80E+08

10E+09

12E+09

050100150200

204 degC ECP

249 degC ECP

Vol 1 Pag14

AGTNCSUbench

400 degCAGTNCSU

00100200300400500600700800900

-50E+07

00E+00

50E+07

10E+08

15E+08

20E+08

25E+08

30E+08

35E+08

456585105

204 degC ECP

249 degC ECP

Vol 1 Pag15

-500E+06000E+00500E+06100E+07150E+07200E+07250E+07300E+07350E+07

0102030405060

204 degC ECP

249 degC ECP

-500E+07

000E+00

500E+07

100E+08

150E+08

95115135155175

204 degC ECP

249 degC ECP

Vol 1 Pag16

y = -43642x + 11255Rsup2 = 0986

00 05 10 15 20 25 30

(H+O)C

Vol 1 Pag17

CONCLUSIONS

REFERENCES [1]

Vol 1 Pag18

Vol 1 Pag19

Vol 1 Pag20

References

[2] Prog Polym Sci 2010 35 1350

[3] Polymer 2015 55 642

[5] Polymer 2002 43 2279

Vol 1 Pag21

Vol 1 Pag22

Introduction

1 0 60 15 2 0 30 30 3 0 0 15 4 1 0 30 5 1 30 15 6 1 60 30 7 2 30 0 8 1 30 15 9 1 60 0

Vol 1 Pag23

10 1 30 15 11 2 60 15 12 2 0 15 13 1 30 15 14 2 30 30 15 1 0 0 16 0 30 0 17 1 30 15

Vol 1 Pag24

SUMMARY

INTRODUCTION

Vol 1 Pag25

METHODOLOGY

RESULTS

Vol 1 Pag26

Vol 1 Pag27

CONCLUSIONS

ACKNOWLEDGEMENTS

REFERENCES

Vol 1 Pag28

Introduction

Experimental

2O(12)Clay 5 wt-

Vol 1 Pag29

Time (min)

PAAcH2O (11)Clay

PAAcH2O (12)Clay

PAAcH2O (21)

PAAcH2O (11)

PAAcH2O (12)

0 0 0 0 0 0 000 5 5414 3424 6115 4210 4723 5000

10 6934 6373 7806 5365 6902 6758 20 10276 11288 12590 7477 8642 9848 30 12320 14644 15036 8831 10612 12727 60 22707 21627 24532 12629 15870 19227 90 30580 26746 28201 15631 20497 24576

120 34834 32203 32014 18619 24704 30076 180 41796 38610 39460 23147 31453 39318 240 42652 44271 46223 25976 35698 47364 360 43867 51627 51475 30066 42620 60712 480 44116 56610 54748 32390 46654 72121

1440 45829 69017 63993 36521 55449 124091 2880 46298 71627 66367 37397 58107 158485

Vol 1 Pag30

Vol 1 Pag31

Conclusions

Vol 1 Pag32

Nevaacuterez1

I Introduction

Vol 1 Pag33

II Metodology

Membrane synthesis

III Results

Vol 1 Pag34

IV Conclusion

Vol 1 Pag35

V References

Vol 1 Pag36

Vol 1 Pag37

0 200 400 600 800 1000

Exposure time (hr)

HDPECu

Vol 1 Pag38

0 200 400 600 800 1000

Exposure time (hr)

HDPEMWCNTs

Vol 1 Pag39

0 200 400 600 800 1000

Exposure time (hr)

0 200 400 600 800 1000

Exposure time (hr)

Vol 1 Pag40

References

[1] Comp Sci Tech 2007 67 3071

[2] J Appl Polym Sci 2004 91 2781

[3] Mat Charac 2013 84 58

[4] Comp Part B Eng 2013 55 407

Vol 1 Pag41

Vol 1 Pag42

Neat PP 3735 4376 1684 1109 941 973

PPMWCNT 4201 4520 1686 1310 1043 988

Vol 1 Pag43

PPG 4023 4451 1680 1350 930 909

PPCB 4302 4553 1692 1256 902 888

Neat PP 349 2886

PPMWCNT 430 8616

PPG 421 9803

PPCB 442 9130

Vol 1 Pag44

Vol 1 Pag45

Vol 1 Pag46

Introduction

Experimental

Vol 1 Pag47

1500 1350 1200 1050 900 750 6000

102030405060708090

100110120

Wavenumber (cm-1)

9511233-990

20 30 40 50 60 70

LaPO4 700 degC

LaPO4 600 degC

LaPO4 500 degC

LaPO4 400 degC

2(deg)

) (103

22) (1

23) (4

0 1000 2000 3000 4000 50000

40LaPO4

Dz = 2300 nm PDI = 12

Diameter (nm)

Vol 1 Pag48

400 450 500 550 600 650 7000

) LaPO4

2000 1800 1600 1400 1200 1000 800

C-O-CCH3

Wavelength (cm-1)

Commercial PMMA CH

C-O group

2000 1800 1600 1400 1200 1000 800

Synthesized PMMA CH

CH3CH3CH

Wavenumber (cm-1)

C-O group

200 300 400 500 600 700

Wavelength (nm)

Commercial PMMA

200 300 400 500 600 700

Wavelength (nm)

LaPO4 content (wt)

0 65 108 01 86 110 05 98 112 1 99 115

Vol 1 Pag49

Conclusions

References

Acknowledgements

Vol 1 Pag50

PETCHITOSAN BLENDS

ATDEq (1)

Vol 1 Pag51

2000 1750 1500 1250 1000 750

PETPLA 8515

C-OCH2

1768-1670

R-PETPLA 955

PET signalsC=O PLA

Wavenumber (cm-1)

3000 2500 2000 1500 1000

PETchitosan 991

PETchitosan 97525

PETchitosan 955

R-PETchitosan 991

R-PETchitosan 97525

Wavenumber (cm-1)

R-PETchitosan 955

C=O PET

2000 1800 1600 1400 1200 1000 800

PET-PLA 955

PET-PLA 8515

PET-PLA 9010

C-O1700 1747 C=O(a)

Wavenumber (cm-1)

2000 1800 1600 1400 1200 1000 800

R-PETPLA 8515

R-PETPLA 9010

R-PETPLA 955

Wavenumber (cm-1)2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715 1700

C=O(c)CH2

2000 1800 1600 1400 1200 1000 800

PETchitosan 97525

PETchitosan 991

C=O(a)

Wavenumber (cm-1)

17461715

1700C=O(c) CH2

PETchitosan 955

Vol 1 Pag52

00 10x10-3 20x10-3 30x10-3 40x10-3

107 years103 years

76 years

91 years

58 years

54 years

143 years93 years

60 years

56 years

55 years

PETPLA 8515

PETPLA9010

PETPLA 955

R-PETPLA 8515

R-PETPLA9010

R-PETPLA 955

PETchitosan 955

PETchitosan 97525

PETchitosan 991

R-PETchitosan 955

R-PETchitosan 97525

R-PETchitosan 991

45 years

Vol 1 Pag53

PET 126 243 201 248 170 R-PET 245 205 227 245 156 PLA 161 126 150 120

R-PETChitosan 955 250 208 240 -

Vol 1 Pag54

ABSTRACT

INTRODUCTION

Vol 1 Pag55

Vol 1 Pag56

carbohydrate

CONCLUSIONS

AKNOWLEDGEMENTS

Vol 1 Pag57

Vol 1 Pag58

Vol 1 Pag59

Vol 1 Pag60

Vol 1 Pag61

References

Vol 1 Pag62

Vol 1 Pag63

Vol 1 Pag64

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

24 h NCC 1wt

01 52 00 220 012 0001

MCC 2wt

01 51 01 255 013 0015

MCC 5wt

01 51 01 360 023 0010

Sample Weight (g)

Prom Cf (mgL) DS

Removal Percentage

(mgAgP) DS

NCC 2wt

0217 39 09 0 005 0021

MCC 2wt

0213 23 01 5 013 0014

24 h MCC 4wt

0208 19 01 22 015 0005

MCC 6wt

0220 19 01 23 014 0010

MCC 8wt

0210 20 04 22 015 0004

Vol 1 Pag65

References

Vol 1 Pag66

ABSTRACT

INTRODUCTION

Vol 1 Pag67

Vol 1 Pag68

Vol 1 Pag69

Vol 1 Pag70

Vol 1 Pag71

catalyst

INTRODUCTION

Vol 1 Pag72

Vol 1 Pag73

r = 22 r = 09 r = 05

Yield () 71 100 100

E-factor (gg) 143 226 408

Vol 1 Pag74

Vol 1 Pag75

yarelirojasgmailcom

Abstract

Introduction

Vol 1 Pag76

Results

Vol 1 Pag77

Vol 1 Pag78

System Reactiontime

Yield()

βCD-CL-MW 45 min 57 316 873

Conclusions

References

Acknowledgment

Vol 1 Pag79

N NBF2

(Not isolated)

NH H O

R1234+

Conventional Method

2 eq 1 eq

Mechanochemical

Vol 1 Pag80

Reaction Steps

- No solvents

solvent

-Reaction time 1min

Reaction time 3h

and purity

Vol 1 Pag81

Vol 1 Pag82

Vol 1 Pag83

Vol 1 Pag84

1inc p

inc m inc pst

minus = minus

34174 25 (2)097411

minus = = minus

(grcm3)

Inclusion prototype

radius microm

0974 1 34 74 50-100

4 49 250125 500 5 612 219211 730 6 734 110147 500

Vol 1 Pag85

Vol 1 Pag86

REFERENCES

Vol 1 Pag87

Vol 1 Pag88

trfloresunammx

Vol 1 Pag89

100 200 300 400 500 600 700 800 900

Temperature (degC)

βminusLi5AlO4

chemisorption

] = -kt (2)

Vol 1 Pag90

0 20 40 60 80 100 120 140 160 180100

550 degC

650 degC

600 degC

Time (min)

700 degC

400 450 500 550 600 650 700

0025 βminusLi5AlO4

ln [Li5AlO4] =-k t

k (s-1

Temperature (degC)

for short times

13 = kD

Vol 1 Pag91

400 450 500 550 600 650 700

20x10-6

40x10-6

60x10-6

80x10-6

10x10-5

βminusLi5AlO4

kD t = 1-(1-α)13

k D (s-1

Temperature (degC)

Vol 1 Pag92

Vol 1 Pag93

Vol 1 Pag94

Vol 1 Pag95

Vol 1 Pag96

Scheme 1

Ru N OClN

Vol 1 Pag97

N ORR =

fluorene

Scheme 2

Vol 1 Pag98

Vol 1 Pag99

Perspectives

120590120590 =161205871205872119891119891(120583120583119890119890119890119890 minus 120583120583119892119892119892119892)2

References

4641-4678

Vol 1 Pag100

Abstract

Vol 1 Pag101

Free surface

Contact wheel

TiC α-Al

(a) (b) (c)

Vol 1 Pag102

(a) (b)

Vol 1 Pag103

Vol 1 Pag104

Vol 1 Pag105

m m 5 nm5 nm

5 10 20 30 40 50 600

Diameter (nm)

2 nm2 nm

a) (204)

5 nm5 nm

105deg25deg

250 300 350 400 450 500 550Ab

Wavelength (nm)

roots stems leaves

Vol 1 Pag106

DISCUSSION

CONCLUSION

Vol 1 Pag107

References

Vol 1 Pag108

ACTIVATION

Vol 1 Pag109

Vol 1 Pag110

Conclusion

Vol 1 Pag111

Vol 1 Pag112

Vol 1 Pag113

Vol 1 Pag114

Vol 1 Pag115

Vol 1 Pag116

Vol 1 Pag117

Vol 1 Pag118

Vol 1 Pag119

Introduction

Vol 1 Pag120

N NTaBu Bu

t-BuNHLi

TaBu Nt-But-BuN

N NBu Bu

supernatant

months

excess

Vol 1 Pag121

Vol 1 Pag122

TaBu Nt-But-BuN

N NBu Bu

N NTaBu Bu

355360365370375380385390395400405410415420425430435440445450455460465470475480485490495500f1 (ppm)

14 days 120 degC

4 days 160 degC

13 days 160 degC

reported[3c 16b 17]

Vol 1 Pag123

LiNR2N N

N NTaBu Bu

Nt-But-BuN

N TaBu

Nt-But-BuN

TaBu Nt-But-BuN

- HNR2

TaBu Nt-But-BuN

- R2N-

Vol 1 Pag124

Vol 1 Pag125

Vol 1 Pag126

Vol 1 Pag127

RefluxNa2SO4

48 h OHaHbO

F3C CF3

OHaHbO

F3C CF3

PdL1 PdL2

PdL3 PdL4

Vol 1 Pag128

Vol 1 Pag129

Vol 1 Pag130

References

Vol 1 Pag131

Vol 1 Pag132

Surfactant AA ()

Conversion ()

Z Potential (mV)

DP DLS (nm)

P(S-DVB-AA)

Vol 1 Pag133

(degC) Cristalinity

() Đ Mw (gmol)

Vol 1 Pag134

Vol 1 Pag135

Vol 1 Pag136

Vol 1 Pag137

ISSN 2448-590X

Plenary Lecture

Documents

Polymat...in the chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi reaction of aldehydes gave the corresponding alcohols with a maximum enantioselectivity of 93 %. 10 In a systematic