Synthesis and Characterization of Mass

production of high quality Reduced

Graphene Sheets via a Chemical Method M.Muthumari *1, P.Thondaiman*2

*Dept. of Nano-science Technology, Anna University Regional Centre

Coimbatore, India.

1muthumarimv@gmail.com

2p.thondaiman@gmail.com

Abstract: Graphene is a two-dimensional crystal of carbon

atoms arranged in a honeycomb lattice. It is a zero band gap

semimetal with very unique physical and chemical

properties which make it useful for many applications such

as ultra-high-speed field-effect transistors, p-n junction

diodes, Tera-hertz oscillators, and low-noise electronic,

NEMS and sensors. When the high quality mass production

of this nanomaterial is still a big challenge, we developed a

process which will be an important step to achieve this goal.

In this study, a new chemical process is used and robust

solution process has been developed to obtain high quality

Graphene sheets in aqueous solution and these sheets were

characterized by UV-Vis, FTIR, Scanning Electron

Microscopy, X-Ray Diffraction were investigated to

characterize and examine the quality of this product. This

project demonstrates a mass production of pure Graphene

powder via our modified hummers method followed by

different dispersion and purification process.

Keywords: Reduced Graphene Oxide, Graphene sheets,

Hummers.

I. INTRODUCTION

Graphene is the name given to a flat monolayer

of carbon atoms tightly packed into a two- dimensional

(2D) honeycomb lattice, and is a basic building block for

graphitic materials of all other dimensionalities.

Graphene is a material that has experienced a tremendous

increase in interest in the last few years. This is evident

considering that the numbers of rapports have increased

from around 500 in 2006 to 3000 in 2010. One of the

reasons why there is such a big interest in the

development of coal based semi- conductors such as

Graphene and carbon nano-tubes is the possibility to use

them as a replacement for rare earth metals.

Rare earth metals are, despite the name,

moderately abundant in the earth’s core although most of

them are not concentrated enough to make mining

economically viable. The demand for rare earth metals is

estimated at 134, 000 tons per year, and a global

production of 124, 000 tons the production is covered by

above-ground stocks or inventories. World-wide demand

is projected to rise to 180, 000 tons annually by 2012,

while it is unlikely that new mine output will close the

gap in short term. By 2014 global demand for rare earth

metals may exceed 200, 000 tons per year. As mentioned

before Graphene seems to have many fields of

application, these ranges from electronics to optics and

medical science. For example Graphene can be used to

create good capacitor when either combined with a

polymer as a composite or used in its pure form.

Graphene has also been used to construct sensitive

sensors that can detect very low traces of a specific

prostrate antigen. General properties has been reported

that Graphene has very high stiffness, breaking strength

and very high thermal conductivity, measured between

4.84-5.30 kW m-1 K-1. Except from the other more

common properties Graphene also has a quantum Hall

effect in room temperature.

II. MATERIAL AND METHODS

The following chemicals were purchased in AR

grade. Graphite flakes (natural, -10 mesh, 99.9%) and

sodium nitrate (NaNO3) were purchased from NICE,

Potassium permanganate (KMnO4) was purchased from

RFCL limited and H2SO4 (95-98 w %), Hydrogen

peroxide (H2O2), Hydrazine Hydrate (N2H5OH)

purchased from LOBACHEMIE. Ammonia solution was

purchased from MERCK.

A. Preparation of Graphene Oxide (GO)

First, sulfuric acid was mixed with phosphoric

acid in a 9:1 ratio (90 ml H2SO4, 10 ml H3PO4), the

solution was then heated to 50 degrees Celsius. Potassium

permanganate was added (4,5g) and then the solution was

left to be stirred for approximately 10 minutes, this to

ensure that all of the KMnO4 was dissolved. A sample

was taken before graphite was added and about two

minutes into the reaction. In the beginning the samples

were taken with a quite small interval (~30min) to

compare with previous work regarding the oxidation. The

intervals were later increased to monitor a possible

change in concentration after the alleged reaction time

had passed. Samples was weighed and diluted to 1/1000

in weight percentage with double distilled water and

cooled in to 4˚C to avoid further reaction.

Change being defined as any changes either

visible by the naked eye or measured with an instrument,

i.e. change in viscosity, color or the concentration of a

selected substance. As the reaction progressed the

reaction mixture turned from a brown/black color to a

pale grey color. At the same time the viscosity of the

solution increased, in order to sustain the stirring the

power had to be increased. The increase in viscosity and

other visual changes were observed long after 12 hours

had passed. In a failed batch the water that was used in

the heating bath was boiled of. This resulted in the

mixture turning to a pitch black color, the density and

other properties being somewhat unchanged. In the later

washing step of the batch most turned out to be to large

particles to pass the filter.

When the reaction was deemed to be finished the

reaction was stopped by adding (0-7.5) ml H2O2 which

had been mixed with ~100ml of ice. As the reaction

between the acids and water produce a significant amount

of heat the procedure was also performed in a cooling

bath. This experiment is relatively safe, and the danger of

explosion is reduced significantly, in contrast to the

normal route of after 3 days of oxidation. The GO

chemical oxidation of graphite. Furthermore, the mixing

and washing steps are simple and straightforward,

yielding an almost 100% conversion of large-area GO.

B. Preparation Reduced Graphene Oxide (rGO)

The obtained Graphene-oxide was once again

dissolved in water. This was performed by adding GO in

water to a concentration of 1 mg/ml in a small sample

vessel made out of glass, and then using a sonication

device to disperse the dried GO. As it turned out the dried

GO was quite hard to dissolve after it had been dried into

solid form. By subsequently using sonication and then

letting the material dissolve for at least 10 minutes almost

all of the GO could finally be solved into the water. It

should be noted that there always was some GO that

didn’t dissolve into the liquid which would appear as

minute solid particles into the solution.

Later on the solution was transferred to the

reaction vessel and diluted to a concentration of

0,1mg/ml. Hydrazine Hydrate was added to the solution

so that it corresponded to (0-1) wt % and then the reaction

vessel was mounted in a heat bath at a temperature of

95°C. The solution was left to be re-boiled in the heat bath

for 24 hours, during this time the solution changes color

from brown to black. After 24 hours Ammonium solution

(25µ) was then added to the solution; this accelerates the

reduction process and drives it forward. In the beginning

of the experiments there was an excessive agglomeration

of rGO particles when ammonia solution was added

resulting in a loss of some GO. As there was not very

much material gained from the oxidation of natural

graphite the concentration had to be lowered to conserve

material until the problem was solved. The reactions were

carried out in an excessive amount of time compared to

reactions mentioned in the previous work which was

around 3 hours after ammonia was added. In general the

entire reaction time was ~72 hours but as with the

oxidation time the reactions were judged individually.

III. RESULT AND DISCUSSION

In this work, the large scale and the high purity of

Graphene sheets from our synthesized powder were

examined by different morphological and structural

techniques.

A. UV-VIS Analysis of Graphite & GO

From Fig.1 UV-VIS spectra of GO exhibits a maximum

absorption peak at about 229nm, corresponding to π-π*

transition of aromatic C-C bonds. The absorption peak for

reduced GO had red shifted to 262 nm. This phenomenon

of red shift has been used as a monitoring tool for the

reduction of GO.

Fig.1 UV-VIS spectra analysis of Graphite and Graphene oxide

B. XRD Analysis of Reduced Graphene Oxide:

Graphite contains a very distinct and sharp (002) peak

which transforms into a broad shaped peak in graphite

oxide due to addition of the functional groups. Graphite

loses its crystalinity and converts into a semi-crystalline

and hydrophilic structure on oxidation.

Fig.2 XRD pattern of Reduced Graphene Oxide

The first stage where the peak around 27 degrees appears

and the peak at around 10 degrees appear (2θ) is visible

for all the samples of oxidized graphite. The differences

between them are so small that it suggests that the

oxidation has been successful in all cases and only small

differences in this part of the process exist.

C. FTIR Analysis:

Fig.3 FTIR analysis of Graphene oxide

From Fig.3 the presence of different type of

oxygen functionalities in Graphene oxide was confirmed

at 3400 cm-1 (O-H stretching vibrations), at 1720 cm-1

(stretching vibrations from C=O), at 1600 cm-1 (skeletal

vibrations from oxidized graphitic domains), at 1220 cm-

1 (C-OH stretching vibrations), and at 1060 cm-1 (C-O

stretching vibrations).

Fig.4 FTIR analysis of Reduced Graphene oxide

From Fig.4 FTIR peak of reduced Graphene

which revealed by the circle presents that O-H stretching

vibrations observed around at 2500 cm-1 was

significantly reduced due to de oxygenation. However,

stretching vibrations from C=O at 1720 cm-1 were still

observed and C-O stretching vibrations at 1060 cm-1

became sharper, which were caused by remaining

carboxyl groups even after hydrazine reduction

D. SEM Analysis:

From Fig.5 shows the morphology and structure

of as prepared rGO sheets were first investigated via

SEM. Cross-sectional SEM image reveal the sheet type

architecture.

Fig.5 SEM analysis of Reduced GO

IV. CONCLUSION

In conclusion, reduced Graphene sheets were

successfully synthesized by modified hummers method

followed by chemical reduction via hydrazine hydrate

and ammonia hydroxide. The synthesized reduced

Graphene oxide was coated on the cellulose acetate

membrane for desalination. The prepared rGO was

analyzed by XRD, SEM, UV, FTIR analysis. We report a

highly this method for the preparation of scalable large-

area rGO. The method was carried out at room

temperature with the highest conversion possible (100%

conversion of graphite flakes to rGO) to produce large-

area rGO without ultrasonication. Here, we have

identified key factors contributing to the large area of

rGO formed, which are complete oxidation of graphite

through a high degree of oxidation and the need to carry

out the reaction at room temperature. Our method of

synthesizing rGO will infinitely increase the rate of rGO

production for numerous investigations, which might

appeal to biologists, chemists, physicists, and materials

scientists.

REFERENCE

[1] Geim, A.K. and Novoselov, K.S. (2007) The Rise of Grapheme.

Nature Materials, 6, 183-191.

[2] Morozov, S.V., Novoselov, K.S., Katsnelson, M.I., Schedin, F.,

Elias, D.C., Jaszczak, J.A. and Geim, A.K. (2008) Physical Review

Letters, 100, Article ID: 016602.

[3] Hummers, W.S and Offeman Jr., R.E. (1958) Journal of American

Chemical Society, 80, 1339.

[4] Caterina, S., Ather, M. and Erik, D. (2010) Production, Properties

and Potential of Graphene. Carbon, 48, 2127-2150.

[5] Ju H-M, Huh SH, Choi S-H, Lee H-L. Structures of thermally and

chemically reduced graphene. Mater Lett. 2010;64:357–360.

[6] Marcano DC, Kosynkin DV, Berlin JM, et al. Improved synthesis of

graphene oxide. ACS Nano. 2010;4:4806–4814.

[7] Geng Y, Wang SJ, Kim J-K. Preparation of graphite nanoplatelets

and graphene sheets. J Colloid Interface Sci. 2009;336:592–598.

[8] Park S, Mohanty N, Suk JW, et al. Biocompatible, robust free-

standing paper composed of a TWEEN/graphene composite. Adv

Mater.2010;22: 1736–1740.

[9] Dikin DA, Stankovich S, Zimney EJ, et al. Preparation and

characterization of graphene oxide paper. Nature. 2007;448:457–460.

[10] Geng Y, Wang SJ, Kim J-K. Preparation of graphite nanoplatelets

and graphene sheets. J Colloid Interface Sci. 2009;336:592–598.

[11] Q. Liu, J. Shi, M. Cheng, G. Li, D. Cao, G. Jiang : Preparation of

graphene-encapsulated magnetic microspheres for protein/peptide

enrichment and MALDI-TOF MS analysis : Chemical Communications

48 [1874-1876] (2012).

[12] H. Suna, Y. Yangb, Q. Huang: Preparation and Structural

Variation of Graphite Oxide and Graphene Oxide: Integrated

Ferroelectrics 128163-170] (2011).

[13] Z. Xu, C. Gao: Graphene chiral liquid crystals and macroscopic

assembled fibers: Nature Communications 571 (2011).

[14] R.S. Pantelic, J.W. Suk, C.W. Magnuson, J.C. Meyer, P.

Wachsmuth, U. Kaiser, R.S. Ruoff,H. Stahlberg : Graphene: Substrate

preparation and introduction : Journal of Structural Biology 74 [234-

238] (2011).

[15] S. Mao, H. Pu, J. Chen: Graphene oxide and its reduction: modeling

and experimental progress: RSC Adv. 2 [2643-2662] (2012).

[16] B.C. Brodie: Sur le poids atomique du graphite: Ann. Chim. Phys.

59 [466–472] (1860).

[17] J.H. Chen, C. Jang, S. Xiao, M. Ishigami, M.S. Fuhrer : Intrinsic

and extrinsic performance limits of graphene devices on SiO2 : Nature

Nanotechnology 3 [206 -209] (2008).

[18] S. Stankovich, D.A. Dikin, R.D. Piner, K.A. Kohlhaas, A.

Kleinhamme, Y. Jia, Y. Wu, S.T. Nguyen and R.S. Ruoff: Synthesis of

graphene based nanosheets via chemical reduction of exfoliated

graphite oxide: Carbon 45 [1558–1565] (2007).

[19] A. Kaniyoor, T.T. Baby, S. Ramaprabhu: Graphene synthesis via

hydrogen induced low temperature exfoliation of graphitic oxide:

Journal of Materials Chemistry 20 [8467-8469] (2010).

[20] D.C. Marcano et al: Improved synthesis of graphene oxide: Journal

of the American Chemical Society 4 [4806-4814] (2010).

[21] Y. Hernandez, M. Lotya, V. Nicolosi, F.M.Blighe, S. De, G.

Duesberg, J.N.Coleman: Liquid phase production of graphene by

exfoliation of graphite in surfactant/water solutions: Journal of

American Chemical Society 131 [3611-3620] (2009).

[22] T. Chen, B. Zeng, J.L. Liu, J.H. Dong, X.Q. Liu, Z. Wu, X.Z.

Yang, Z.M. Li : High throughput exfoliation of graphene oxide from

expanded graphite with assistance of strong oxidant in modified

Hummers method : Journal of Physics : Conference Series 188 (2009)

[23] D.D.L Chung: Review of exfoliation of graphite: Journal of

Materials Science 22 [4190-4198] (1987).

[24] F. Ali, N. Agarwal, P.K. Nayak, R. Das and N. Periasamy:

Chemical route to the formation of graphene: Current Science 97 [683-

685] (2009).

National Conference on Research Advances in Communication, Computation, Electrical Science and Structures (NCRACCESS-2015)

ISSN: 2394 - 2703 www.internationaljournalssrg.org Page 5

BNNT/Al2O3 composites using Polymer Nanocomposites for Enhancing

Aerospace Applications M.pandiyarajan

1,*, E.Muthusankar

2*

* Dept. of Nano Science and Technology, Anna University Regional Centre,

Coimbatore, 641 047, India

ABSTRACT

Polymer matrix Nanocomposites have been proving its

capability in the aerospace industry owing to enhanced

strength to weight ratio and its flexibility. To improve the

performance of structural composites, materials with

different morphologies are being explored by incorporating

with different materials. Boron Nitride Nano tubes (BNNT)

with Nano sized Alumina (Al2O3) are composited by solvent

casting route to improve the thermal as well as mechanical

property. Nano sized BNNT and Alumina (47nm) were

prepared via chemical and sol-gel synthesis respectively.

Also, Radiation shielding property is geared up for the

Nanocomposites are going to done by impregnating the

materials with PANI (poly aniline) matrix. The equipped

Nanocomposites are characterized by XRD, SEM, TGA and

FTIR. Then the radiation shielding property is tested by

vector network analysis.

Keywords: Boronnitridenanotubes (BNNT), Alumina,

PANI, polmer Nanocomposites

1.INTRODUCTION

Nanotechnology is science, engineering,

and technology conducted at the nanoscale level to

control and manipulation of matter at nanometre

dimensions. Nanocomposite is a multiphase solid

material where one of the phases has one, two or three

dimensions of less than 100 nanometres (nm), or

structures having nano-scale repeat distances between

the different phases that make up the material.

Mechanical strengthening or restricting matrix

dislocation movement. In mechanical terms,

nanocomposites differ from conventional composite

materials due to the exceptionally high surface to

volume ratio of the reinforcing phase and/or its

exceptionally high aspect ratio.

1. a.Ceramic-matrix Nanocomposites

In this group of composites the main part

of thevolume is occupied by a ceramic, i.e. a

chemical compound from the group of oxides,

nitrides, borides, silicides etc... Higher

mechanical properties and tungsten disulfide

nanotubes are better reinforcing agents than

carbon nanotubes.

1. b.Metal-matrix nanocomposites

Metal matrix Nanocomposites can also be

defined as reinforced metal matrix composites.

This type of composites can be classified as

continuous and non-continuous reinforced

materials. One of the more important

nanocomposites is (a) economically producible,

(b) provide for a homogeneous dispersion of

nanotubes in the metallic matrix, and (c) lead to

strong interfacial adhesion between the metallic

matrix and the carbon nanotubes.

1. c. Polymer-matrix nanocomposite

In the simplest case, appropriately adding

nanoparticulates to a polymer matrix can enhance

its performance, often dramatically, by simply

capitalizing on the nature and properties of the

nanoscale filler (these materials are better

described by the term nanofilled polymer

composites).

1. d. Composite material design idea for shielding

mixed radiation what we have done is to design a

shielding material of high performance secures us

or nuclear facilities from radiation. However,

most of you are unfamiliar with nuclear physics,

so here you may consider the nuclear radiation

shielding, the transportation of neutrons and other

particles in material, as small balls with velocity

rolling on the surface of Mars. Admittedly, this

National Conference on Research Advances in Communication, Computation, Electrical Science and Structures (NCRACCESS-2015)

ISSN: 2394 - 2703 www.internationaljournalssrg.org Page 6

hypothesis is questionable, but it may prepare

you for understanding. Now, we take neutron

transportation as an example. In left of Fig.1,

Twenty small bolls of high speed (fast neutrons)

roll towards right on Mars. Some of them, three

or more, trapped by hollows disappear; the others

have collided against the rocks scatter with lower

energy, only a few of them may go across

holding tiny energy (thermal neutrons). Nuclear

reaction cross sections determine probability of

trapping and collision.

2. MATERIALS AND METHODS

2.1. Synthesis of alumina

In the case of AlCl3 (p.a., Fluka) as precursor, the

sol-gel synthesis consisted in the preparation of a

0.1 M AlCl3 ethanolic solution (p.a., Chemical

Company).

By adding a 28% NH3 solution (p.a. Fluka) a gel

was formed. The gel was let to maturate for 30

hours at room temperature and then dried at

100oC for 24 hours.

For C9H21AlO3 (p.a., Fluka) used as precursor,

the sol-gel synthesis consisted in the preparation

of a 0.1 M (C3H7O)3Al ethanolic solution (p.a.,

Chemical Company). A 28% NH3 solution (p.a.,

Fluka) was added in order to form a gel. Mild

shaking at 90oC for10 hours was utilized. The gel

was let to maturate at room temperature for 24

hours, and then dried at 100oC for 24 hours. The

resulting gels were calcined in a furnace for 2

hours (heating rate20oC/min.), at temperature

values of 1000oC and 1200oC.

2.1. a. synthesis of polyaniline

H2SO4 doped films were synthesized by

electrochemical polymerization of aniline on

platinum substrate under potentiometric

conditions at room temperature using

indigenously developed electrochemical

polymerization system. The electrolyte cell

consists of platinum based working and counter

electrode and a saturated calomel reference

electrode was used. Aniline was distilled twice

before use. The electrolyte was prepared using

de-ionized water at room temperature. The

aniline monomer with different concentrations

(0×1 M, 0×2 M, 0×3 M, 0×5 M) was used. Three

electrolytes H2SO4, HCl and HNO3 were used

for investigation. Three different concentrations

of H2SO4 (0×5 M, 1 M, 1×5 M) were studied.

After deposition, the working electrode was

removed from the electrolyte and washed

*Author for correspondence

(mdshirsat_bamu@yahoo.co.in) with supporting

electrolyte solution. The polyaniline film were

characterized by four-probe technique.

2.1. B.Synthesis of BNNT

In the present investigations a mixture of

NaBH4and NH4Cl (99.9 %, Merck, Germany )

having a weight ratio of 1:1, was heated in a

tubular furnace at temperatures ranging from

600 to 700ºC in the presence of nitrogen

atmosphere for about 2 h followed by

quenching the reaction product in air. From a

series of experiments, it was concluded that best

results were obtained when this mixture was

heated at about 850˚C.for the duration of 1hr in

the presence of nitrogen atmosphere this is for

converting the disordered BN powder in to

BNNT. The following chemical reaction took

place in the preparation of nanostructure BN

powder:

NaBH4+ NH4Cl NaCl + aBN +4H2

3. Results and discussion

3.1X-RAY DIFRACTION ANALYSIS:

National Conference on Research Advances in Communication, Computation, Electrical Science and Structures (NCRACCESS-2015)

ISSN: 2394 - 2703 www.internationaljournalssrg.org Page 7

Fig 3.1. XRD pattern of BNNT

Figure 3.1 displays the typical XRD pattern of

the as-synthesized BN nanotubes. Four peaks at -

spacing’s of 3.35, 2.17, 2.07, 1.67, and 1.25  Å

can be indexed as (002), (100), (101), (004), and

(110) planes of hexagonal boron nitride. The

lattice constants are Å and Å, close to the

reported value and Å in JCPDF card no. 45-0893,

indicating the good crystallinity of the BN

nanotubes.

3.2. SCANNING ELECTRON MICROSCOPE

(SEM):

Fig 3.2.SEM image of BNNT

The typical SEM image of as-synthesized BN

nanotubes is shown in Figure 5.2, which indicates

the products possess a high density of one-

dimensional structures with diameters in the

range of 30–200  nm and an average of about

150  nm. The average lengths of the structures

are more than 10  μm. Few BN flakes and

particles were observed. The purity of BN

nanotubes was estimated of about 95 wt%.

3.3.FOURIER TRANSFORMS INFRARED

SPECTROSCOPY (FTIR):

Fig 5.3: FTIR pattern of BNNT

Figure 5.3 shows the typical wide-scan FTIR

spectrum in the range of 500 to 4000  cm-1 of

the as-synthesized BN nanotubes sample. Two

strong peaks located at 803 and 1379  cm-1 can

be ascribed to the out-of-plane B-N TO models of

the sp2-bonded h-BN and the B-N-B in-plane

bonding vibrations, respectively. The broad

absorption band near 3454  cm-1 can be resulted

from the O–H bonds due to the absorbed of

water. As shown in Figure5.3, a peak at

1535  cm-1 in the deconvolution spectrum

should be assigned to the unique stretching of the

h-BN network around the circumference of BN

nanotubes, while the other peak at 1117  cm-1 in

the deconvolution spectrum may be attributed to

the abnormal vibrations like those of quartzite

BN, which may exist due to structure defects in

the as-synthesized cylindrical BN nanotubes.

3.4. X-ray Diffraction

Fom different precursors, dried and heat treated

for 2 hours at temperature valuesof 1000oC or

1200oC. It should be noticed that when AlCl3

was used as aprecursor, the dried gel highlights

the presence of AlCl3 ·6H2O crystal (ICDD 73-

0301), (Fig. 1a). Thermal treatment at 1000oC for

two hours leads to its

Decomposition with the formation of a mixture of

γ-Al2O3 (ICDD 29-0063) andα-Al2O3 (ICDD

48-0366). Increasing the temperature of

National Conference on Research Advances in Communication, Computation, Electrical Science and Structures (NCRACCESS-2015)

ISSN: 2394 - 2703 www.internationaljournalssrg.org Page 8

heattreatment up to 1200oC for two hours results

in the formation of only α-Al2O3(ICDD 48-

0366), (Fig. 1c) [5].In the case of the organic

precursor (C3H7O)3Al, a poorly crystalline

driedgel can be observed (Fig. 2a), revealed by a

halo in the small angles interval.Thermal

treatment at 1000oC leads to the formation of an

α + γ - Al2O3 mixture(ICDD 48-0366, ICDD 29-

0063),, having relatively low degrees of

crystallinity(the halo at 30-45 degrees).

Increasing the heat treatment temperature to

1200oCleads to the formation of α-Al2O3 (ICDD

48-0366) and a higher crystallinity. The

crystallite size values of α-Al2O3 are shown in

Table 1. It should be observedthat, as the heat

treatment temperature increases, the crystallite

size increases, and this increase being more

important in the case of the organic precursor.

Irrespective ofthe precursor used, thermal

treatment at 1200oC leads to crystallite sizes

ofapproximately the same value.

Conclusions

The high quality boron nitride nanotubes were

synthesized by chemical vapour deposition

method. The synthesized boron nitride nanotubes

were characterized by X-ray diffraction (XRD)

and scanning electron microscopy (SEM). Also,

alumina nanoparticles have been synthesized by

sol gel method and the crystalline phase of the

sample was characterized by XRD.Then prepared

samples going to be preparing nanocomposites by

solvent casting method then this composite

material was dispersed in polyaniline. The above

synthesized polymer matrix composite material

have to be coated over the titanium alloy sheet for

excellent radiation shielding property.

REFERENCES

1. H R Williams, R S Trask and I P Bond, ACCIS—

Advanced Composites Centre for Innovation and

Science, Department of Aerospace Engineering,

University of Bristol, Queen’s Building, University

Walk, Bristol BS8 1TR, UK.

2. S. Bellucci,* C. Balasubramanian, G. De Bellis, F.

Micciulla, G. Rinaldi WILEY-VCH Verlag GmbH &

Co. KGaA, Weinheim.Macromol. Symp. 2008,

3. Suraj Rawal and James Brantley Lockheed Martin

Space Systems Company Denver, CO 80201

USA,Nafiz KarabudakLockheed Martin Corporation

Corporate HQ, Bethesda, MD 20817

USA.Development of Carbon Nanotube-based

Composite for Spacecraft Components.

4. T. Gibson, B. Rice, W. Ragland, E.M. Silverman, H.

Peng, K. Strong, and D. Moon, ―Formulation and

Evaluation of Carbon Nanofiber-Based Conductive

Adhesives,‖ Society of Advanced Materials and

Processes,Longbeach, June 2004.

5. P.S.S. Gouda, R. Kulkarni, S.N. Kurbet, and D. Jawali,

―Effect of multiwalled carbon nanotubes and graphene

on the mechanical properties of hybrid composites,‖

Advanced Materials Letters, March 2013.

6. S.P. Rawal, ―Multifunctional Carbon Nanocomposites

Coatings for Space Structures,‖ AIAA

SDMConference, May 4-7, 2006, Newport, RI.B. Rice,

T. Gibson, and L. Lafdi, ―Development of

Multifunctional Advanced Composites using a VGNF

Enhanced Matrix,‖ Society of Advanced Materials and

Processes, June2004

7. Ronald F. Gibson Department of Mechanical

Engineering, University of Nevada, Reno, MS-312,

Reno, NV 89557, United States. A review of recent

research on mechanics of multifunctional composite

materials and structures.

8. James C. Williams a,∗, Edgar A. Starke, Jr.a Materials

Science & Engineering Department, The Ohio State

University, 142 Hitchcock Hall, 2070 Neil Ave,

Columbus, OH 43210, USAb Materials Science &

Engineering Department, The University of Virginia,

Thornton Hall, Room B102A, Charlottesville, VA

22903, USA.

National Conference on Research Advances in Communication, Computation, Electrical Science and Structures (NCRACCESS-2015)

ISSN: 2394 - 2703 www.internationaljournalssrg.org Page 9

9. Polymer IJ, Couper MJ. Design and development of an

experimental wrought aluminium alloy for use at

elevated temperatures. Metal Trans 1988.

10. Zhu AW, Gable BM, Shiflet GJ, Starke Jr. EA. The

intelligent design of age hardenable wrought aluminium

alloys. Advanced Engineering Materials 2002.

11. S K Singhal*, A K Srivastava, B P Singh & Anil K

GuptaNational Physical Laboratory, Dr K S Krishnan

Road, New Delhi110 012, India. Synthesis and

characterization of boron nitride nanotubes using a

simple chemical method.

12. MasaIshigami, ShaulAloni, and A. Zettl, Physics

Department, University of California at Berkeley,

Berkeley, CA 94720 USA. Materials Sciences Division,

Lawrence Berkeley National Berkeley Laboratory,

Berkeley, CA 94720, USA.

13. Ching-Yuan Su, Wen-Yi Chu, Zhen-Yu Juang, Ko-

Feng Chen, Bing-Ming Cheng, Fu-Rong Chen, Keh-

ChyangLeou, and Chuen-Horng Tsai*, Department of

Engineering and System Science, National

TsingHuaUniVersity, Hsinchu, Taiwan.

1

Synthesis of mesoporous NiCo2O4/PANI

composites by sol-gel methodologies of electrodes

for supercapacitors applications

P.Tamilarasan*1, K.Rajasekar and E.Muthusankar

ABSTRACT — Nickel cobaltite (NiCo2O4)/ polyaniline (PANI)

composites by sol-gel methodologies of electrode materials for

supercapacitors. Virgin and composited material were going to

be characterized by a complementary combination of X-ray

diffraction, Brunauer−Emmett−Teller (BET) for surface area

measurements, and morphological studies through Scanning

Electron Microscopy (SEM). The performance of the assembled

NiCo2O4 / PANI supercapacitors is going to be studied by cyclic

voltammetry (CV). The electrochemical properties of the

supercapacitors will be investigated by galvanostatic charge–

discharge, and electrochemical impedance spectroscopy (EIS).

The expected specific capacitance of the composite materials will

be around 700 Fg-1.

.

Keywords: Nickel cobaltite, Polyaniline, Nanocomposites,

Supercapacitors,

I. INTRODUCTION

SUPERCAPACITORS, also known as

Electrochemical or electric double layer capacitor made from

high surface area electrodes. They are also used in high power

applications such as load leveling and Electric Hybrid

Vehicles (EHV), where short duration, high power pulses are

required. Supercapacitors are used in parallel with batteries

and fuel cells. The life time of a battery system or fuel cell

system can be increased by using supercapacitor instead of

standalone battery or fuel cell. In these systems, control

strategy also plays key role in effective use of supercapacitor .

They are generally classified into three different types : i.e., (i)

electrochemical double-layer capacitor (EDLC), works under

principle of non-faradaic mechanism that means it stores

charge electrostatically. It does not involve any chemical

reaction or charge transfer EDLC is highly reversible and

stable over more than 106 cycles. Its performance could also

be altered by using different electrolytes. The capacitance for

acidic electrolyte is higher than the basic electrolyte. Carbon

materials are generally used as electrode materials for EDLC

because these electrode materials generally have higher

surface area and lower cost. As voltage is applied between the

electrodes, it attracts oppositely charged ions in the electrolyte

where it diffuses at the pores of electrode. The electrode

materials are engineered to prevent the recombination. It leads

to formation of electric double layer and store energy. Also, it

is having much higher surface area and much thinner

dielectric medium contributes more energy storage in the

supercapacitors. (ii) Pseudo Capacitors stores energy

faradaically through the charge transfer between the electrode

and electrolyte. These faradaic processes may allow

pseudocapacitors to achieve greater capacitances and energy

densities than EDLCs. But it is having lower reversibility and

cycle stability than EDLC. There are two electrodes materials

that are used to store charge in pseudocapacitors: conducting

polymers and metal oxides. Conducting polymers

(polyaniline, polypyrole, polythiophene) and metal oxides

(RuO2, NiO2, MnO2, etc.) are generally used as electrode

material in the case of pseudocapacitor. The

Pseudocapacitance arises by following process:

electrochemical properties, oxidation-reduction reactions and

intercalation. It allows capacitor with higher energy density

and capacitance when compared to EDLC.

(iii) Hybrid capacitors are designed to incorporate the behavior both EDLC and Pseudocapacitance. One electrode material is made with EDLC behavior and another with Pseudocapacitance behavior. Hence hybrid capacitor can achieve higher energy density and stability. Although hybrid capacitors have been explored less than EDLCs or pseudocapacitors, the research that is available suggests that they may be able to outperform comparable EDLCs and pseudocapacitors. Recently, the mixed metal (mixed transition metal)

oxides with stoichiometric or non-stoichiometric compositions

have attracted tremendous research interest primarily due to

their outstanding electrochemical properties, rich redox

reactions involving different ions, complex chemical

compositions and their synergetic effects. When compared to

simple metal oxides, mixed metal oxides exhibit high.

2

electrical conductivity due to lower activation energy for

electron transfer between cations. A number of single phase

binary metal oxide systems such as CuFe2O4, NiMnCo2O4,

MnFe2O4, ZnCo2O4, MnCo2O4, CoFe2O4 4, NiCo2O4, and their

composites CoFe2O4/graphene, NiFe2O4 /PANI, NiCo2O4

/graphene, NiCo2O4 CN and NiCo2O4 /carbon cloth have been

reported. Among these oxides, the spinel NiCo2O4 has been

emerging as high performance electrode material for ECs.

NiCo2O4 exhibits good electrical conductivity, low-cost,

environmentally benign, natural abundant, high theoretical

capacitance, and rich redox reactions which originate from

both nickel and cobalt cations. As a result it evinces promising

electrochemical properties and could be an alternative

pseudocapacitive material to RuO2. Moreover, NiCo2O4 can

be synthesized with diverse structural morphologies such as

nanowires, nanoflowers, nanorods, nanotubes, nanosheets,

nanoneedles, nanoparticles and nanoflakes by hydrothermal,

solvothermal, precipitation, solegel and microwave assisted

methods.

Polyaniline (PANI) is one of the most intensively investigated

Conducting polymers due to its excellent environmental

stability, case of synthesis, and relatively high level of

electrical conductivity. Now, studied PANI has been widely

studied for potential application in many domains such as

electro chromic device rechargeable batteries, electromagnetic

interference shielding, and sensors. Since the time Deberry

found the protective effect of PANI on iron-based metal the

anti-corrosion application of PANI attracted enormous interest

among researchers.

II. EXPERIMENTAL METHODS

2.1 Chemical and apparatus required

Analytical grade NiCl2.6H2O (99.9%, CDH

chemicals, India), CoCl2.6H2O (99%, SDFCL chemicals,

India), cetyltrimethylammonium bromide (CTAB) (99%,

Spectrochem chemicals, India) and urea (Thames-Baker) were

used as purchased without further purification. The purchased

from Merck. The deionized water (NICE chemicals, India)

was used during all synthesis procedures.

2.2 Materials preparation of NiCo2O4

In a typical synthesis 15 mmol NiCl2.6H2Oand 30

mmol CoCl2.6H2O (Ni and Co, Molar ratio 1:2) were

dissolved in 100 mL of deionized water and added 22.5 mmol

CTAB dissolved in 100 mL of water. The mixture was stirred

for 1 h to form homogeneous solution and then 90 mmol of

solid urea was added to this solution, continued stirring for 3 h

to get complete homogeneity. The resulting solution was then

divided into two equal halves and transferred to two different

Teflon lined stainless steel autoclaves of 150 mL capacity.

The reactions in these two autoclaves were separately carried

out at 120 ◦C in an electrical oven for 48 h. The autoclaves

were cooled to room temperature and the light pink color

precipitate was separated by centrifugation at 4000 rpm. The

product was repeatedly washed with deionized water, and a

mixture of water and absolute ethanol, and finally with

absolute ethanol for three times. The obtained products were

dried in an oven at 60 ◦C for 12 h. The samples were calcined

at 350 ◦C for 3 h. the finally obtained block color sample.

2.3 Materials preparation of PANI

Aniline (AN), sulfuric acid (H2SO4), hydrochloric

acid (HCl), phosphoric acid (H3PO4), ammonium

peroxydisulfate (ASP), Nitric acid (HNO3), purchased from

the industry of fine chemicals. All the raw materials were used

directly as received without purification. The 70ml of (0.1M)

aniline, 30ml of (1M) sulfuric acid (H2SO4), two solution

mixed by magnetic stirred for 15 min. after that 20ml of

(0.1M) potassium dichromate (K2Cr2O7), drop wise added

solution for 30 min with 60◦C magnetic stirred. After 5 min,

dark- green formed slowly at the interface and then gradually

diffused into the aqueous phase. After few min, the entire

aqueous phase was filled homogenously with dark-green color

film. the residue of polymer thus obtained is purified and

dried in a vacuum oven at 25 ◦C for 24 hr.

2.4 Synthesis of NiCo2O4/ PANI composite materials

The composite materials prepared by ball milling, normal wet

Chemical methods, sol-gel methods, etc. Nano composites

materials of NiCo2O4 have been synthesized by hydrothermal

method. (0.5g) of NiCo2O4 and 0.5 g of aniline is dissolved in

20ml of CHCl3. 0.1 M ammonium persulfate is dissolved in

1.0 M and NiCo2O4 same is slowly added to the above mixture

of aqueous and organic phase. After 5 min, dark-green formed

slowly at the interface and then gradually diffused into the

aqueous phase. After 24 hr, the entire aqueous phase was

filled homogenously with dark-green color film, organic layer

observed shows orange color due to the formation of aniline.

The aqueous phase was then collected, and washed with

ethanol and water to remove the unreacted aniline. The

residue of polymer thus obtained is purified and dried in

vacuum oven at 40◦C for 36 hr. the dried polymer composites

sample is used for the structural characterization.

III. CHARACHERIZATION TECHNIQUES

Thermogravimetry analysis of obtained precursor

samples were performed on TA make TGA Q500V20.10

Build 36 instrument, in air flow and with linear heating rate of

20 ◦C per min, from room temperature to 800 _C. The powder

X-ray diffraction (PXRD) patterns were obtained using Bruker

AXS D8 advanced diffractometer at room temperature using

Cu Ka (λ= 0.15406 nm) radiation generated at 40 kV and 30

mA with scan rate of 0.02_ per min from 10 to 80_. The

(220), (311), (511) and (440) peaks have been used to obtain

the average crystallite sizes of NiCo2O4 samples by Scherrer

method. Nitrogen adsorption and desorption experiments were

carried out on Micromeritics ASAP 2020 analyzer.. The

specific surface area was calculated using Brunauere-

Emmette-Teller (BET) method, and pore size distribution of

the samples was obtained from BarreteJoynereHalenda (BJH)

method. Surface morphologies of as synthesized and calcined

products were examined by field emission scanning electron

microscope (SEM, FEI, Quanta 400). The powder samples

3

were deposited on conducting carbon tape before mounting on

the microscope sample holder for SEM analysis. High-

resolution transmission electron microscope (HR-TEM)

images were obtained using JOEL JEM-3010 machine

operated at 200 kV. The electrochemical properties of the

supercapacitors will be investigated by galvanostatic charge–

discharge, and electrochemical impedance spectroscopy (EIS).

VI.RESULTS AND DISCUSSION

4.1. TGA and XRD of NiCo2O4

Metal hydroxy carbonate precursor salts were

obtained by Reacting metal cations with anions (OH_ and

CO32 ) by slow hydrolysis of urea in aqueous media. The

XRD of final calcined products shown in Fig. 1A confirm the

formation of mixed metal oxide phases. The TGA

measurements of these samples show that they can be

decomposed completely to metal oxides at 350 ◦C (Fig. 1B).

Fig. 1-(A) XRD patterns of calcined products of precursors at

350 ◦C (NiCoO-120-cal)

Fig. 1-(B) the TGA measurements of these samples show that

they can be decomposed completely to metal oxides at 350 ◦C

4.2. X-ray Diffraction of NiCo2O4/PANI composites:

The crystallinity and chain packing of the synthesized

polymer-composites were examined by X-ray diffraction analysis. The Figure 2 (a-b) shows the characteristic peak of Pani with other four main peaks at 2θ= 31.950, 38.30, 45.50

and 65.50 correspond to (220), (222) (400) & (440) matching

with the JCPDS pattern ofNiCo3O4 nanoparticles

Figure 2 (a-b) XRD patterns of NiCo2O4/PANI

4

4.3. FTIR Spectroscopy Studies

Figure 1 (a-b) shows FTIR spectra of the polymer nano-

composite samples. The bands at 1563 and 1481 cm are

attributed to C=N and C=C stretching mode of vibration for

the quinonoid and benzenoid units of Pani. The peaks at 1300

and 1236 cm-1 are assigned to C– N stretching mode of

benzenoid ring. The peak at 1239 cm-1 is the characteristic of

the conducting protonated form of Pani[23,24]. The bands in

the region 1000– 1110 cm-1 are due to in plane bending

vibration of C– H mode. The band at 820 cm-1 originates out

of plane C– H bending vibration. FTIR spectrum of the

polymer composites shows two peaks at 665 and 703cm-1;

which are attributed to the presence of cobalt oxide in the

polymer nanocomposite (Figure 1.b). These two peaks closely

match the reported values of the optical vibration modes of

NiCo3O4[25]. For the Pani-NiCo3O4 composites its IR

spectrum is almost identical to that of the pure pani but all

bands shift slightly towards red (lower frequency side), and

the intensity ratio of quinonoid band has also changed. These

results indicate that some interactions (kind of weak Vander

Waals force of attraction) exist between pani and nano NI

Co3O4.

Figure.1 (a-b) shows FTIR spectra of the polymer nano-

composite samples

4.4. Scanning Electron Microscopy

Figure 4. (a-b): SEM images of Polyaniline nickel Cobaltite

oxide at low and high magnifications

The scanning electron micrograph (SEM) of the nano-

composite samples at low ad high magnifications are shown in

Figure 4(a-b). The NiCo3O4 particles are well dispersed and

are of spherical shape with uniform diameter lying in the

range from 1μm to 100 nm. A uniform morphology and

chemical homogeneity observed

4. Conclusions

Nickel cobaltite (NiCo2O4)/ polyaniline (PANI)

composites by sol-gel methodologies of electrode materials

for supercapacitors. Virgin and composited material were

going to be characterized by a complementary combination of

X-ray diffraction, Brunauer−Emmett−Teller (BET) for surface

area measurements, and morphological studies through

Scanning Electron Microscopy (SEM). The performance of

the assembled NiCo2O4 / PANI supercapacitors is going to be

studied by cyclic voltammetry (CV). The electrochemical

properties of the supercapacitors will be investigated by

galvanostatic charge–discharge, and electrochemical

impedance spectroscopy (EIS). The expected specific

capacitance of the composite materials will be around 700 Fg1

REFERENCES

1] Zhang Y, Feng H, Wu X, Wang L, Zhang A, Xia T, et al.

Progress of electrochemical capacitor electrode materials: a

review. Int J Hydrogen Energy 2009;34:4889e99.

[2] Hall PJ, Mirzaeian M, Fletcher SI, Sillars FB, Rennie AJR,

Shitta-Bey GO, et al. Energy storage in electrochemical

capacitors: designing functional materials to improve

performance. Energy Environ Sci 2010;3:1238e51.

[3] Yuan C, Wu HB, Xie Y, Lou XW. Mixed transition-metal

oxides: design, synthesis, and energy-related applications.

Angew Chem-Int Ed 2014;53:1488e504.

[4] Simon P, Gogotsi Y. Materials for electrochemical

capacitors. Nat Mater 2008;7:845e54.

[5] Xia X, Chao D, Fan Z, Guan C, Cao X, Zhang H, et al. A

new type of porous graphite foams and their integrated

composites with oxide/polymer core/shell nanowires for

supercapacitors: structural design, fabrication, and full

supercapacitor demonstrations. Nano Lett 2014;14:1651e8.

[6] Kotz R, Carlen M. Principles and applications of

electrochemical capacitors 2000;45:2483e98.

[7] Zhang LL, Zhao XS. Carbon-based materials as

supercapacitor electrodes. Chem Soc Rev 2009;38:2520e31.

[8] Ramya R, Sivasubramanian R, Sangaranarayanan MV.

Conducting polymers-based electrochemical supercapacitors-

progress and prospects. Electrochim Acta 2013;101:109e29.

[9] Jiang J, Li Y, Liu J, Huang X, Yuan C, Lou XW. Recent

5

advances in metal oxide-based electrode architecture design

for electrochemical energy storage. Adv Mater

2012;24:5166e80.

[10] Hu C-C, Chang K-H, Lin M-C, Wu Y-T. Design and

tailoring of the nanotubular arrayed architecture of hydrous

RuO2 for next generation supercapacitors. Nano Lett

2006;6:2690e5.

[11] Zhang Y, Li GY, Lv Y, Wang LZ, Zhang AQ, Song YH,

et al. Electrochemical investigation of MnO2 electrode

material for supercapacitors. Int J Hydrogen Energy

2011;36:11760e6.

[12] Ahmed, S.R., Ogale, S.B., Ramesh, R., Papaefthymiou,

G.C., Kofinas, P., 2002. Magnetic Properties of CoFe2O4

Nano-particles Synthesized through a Block co-polymer

Nano-reactor Route. Appl. Phys. Lett., 80:1616.

[13] Govindraj, B., Sastry, N.V., Venkataraman, A., 2004.

Ther-mal and Morphological Studies on γ-Fe2O3 Polystyrene

Composites and the effect of Additives. J. Appl. Polym. Sci.

93: 778-788.

[14] Mallikarjun, N.N., Manohar, S.K., Kulkarni, P.V.,

Venkata-raman, A., Aminabhavi, T. M., 2005. Novel high

dielectric constant nanocomposites of polyanaline dispersed

with γ-Fe2O3 nanoparticals J. Appl. Polym. Sci. 97:1868-

1874.

[15] Gilman, J.W., 1999. Flammability and thermal stability

stu-dies of polymer layered-silicate (clay) nanocomposites.

.Appl. Clay Sci. 15:31-49.

[16] Gilman, J.W., Jackson, C.L., Morgan, A.B., Harris J.R.,

Manias, E., Giannelis, E.P., Wuthenow, M., Hilton, D., Phil-

lips, S.H., 2000. Flammability properties of polymer-layered

silicate nanocomposites. Polypropylene and polystyrene na-

nocomposites. Chem. Mater. 12:1866-1873.

[17] Porter, D., Metcalfe, E., Thomas, M.J.K., 2000.

Nanocom-posite fire retardants—a review. Fire Mater 24, 45-

52.