69 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

ISSN 2277 – 7164

Original Article

Humidity Sensing Study of Polypyrrole/Zirconium Oxide Composites

Chaluvaraju B V1, Sangappa K Ganiger2, Uma V3 and Murugendrappa M V4

1Department of Physics, Bangalore Institute of Technology, Bangalore-560004, Karnataka, India 2Department of Physics, Government Engineering College, Raichur-584134, Karnataka, India

3Department of Electronics, Mount Carmel College, Bangalore, Karnataka, India 4Department of Physics, B.M.S. College of Engineering, Bangalore-560019, Karnataka,India

E-mail: bvcgowda@gmail.com

Received 09 December 2014; accepted 24 December 2014 Abstract

In-situ polymerization of pyrrole was carried out with zirconium oxide, in the presence of oxidizing agent ammonium

persulphate, to synthesize polypyrrole/zirconium oxide composites, by chemical oxidation method. The

polypyrrole/zirconium oxide composites were synthesized with various compositions viz., 10, 20, 30, 40 and 50 wt. % of

zirconium oxide in pyrrole. The powder X-ray diffraction spectrographs suggest that they exhibit semi-crystalline

behavior. Fourier Transform Infra-Red Spectroscopy shows that, the stretching frequencies are shifted towards higher

frequency side. The surface morphologies of these composites studied using Scanning Electron Microscopy indicate that

zirconium oxide particles are embedded in the polypyrrole (PPy) chain, to form multiple phases. Thermographs of thermal

analysis also imply that the polypyrrole/zirconium oxide composites have stronger stability than PPy. The observation of

UV-VIS-NIR spectrum is proof of an interaction between polypyrrole/zirconium oxide. The resistance of the

polypyrrole/zirconium oxide composites on exposure to a humid environment, increases from 144 ohm to 483 ohm, with

increase in humidity conditions from 24 % to 95.8 %.

© 2014 Universal Research Publications. All rights reserved

Key Words: Polypyrrole; Zirconium Oxide; Composite; Conductivity; Resistance; Humidity.

Introduction: Beside of demand of the humidity sensor, mainly electric

output-based sensor, gradually increase, sensor

development is also necessary to be carried out due to some

drawbacks of the current sensors which were mainly

affected by their sensing element material as reported by

some researchers. Hence, investigations of new material

sensor or combination of some materials have to be

continuously proceeded to improve the sensor performance

characteristics [1].

Humidity measurements displays an extensive influence

and are widely applied in modern industry [2-3],

agriculture [3-4], medicine [6-7], scientific research [8-9]

and so on as well as people's daily lives. There is a

substantial interest in the development of sensors for

application in monitoring and detecting humidity in

moisture-sensitive environment, such as glove boxes and

clean rooms. Therefore, humidity sensors have attracted

tremendous attention for the purpose of detecting the

humidity. In order to optimize important properties like

drift, accuracy, hysteresis or temperature influences of

humidity sensors, recently new materials including metal

oxide [10-11], ceramic [11-12] and polymers [13-14] have

been designed as humidity sensors. Most commercially

used humidity sensors with porous ceramics or metal

oxides obviously are not suitable due to a large thickness or

a complex integration process [10-12].

Especially, polymer electrolytes, as one of the most

interesting materials, have been identified as good

candidates having a better humidity-sensitive characteristic,

such as reliability, ease of processing and the low

fabrication cost for the preparation of resistive-type

humidity sensors in the past years.

Experimental

Synthesis AR grade [SpectroChem Pvt. Ltd.] pyrrole [15] was

purified by distillation under reduced pressure. 0.3 M

pyrrole solution taken in a beaker was placed in an ice tray

mounted on a magnetic stirrer. 0.06 M ammonium

persulphate [16] solution was continuously added, drop-

wise with the help of a burette, to the above 0.3 M pyrrole

solution. The reaction was carried on for 5 hours under

continuous stirring, maintaining a temperature of 0 °C to 5

°C. The precipitated polypyrrole was filtered, dried in a hot

air oven and subsequently in a muffle furnace at 100 °C.

The yield of the polypyrrole was 3.2 g (to be taken as 100

wt. %). 0.32 g (10 wt. %) of ZrO2 was added to a 0.3 M

pyrrole solution and mixed thoroughly. 0.06 M ammonium

Available online at http://www.urpjournals.com

Advances in Polymer Science and Technology: An International Journal

Universal Research Publications. All rights reserved

70 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

persulphate was then continuously added drop-wise with

the help of a burette to the above solution, to get PPy/ZrO2

10 wt.% composite. Similarly, for 20, 30, 40 and 50 wt. %,

0.64 g, .96 g, 1.28 g and 1.6 g of ZrO2 [Sisco Research Lab

Ltd.] powder [17] were taken and the above procedure

repeated to get the PPy/ZrO2 composites. Pure PPy and

PPy/ZrO2 powder were pressed in the form of pellets of 10

mm diameter using a hydraulic press [Shimazdu, Japan].

Conducting silver paste was applied to the pellets of

synthesized composites for measurements. The humidity

response measurements were done by Humidity Sensor (V

B Ceramic Consultant, Chenni, India) for the

PPy/ZrO2 composites in the cooling temperature range

between 70 °C and 0 °C.

Characterization The X-ray diffraction patterns of the PPy/ZrO2 composites

were recorded on X-ray Diffractometer (Bruker AXS D8

Advance) using Cu kα radiation (λ = 1.5418 Å) in the 2θ

range 20°–80°. The FTIR spectra of the PPy/ZrO2

composites were recorded on IR Affinity-1 (Shimadzu,

Japan) spectrometer in KBr medium at room temperature

and the SEM images studied using Scanning Electron

Microscope (Jeol 6390 LV). Thermal analysis studies were

done in the temperature range from 40 °C to 740 °C at a

heating rate of 20 °C/min for the pure PPy, PPy/ZrO2

composites and ZrO2 using Thermal Analysis System

(TG/DTA) (Perkin Elmer STA 6000 Diamond TG/DTA).

The UV-VIS spectra for the pure PPy and PPy/ZrO2

composite were recorded using UV-VIS-NIR

Spectrophotometer (Varian Carry 6000).

Results and discussion

XRD Analysis

Figure 1 represents X-ray diffraction pattern of the pure

PPy, which has a broad peak at about 2θ = 25°, a

characteristic peak of amorphous polypyrrole. In the XRD

pattern of PPy/ZrO2 composites, characteristic peaks

(Figure 2) are indexed by lattice parameter values.

Characteristic peaks are indexed by lattice parameter

values. Main peaks are observed with 2θ at 22.28, 34.24,

38.72, 49.32, 54.05, 59.92 and 65.72 with respect to inter-

planar spacing (d) 3.15, 2.61, 2.32, 2.21, 1.70, 1.54 and

1.42. In depth analysis of X-ray diffraction of PPy/ZrO2

composites suggests that it exhibits semi-crystalline

behavior. Figure 2.f represents the XRD pattern of ZrO2

revealing the partial crystalline nature [18-21].

Figure 1 X-Ray diffraction pattern of the pure PPy

20 30 40 50 60 70 80

0

500

1000

1500

2000

2500

Lin

es (

co

un

ts)

2

(a) PPy/ZrO2 10%

20 30 40 50 60 70 80

0

500

1000

1500

2000

2500

3000

3500

line

s (C

ou

nts

)

2

(b) PPy/ZrO2 20%

20 30 40 50 60 70 80

0

1000

2000

3000

4000

5000

6000

Lin

es (

Co

un

ts)

2

(c) PPy/ZrO2 30%

20 30 40 50 60 70 80

0

1000

2000

3000

4000

5000

Lin

es (

Co

un

ts)

2

(d) PPy/ZrO2 40%

20 30 40 50 60 70 80

0

1000

2000

3000

4000

5000

6000

7000

Lin

es (

Co

un

ts)

2

(e) PPy/ZrO2 50%

20 30 40 50 60 70 80

0

1000

2000

3000

4000

5000

6000

7000

8000

Lin

es (

Co

un

ts)

2

(f) ZrO2

Figure 2 X-Ray diffraction patterns of (a), (b), (c), (d), (e)

for PPy/ZrO2 (wt. 10%, 20%, 30%, 40% & 50%)

composites and (f) ZrO2

FTIR Analysis

Figure 3 FTIR spectrum of the pure PPy

The FTIR spectra of Pure PPy, PPy/ZrO2 composites and

ZrO2 are shown in Figures 2 and 3. The characteristic

stretching frequencies may be attributed to the presence of

C = N stretching, N – H bending deformation, C – N

stretching and C – H bending deformations for composites.

In comparison with pure PPy and ZrO2, the stretching

frequencies are shifted towards the higher frequency

side.This indicates that there is homogeneous distribution

of ZrO2 particles in the polymeric chain, due to the Van der

walls interaction between polymeric chain and ZrO2 [22-

29].

4000 3500 3000 2500 2000 1500 1000 500

0

10

20

30

40

50

Tra

nsm

ittan

ce in

%

Wave number in cm-1

Pure PPy

71 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

3000 2500 2000 1500 1000 500

0

5

10

15

20

25

30

Tra

nsm

ittan

ace

in %

wave number in cm-1

(a) PPy/ZrO2 10%

3000 2500 2000 1500 1000 500

0

2

4

6

8

10

12

Tra

nsm

ittan

ce in

%

Wave number in cm-1

(b) PPy/ZrO2 20%

3000 2500 2000 1500 1000 500

-2

0

2

4

6

8

10

12

14

16

Tra

nsm

itta

nce

in %

wave number in cm-1

(c) PPy/ZrO2 30%

3000 2500 2000 1500 1000 500

10

20

30

40

50

60

70

Tra

nm

itta

nce

%

Wavenumber in cm-1

(d) PPy/ZrO2 40%

3000 2500 2000 1500 1000 500

10

20

30

40

50

60

70

80

90

Tra

nsm

itta

nce

in %

Wave number in cm-1

(e) PPy/ZrO2 50%

3000 2500 2000 1500 1000 500

-10

0

10

20

30

40

50

60

70

80

Tra

nsm

itta

nce

in %

Wave number in cm-1

(f) ZrO2

Figure 4 FTIR spectra of (a), (b), (c), (d), (e) for PPy/ZrO2 (wt. 10%, 20%, 30%, 40% & 50%) composites and (f). ZrO2

SEM Analysis

Figure 5 SEM Micrograph of the Pure PPy

72 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

a. PPy/ZrO2 (wt. 10%) b. PPy/ZrO2 (wt. 20%)

c. PPy/ZrO2 (wt. 30%)

e. PPy/ZrO2 (wt. 50%) f. ZrO2

d. PPy/ZrO2 (wt. 40%)

Figure 6 SEM micrographs of (a), (b), (c), (d), (e) for PPy/ZrO2 (wt. 10%, 20%, 30%, 40% & 50%) composites and (f).

ZrO2

Figures 5, 6 and 6.f are SEM micrographs of Pure PPy,

PPy/ZrO2 composites and ZrO2 respectivly.It is clearly seen

from the SEM micrograph of polypyrrole that, it has

clusters of spherical shaped particles. Elongated chain

patterns of the polypyrrole particles are also observed. The

chemically polymerized polypyrrole samples prepared with

polypyrrole powder have a much larger specific surface

than the electrochemically polymerized film. A granular

morphology of the polypyrrole particle structures is

measured from the SEM micrographs and is found to be

about 1 μ m in diameter [11]. A very high magnification of

the SEM image is indicative of hemi spherical nature of

polymer as clusters in the composites. ZrO2 particles are

embedded in PPy chain to form multiple phases,

presumably because of weak inter-particle interactions [30-

34].

TG/DTA Analysis

The most important and reliable factor in the study of heat

stable polymers is the measurement / evaluation of thermal

stability.

Derivative weight (mg/min) versus temperature is shown in

Figures 7-8 for the pure PPy and PPy/ZrO2 (40%)

composite respectively. For the pure PPy, 0.123 mg/min is

decomposed at 75.21 °C and 0.083 mg/min is decomposed

at 270.93 °C with respect to total weight of the sample i.e.

5.265 mg. For PPy/ ZrO2 (40%) composite, 0.109 mg/min

is decomposed at 75.96 °C and 0.148 mg/min is

decomposed at 276.36 °C with respect to total weight of the

sample i.e. 6.086 mg. It is found that, the weight loss

caused by the volatilization of the small molecules in

PPy/ZrO2 (40%) composite at different temperatures is

slow compared to that of pure PPy and indicates its higher

stability; which clearly proves that ZrO2 was inserted into

73 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

0 100 200 300 400 500 600 700 800

-80

-60

-40

-20

0

20

40

60

80

He

at F

low

En

do

Do

wn

(m

W)

Temperature (°C)

Pure PPy

0 100 200 300 400 500 600 700 800

-0.16

-0.14

-0.12

-0.10

-0.08

-0.06

-0.04

-0.02

0.00

0.02

De

riva

tive

We

igh

t (m

g/m

in)

Temperature (°C)

Pure PPy

0 100 200 300 400 500 600 700 800

50

60

70

80

90

100

We

igh

t P

erc

en

t (%

)

Temperature (°C)

Pure PPy

0 100 200 300 400 500 600 700 800

2.5

3.0

3.5

4.0

4.5

5.0

5.5

We

igh

t (m

g)

Temperature (°C)

Pure PPy

270.93 °C-0.083 mg/min

75.21 °C-0.123 mg/min

Figure 7 TG/DTA thermographs of the Pure PPy

0 100 200 300 400 500 600 700 800

-80

-60

-40

-20

0

20

40

60

80

Hea

t Flo

w E

ndo

Dow

n (m

W)

Temperature (°C)

PPy/ZrO2 wt 40%

0 100 200 300 400 500 600 700 800

-0.20

-0.15

-0.10

-0.05

0.00

0.05

Der

ivat

ive

Wei

ght (

mg/

min

)

Temperature (°C)

PPy/ZrO2 wt. 40%

0 100 200 300 400 500 600 700 800

50

60

70

80

90

100

Wei

ght P

erce

nt (

%)

Temperature (°C)

PPy/ZrO2 wt 40%

0 100 200 300 400 500 600 700 800

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

Wei

ght (

mg)

Temperature (°C)

PPy/ZrO2 wt 40%

75.96 °C-0.109 mg/min 276.36 °C

-0.148 mg/min

Figure 8 TG/DTA thermographs of the PPy/ZrO2 (40%) composite

the PPy to form the composite thereby increasing the

thermal stability of the composite material [30-36].

Weight (mg/min) versus temperature is shown in Figures

4.a - 4.c for the pure PPy, PPy/ZrO2 (40%) composite and

ZrO2 respectively. As temperature increases, weight of the

sample taken decreases linearly for the pure PPy, PPy/ZrO2

(40%) composite and ZrO2.

UV-VIS-NIR Absorption Analysis

Figure 9 UV-VIS-NIR spectra of the PPy and PPy/ZrO2

(40%) composite

Figure 5 (a & b) shows the UV-VIS-NIR spectra of the PPy

and PPy/ZrO2 (40%) composite. In the spectra of PPy/ZrO2

(40%) composite, the B-band or Soret band, representing

the π→π* transition appears at a modified peak position in

the range about 280–320 nm (near UV region), depending

on the concentration used. The absorption band in the

visible region for PPy representing the π→π* transition has

a doublet. The peaks around 900 nm and 1450 nm are

created due to the electron transition from valence band to

the bipolaron band. This observation is proof of an

interaction between PPy and ZrO2 [37-47].

Humidity Sensing Study The mechanism by which the PPy/ZrO2 composites

respond to humidity may be due to the interaction of the

water molecules with ZrO2 in the composite and the

changes in resistance of the composites with respect to the

doping level of ZrO2 in PPy influenced by the

concentration of water molecules surrounding the polymer

chain.

At high humidity, water molecules are trapped by ZrO2,

since ZrO2 has a higher affinity for water. In this situation,

doping level of PPy becomes high and results in high

74 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

resistance. However, at low humidity, some water

molecules are removed from ZrO2 and simultaneously PPy

de-dopes, resulting in lower resistance [48-52].

Figure 10 Resistance as a function of humidity response

for PPy/ZrO2 composites

Figure 11 Humidity response as a function of cooling

temperature for PPy/ZrO2 composites

Figure 12 Humidity response as a function of time for

PPy/ZrO2 composites

Figure 13 Resistance as a function of cooling temperature

for PPy/ZrO2 composites

Figure 14 Resistance as a function of time for PPy/ZrO2

composites

The resistance measurements as varied with Rh is shown in

Figure 10 for the PPy/ZrO2 composites. It is observed that

the resistance increases with increasing humidity response,

which reveals the susceptibility of the PPy/ZrO2 composites

to humidity.

The humidity response versus cooling temperature as well

as time is shown in Figure 11-12 respectively. The

humidity response is varied from 20 % to 95.8 % as

function of cooling temperature / time with multi-phases.

Conclusion The polypyrrole/zirconium oxide composites were

synthesized to tailor the transport properties. Detailed

characterizations of the composites were carried out using

SEM, XRD, FTIR, TG/DTA and UV-VIS-NIR techniques.

The PPy/ZrO2 composites have shown that the resistance

has dependence on humidity and exhibits a very good

response to humidity sensing.

Acknowledgements The authors would like to acknowledge The Principal,

Dr. T. S. Pranesha, HOD, Dept. of Physics, BMSCE,

Bangalore-560019 & BIT, Rajya Vokkaligara Sangha,

Bangalore-560004 for help to all works. We thank

Sophisticated Analytical Instruments Facility (SAIF) of

20 30 40 50 60 70 80 90 100

150

200

250

300

350

400

Re

sis

tan

ce

in

oh

m

Rh in %

PPy/ZrO2 wt 10%

PPy/ZrO2 wt 20%

70 60 50 40 30 20 10 0 -10

20

30

40

50

60

70

80

90

100

Rh

in

%

Cooling Temperature in 0C

PPy/ZrO2 wt 10%

PPy/ZrO2 wt 20%

0 10 20 30 40 50 60

20

30

40

50

60

70

80

90

100

Rh

in %

Time in min

PPy/ZrO2 wt 10%

PPy/ZrO2 wt 20%

70 60 50 40 30 20 10 0 -10

150

200

250

300

350

400

450

500

Re

sis

tan

ce

in

oh

m

Cooling Temperature in %

PPy/ZrO2 wt 10%

PPy/ZrO2 wt 20%

0 10 20 30 40 50 60

100

200

300

400

500

600

700

Re

sist

an

ce in

oh

m

Time in min

PPy/ZrO2 wt 10%

PPy/ZrO2 wt 20%

75 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

Cochin University of Science and Technology, Cochin,

India for SEM, XRD, TG/DTA and UV-VIS-NIR analysis

of the samples.

References: 1. M V Kulkarni, S K Apte, S D Naik, J D Ambekar, B B

Kale, Ink-jet printed conducting polyaniline based

flexible humidity sensor, Sens Actuat B, 178(2013)

140-143.

2. Y Li, C Deng, M J Yang, Novel surface acoustic wave-

impedance humidity sensor based on the composite of

polyaniline and poly vinyl alcohol with a capability of

detecting low humidity, Sens Actuat B, 165 (2012) 7-

12.

3. J H Ding, Z Lu, R Z Wang, G L Shen, L T Xiao,

Piezoelectric immune sensor with gold nanoparticles

enhanced competitive immunoreaction technique for 2,

4-dichlorophenoxyacetic acid quantification, Sens

Actuat B, 193 (2014) 568-573.

4. A H Hade and M K Sengupta, Advance research on

monitoring of soil & remote sensing of vegetation by

various techniques for proper drip irrigation, IOSR J

Agriculture and Veterinary Sci, 7(2014) 75-83.

5. G H Hui, S S Mi, Q Q Chen, X Chen, Sweet and bitter

tastant discrimination from complex chemical mixtures

using taste cell-based sensor, Sens Actuat B,

192(2014) 361-368.

6. M M Rahman, S B Khan, M Faisal, A M Asiri, M A

Tariq, Detection of aprepitant drug based on low-

dimensional un-doped iron oxide nanoparticles

prepared by a solution method, Electrochimica Acta,

75 (2012) 164-170.

7. Y Y Shao, J Wang, H Wu, J Liu, I A Aksay and Y H

Lin, Graphene based electrochemical sensors and

biosensors: a review, Electroanalysis, 22(2010) 1027-

1036.

8. J Wang, R K Ghosh, S K Das, A survey on sensor

localization, J Control Theory and Applications, 8

(2010), 2-11.

9. A I Buvailo, Y J Xing, J Hines, N Dollahon, E

Borguet, TiO2 / LiCl-based nano-structured thin film

for humidity sensor applications, ACS Appl Mater

Interfaces, 3(2011) 528-533.

10. Y He, T Zhang, W Zheng, R Wang, X W Liu, Y Xia, J

W Zhao, Humidity sensing properties of BaTiO3

nanofiber prepared via electrospinning, Sens Actuat B,

146(2010) 98-102.

11. P M Faia and C S Furtado, Effect of composition on

electrical response to humidity of TiO2: ZnO sensors

investigated by impedance spectroscopy, Sens Actuat

B, 181(2013) 720-729.

12. W C Geng, Q Yuan, X M Jiang, J C Tu, L B Duan, J

W Gu, Q Y Zhang, Humidity sensing mechanism of

mesoporous MgO/KCl-SiO2 composites analyzed by

complex impedance spectra and bode diagrams, Sens

Actuat B, 174(2012) 513-520.

13. P G Su, W C Li, J Y Tseng, C J Ho, Fully transparent

and flexible humidity sensors fabricated by layer-by-

layer self-assembly of thin film of poly (2-acrylamido-

2-methylpropane sulfonate) and its salt complex, Sens

Actuat B, 153(2011) 29-36.

14. Rui Wang, Tong Zhang, Yuan He, Xiaotian Li,

Wangchang Geng, Jinchun Tu, Qing Yuan, Direct-

current and alternating-current analysis of the

humidity-sensing properties of nickel oxide doped

polypyrrole encapsulated in mesoporous silica sba-15,

J Appl Polym Sci, 115(2010) 3474-3480.

15. M V Murugendrappa, M V N Ambika Prasad,

Chemical synthesis, characterization, and direct-

current conductivity studies of polypyrrole/γ-Fe2O3

composites, J Appl Polym Sci, 103(2007) 2797-2801.

16. M V Murugendrappa, Syed Khasim and M V N

Ambika Prasad, Synthesis, characterization and

conductivity studies of polypyrrole–fly ash

composites, Bull Mater Sci, 28(6)(2005) 565-569.

17. Chaluvaraju B V, Sangappa K Ganiger,

Murugendrappa M V, Synthesis, Characterization and

D.C. Conductivity Studies of Polypyrrole/Tantalum

Pentoxide Composites, IJLTEMAS, III (V)(2014) 33-

36.

18. C Basavaraja, EunAe Jo, Bong Seong Kim, Dae Gun

Kim, Do Sung Huh, Electrical conduction mechanism

of polypyrrole-alginate polymer films,

Macromolecular Research, 18(11)(2010) 1037-1044.

19. YaseminArslanUdum, Yavuz Ergun, YucelSahin,

KadirPekmez, Attila Yildiz, Electrochemical synthesis

and characterization of a new soluble conducting

polymer, J Mater Sci, 44(2009) 3148-3155.

20. M Dahlhaus and F Beck, Characterization of

anodically formed polypyrrole/tungsten trioxide

composites, J Appl Electrochemistry, 23(1993) 957-

965.

21. Chaluvaraju B V, Sangappa K.Ganiger, M V

Murugendrappa, Synthesis, characterization and D.C.

conductivity study of polypyrrole/molybdenum

trioxide composites, Polym Sci Ser B, 56(6)(2014)

935-939.

22. S Geetha, D C Trivedi, Synthesis, characterization and

temperature studies on the conductivity of AlCl4- ion

doped polypyrrole, J Mater Sci Mater. Electronics,

16(2005) 329-333.

23. H Nguyen Thi Le, B Garcia, C Deslouis, Q Le Xuan,

Corrosion protection of iron by polystyrenesulfonate-

doped polypyrrole films, J Appl Electrochem,

32(2002) 105-110.

24. Hasim Yilmaz, Huseyin Zengin, Halil Ibrahim Unal,

Synthesis and electro-rheological properties of

polyaniline/silicon dioxide composites, J Mater Sci,

47(2012) 5276-5286.

25. M Ilieva, S Ivanov, V Tsakova, Electrochemical

synthesis and characterizationof TiO2-polyaniline

composite layers, J Appl Electrochem, 38(2008) 63-69.

26. ZhanhuGuo, Koo Shin, Amar B Karki, David P

Young, Richard B Kaner, H Thomas Hahn, Fabrication

and characterization of iron oxide nanoparticlesfilled

polypyrrolenanocomposites, J Nanopart Res, 11(2009)

1441-1452.

27. Pradeep Kumar Upadhyay,Afaq Ahmad, Chemical

synthesis, spectral characterization and stability of

some electrically conducting polymers, Chinese J

Polym Sci, 28(2)(2010) 191-197.

76 Advances in Polymer Science and Technology: An International Journal 2014; 4(4) : 69-76

28. Zh A Boeva, O A Pyshkina and V G Sergeev,

Synthesis of Conducting Polyaniline–Polyanion

Interpolymer Complexes and Study of Their

Composition and Properties, Polym Sci Ser A, 54(8),

(2012), 614-620.

29. Chaluvaraju B V, Sangappa K Ganiger,

Murugendrappa M V, Preparation, Characterization

and Current Studies of Polypyrrole/Tantalum

Pentoxide Composites, Inter J Innov Sci Eng Tech,

1(4)(2014) 141-145.

30. Su Bitao, Min Shixiong, She Shixiong, Tong

Yongchun, BaiJie, Synthesis and characterization of

conductive polyaniline/TiO2composite nanofibers,

Front Chem China, 2(2)(2007) 123-126.

31. Yuvaraj Haldorai, Van Hoa Nguyen, Jae-Jin Shim,

Synthesis of polyaniline/Q-CdSe composite via

ultrasonically assisted dynamic inverse emulsion

polymerization, Colloid Polym Sci, 289(2011) 849-

854.

32. Hasim Yilmaz, Huseyin Zengin, Halil Ibrahim Unal,

Synthesis and electro-rheological properties of

polyaniline/silicon dioxide composites, J Mater Sci,

47(2012) 5276-5286.

33. D P Park, J H Sung, S T Lim, H J Choi, M S Jhon,

Synthesis and characterization of soluble polypyrrole

and polypyrrole/organoclaynanocomposites, J Mater

Sci letters, 22(2003) 1299-1302.

34. Mohammad Sideeq Rather, KowsarMajid, Ravinder

Kumar Wanchoo, Madan Lal Singla, Synthesis,

characterization, and thermal study of polyaniline

composite with the photoadduct of potassium

hexacyanoferrate (II) involving hexamine ligand, J

Therm Anal Calorim, 112(2013) 893-900.

35. Sangappa K Ganiger, Chaluvaraju B V,

Murugendrappa M V, Synthesis, Characterization and

Dielectric Study of Polypyrrole/Sodium Metavanadate

(Ceramic) Composites, Inter J Innov Sci Eng Tech,

3(7) (2014) 130-136.

36. Sangappa K Ganiger, Chaluvaraju B V, Y T Ravikiran,

Murugendrappa M V Synthesis, Characterization and

A.C. Conductivity Study of Polypyrrole/Zinc

Tungstate (Ceramic) Composites, Inter J Innov Sci

Eng Tech, 3(7)(2014) 82-87.

37. Haihua Wang, NaravitLeaukosol, Zhibing He,

Guiqiang Fei, Chuanling Si, Yonghao Ni,

Microstructure, distribution and properties of

conductive polypyrrole/cellulose fiber composites,

Cellulose, 20(2013) 1587-1601.

38. Kirill L Levine, Jude O Iroh, Resistance of the

polypyrrole/polyimide composite by electrochemical

impedance spectroscopy, J Porous Mater, 11(2004) 87-

95.

39. Samrana Kazim, Shahzada Ahmad, Jiri Pfleger, Josef

Plestil and Yogesh M Joshi,Polyaniline–sodium

montmorillonite clay nanocomposites: effect of clay

concentration on thermal, structural and electrical

properties, J Mater Sci, 47(2012) 420-428.

40. D M Jundale, S T Navale, G D Khuspe, D S Dalavi, P

S Patil, V B Patil, Polyaniline–CuO hybrid

nanocomposites: synthesis, structural, morphological,

optical and electrical transport studies, J Mater Sci

Mater Electron, 24(2013) 3526-3535.

41. Dongdong Zhang, Lei Fu, Lei Liao, Nan Liu, Boya

Dai, Chengxiao Zhang, Preparation, characterization,

and application of electrochemically functional

graphenenanocomposites by one-step liquid-phase

exfoliation of natural flake graphite with methylene

blue, Nano Res, 5(12)(2012) 875-887.

42. Yoshio Kobayashi, Satoshi Ishida, Kazuaki Ihara,

Yusuke Yasuda, Toshiaki Morita, Shinji Yamada,

Synthesis of metallic copper nanoparticles coated with

polypyrrole, Colloid Polym Sci, 287(2009) 877-880.

43. Mohammad E Azim-Araghi, Sobhenaz Riyazi,

Synthesis, morphology and optical properties of

nanocomposite thin films based on polypyrrole-bromo-

aluminiumphthalocyanine, J Mater Sci Mater Electron,

24(2013) 4488-4493.

44. Kaushik Mallick, Mike J Witcomb, Mike S Scurrell,

Polyaniline stabilized highly dispersed gold

nanoparticle:an in-situ chemical synthesis route, J

Mater Sci, 41(2006) 6189-6192.

45. Pilli Satyananda Kishore, Balasubramanian

Viswanathan, Thirukkallam Kanthadai Varadarajan,

Synthesis and characterization of metal nanoparticle

embedded conducting polymer–polyoxometalate

composites, Nanoscale Res Lett, 3(2008) 14-20.

46. V S Reddy Channu and Rudolf Holze, Synthesis and

characterization of a polyaniline-modified SnO2

nanocomposite, Ionics, 18(2012) 495-500.

47. S Anoop Kumar, Avanish Pratap Singh, ParveenSaini,

Fehmeeda Khatoon, S Dhawan, Synthesis, charge

transport studies, and microwave shielding behavior of

nanocomposites of polyaniline with Ti-doped γ-

Fe2O3, J Mater Sci, 47(2012) 2461-2471.

48. Geng W, Li N, Li X, Wang R., Tu J, Zhang T, Effect

of polymerization time on the humidity sensing

properties of polypyrrole, Sens Actuat B, 125(2007),

114-119.

49. T Machappa and M V N Ambika Prasad, Humidity

sensing behaviour of polyaniline/magnesium chromate

(MgCrO4) composite, Bull Mater Sci, 35(1)(2012) 75-

81.

50. Narsimha Parvathikar, Shilpa Jain, Syed Khasim, M

Revansiddappa, S V Bhoraskar, M V N Ambika

Prasad, Electrical and humidity sensing properties of

polyaniline/WO3 composites, Sens Actuat B,

114(2006) 599-603.

51. Anirban Chakraborty, Cheng Luo, Multiple conducting

polymer microwire sensors, Microsyst Technol.15

(2009) 1737-1745.

52. Siswoyo, Trio F Nugroho, Zulfikar, Agus Subekti,

Electropolymerisation and characterisation of doped-

polypyrrol as humidity sensor, Indo. J. Chem., 6(2)

(2006) 189-194.

Source of support: Nil; Conflict of interest: None declared