Synthesis of Polypyrrole Using Ferric Chloride (FeCl3) as Oxidant Together with Some Dopants for Use in Gas Sensors
Hemant K. Chitte, Ganesh N. Shinde, Narendra V. Bhat, Vasant E. Walunj
DOI: 10.4236/jst.2011.12007   PDF   HTML     11,955 Downloads   27,599 Views   Citations


Polypyrrole (Ppy) was synthesized using Ferric Chloride (FeCl3) as oxidant. The ratio of monomer to oxidant was 1:2.4. The polymerization was carried out at 5C. Attempts were made to increase the electrical conduc-tivity by using various dopants viz. Lithium per Chlorate (LiClO4), para-Toluene Sulfonate (p-TS) and Nap-thalene Sulfonic acid (NSA). The materials were characterized using FTIR, X-Ray diffraction and SEM. The electrical conductivity was measured by two probe method and was found to be in the range of 10-3 to 10-2 S/cm. Thin films of these preparations were casted on the interdigited electrodes to study the detection of gases such as ammonia and LPG. It was found that for the pure Ppy and one doped with LiClO4, when ammonia gas was allowed to flow in, there was a sudden increase in the current, which decreased rapidly when gas was stopped. This behavior is in contradiction to that observed in earlier investigations where Ppy was prepared by electrochemical method. However when Ppy doped with p-TS and NSA were used, the trend was reversed. Similarly it was noted that for pure Ppy and one doped with LiClO4, p-TS and NSA there was an increase in the current when LPG gas was brought in. However the response to LPG was somewhat low as compared ammonia gas.

Share and Cite:

H. Chitte, G. Shinde, N. Bhat and V. Walunj, "Synthesis of Polypyrrole Using Ferric Chloride (FeCl3) as Oxidant Together with Some Dopants for Use in Gas Sensors," Journal of Sensor Technology, Vol. 1 No. 2, 2011, pp. 47-56. doi: 10.4236/jst.2011.12007.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] S. C. Hernandez, D. Chaudhari, W. Chen, N. Myung and A. Mulchandani, “Single Polypyrrole Nanowire Ammonia Gas sensor,” InterScience, Vol. 19, No. 19-20, 2007, pp. 2125-2130.
[2] S. Cosnier, C. Gondran, R. Wessel, F. T. Montforts and M. Wedel. “A Poly (Pyrrole – Cobalt (II) Deuteroporphyrin) Electrode for the Potentiometric Determination of Nitrite,” Sensors, Vol. 3, 2003, pp. 213-222. doi:10.3390/s30700213
[3] M. F. Mabrook, C. Pearson and M. C. Petty, “Inkjet – Printed Polypyrrole Thin Films for Vapor Sensing,” Vol. 115, 2006, pp. 547-557.
[4] R. A. Bissell, K. C. Persaud and P. Travers, “The Influence of Non-Specific Molecular Partitioning of Analytes on the Electrical Response of Conducting Organic Polymer Gas Sensors,” Physical Chemistry Chemical Physics, Vol. 4, No. 14, 2002, pp. 3482-3490. doi:10.1039/b201292h
[5] H. Bai and G. Shi, “Gas Sensors on Conducting Polymers,” Sensors, Vol. 7, 2007, pp. 267-307. doi:10.3390/s7030267
[6] L. A. Mashat, H. D. Tran, W. Wlodarski, R. B. Kaner and K. K. Zadeh, “Conductometric Hydrogen gas Sensors Based on Polypyrrole Nanofibers,” Vol. 4, 2008, pp. 365-370.
[7] A. Joshi, S. A. Gangal, N. Padma, D. K. Aswal and S. K. Gupta, “Gas Sensing Properties of Polypyrrole Thin Films,” 2008.
[8] S. Hosein and A. A. Entezami, “Polypyrrole Based Toxic Gas Sensors by Mass and Conductivity Measurements,” Iranian Polymer Journal, Vol. 8, 1999, pp. 205-213.
[9] H. Yoon, M, Chang and J. Jang, “Sensing Behavior of Polypyrrole Nano Tubes Prepared in Reverse Micromulsions: Effects of Tranducers Size and Transduction Mechanism,” Journal of Physical Chemistry B, Vol. 110 2006, pp. 14074-14077. doi:10.1021/jp061423b
[10] V. Saxena, S. Choudhary, S. C. Gadkari, S. K. Gupta and J. V. Yakhmi, “Room Temperature Operated Ammonia Gas Sensor Using Polycarbazole Langumuir-Blodgett film,” Sensors and Actuators B: Chemical, Vol. 107, No. 1, 2005, pp. 277-282. doi:10.1016/j.snb.2004.10.011
[11] L. Jiang, H. K. Jun, Y. S. Hoh, J. O. Lim, D. D. Lee and J. S. Huh, “Sensing Characteristics of Polypyrrole – Poly (Vinyl Alcohol) Methanol Sensors Prepared by in Situ Vapour State Polymerization,” Sensors and Actuators B: Chimical, Vol. 105, No. 2, 2005, pp. 132-137. doi:10.1016/j.snb.2003.12.077
[12] R. Ansari, “Polypyrrole Conducting Electro Active Polymers: Synthesis and Stability Studies,” E-Journal of Chemistry, Vol. 3, No. 13, 2006, pp. 186-201.
[13] H. Kato, O. Nishikwa, T. Matsui, S. Honma and H. Kokado, “Fourier Transform Infrared Spectroscopy Study of Conducting Polymer Polypyrrole Higher Order Structure of Electrochemically Synthesized Film,” The Journal of Physical Chemistry, Vol. 95, No. 15, 1991, pp. 6014- 6016. doi:10.1021/j100168a055
[14] N. V. Bhat, A. P. Gadre and V. A. Bambole, “Structural, Mechanical and Electrical Properties of Electro polymerized Polypyrrole Composite Films,” Journal of Applied Polymer Science, Vol. 80, No. 13, 2001, pp. 2511-2517, doi:10.1002/app.1359
[15] T. K. Vishnuvardhan, V. R. Kulkarni, C. Basavaraja and S. C. Raghavendra, “Synthesis, Characterization and A. C. Conductivity of Polypyrrole/Y2O3 Composites,” Material Science, Vol. 29, No. 1, 2006, pp. 77-83.
[16] H. Eisazadeh, “Studying the Characteristics of Polypyrrole and Its Composites,” World Journal of Chemistry, Vol. 2, No. 2, 2007, pp. 67-74
[17] R. Turcu, M. Brie, G. Leising, V. Tosa, A. Mihut, A. Niko and A. Bot, “FTIR Reflectance Studies of Electrochemically Prepared Polypyrrole Films,” Applied Physics A, Vol. 67, 1998, pp. 283-287. doi:10.1007/s003390050772
[18] S. A. Waghule, S. M. Yenorkar, S. S. Yawale and S. P. Yawale, “SnO2/PPy Screen – Printed Multilayer CO2 Gas Sensor,” Sensors and Transducers, Vol. 79, 2007, pp. 1180-1185

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.