Role of Surfactant in Polyaniline/Polypyrrole Heterojunction for Liquefied Petroleum Gas Sensor Application

Vishal K. Pandit1,3

Nafeesa M. Soudagar1

Mohanrao V. Mandke2

Sneha S. Joshi1,Email

1Department of Physics, Rajaram College, Vidyanagar, Kolhapur, 416004 India.
2Departments of Physics, Faculty of Sciences, National Defence Academy, Khadakwasla, Pune, 411023 India.
3Departments of Physics, Rayat Shiksan Santha’s Dada Patil Mahavidyalaya, Karjat, Ahmednagar, 414402 India.

Abstract

Polymer-based sensors are very important due to their wide use in hazardous gas sensing applications. Various polymers, like polyaniline (PANI), polypyrrole (PPy), and polythiophene, are used in sensor applications. In the present study, the effect of surfactant on the sensitivity of polymer-based heterojunction is studied at room temperature. In the heterojunction, a film of PPy having a thickness of 4 μm is deposited by galvanostatic mode on a stainless steel substrate in the absence or presence of surfactants like cetyltrimethylammonium bromide (CTAB), TX-100, and sodium dodecyl sulfate (SDS). Then, to fabricate heterojunction, PANI film is deposited with the help of layer-by-layer chemical bath deposition on the pre-deposited PPy films. A layer-by-layer process was used to attain a maximum thickness of 0.72 μm for PANI films. The heterojunctions of PANI and PPy are fabricated and named PANI/PPy-NS, PANI/PPy-CTAB, PANI/PPy-TX, and PANI/PPy-SDS. The heterojunction was exposed in a liquefied petroleum gas (LPG) environment of different concentrations to study LPG sensing performance at room temperature and relative humidity (RH) 46%. The PANI/PPy-SDS heterojunction shows maximum sensitivity of about 63% for a 1040 ppm concentration of LPG. The average response time and recovery time are about 80 seconds and 500 seconds, respectively.

Role of Surfactant in Polyaniline/Polypyrrole Heterojunction for Liquefied Petroleum Gas Sensor Application