Synthesis of novel conducting triblock copolymer poly(thiophene-co-pyrrole-co-aniline) by chemical oxidative polymerization method for gas sensor application

Abstract

The conducting triblock copolymer P(Th-co-Py-co-Ani) of thiophene (Th), pyrrole (Py), and aniline (Ani) has been synthesized by chemical oxidative polymerization method using anhydrous iron (III) chloride (FeCl3) as an oxidizing agent in presence of acetonitrile solvent at 0–8°C. Characterizations of the synthesized copolymer were performed by Attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction analysis (PXRD), UV-Vis spectroscopy, elemental analysis (CHNS), Thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM). Notably, UV-Vis spectroscopy revealed that triblock copolymers exhibit highly conjugated conducting polymer backbone, essential for its electrical conductivity and suitability for various applications. The prepared P(Th-co-Py-co-Ani) material was investigated for the gas sensing property of several gases such as ammonia, acetone, carbon monoxide, ethanol and methane. The gas sensing study revealed that P(Th-co-Py-co-Ani) demonstrates promising gas sensing capabilities, particularly at room temperature.