Electron beam induced modifications of polyaniline silver nano-composite films: Electrical conductivity and H2S gas sensing studies

The polyaniline-silver (PANI-Ag) nanocomposite films doped with HCl were prepared on surface modified bi-axially oriented polyethylene teraphthalate (BOPET) by in-situ photo-polymerization. The grown films were modified with high energy (~ 10 MeV) electron beam at different doses (0–100 kGy) in a Linear accelerator. After electron beam exposure the electrical conductivity of the PANI-Ag films was initially found to be enhanced by two orders of magnitude up to 30 kGy of dose and later it falls with increasing dose. Detailed characterizations of the films suggest that enhanced conductivity up to 30 kGy of electron beam dose is due to scissioning as well as additional doping of chlorine in PANI chain, through breaking of covalently bonded chlorine with PANI chain. At higher doses, cross-linking of polymer chains dominates and results in lowering of electrical conductivity. As compared to pristine film, electron beam modified PANI-Ag films exhibit higher sensitivity towards ppm level of H2S gas. The study highlights the effect of electron beam irradiation on PANI-Ag films in terms of electrical conductivity and its inferences on H2S gas sensing.