Room temperature alcohol sensors based on PANi/MWCNT composite thin film

Alcohol gas sensors based on composite thin film of polyaniline (PANi) with multiwall carbon nanotube (MWCNT) have been prepared using spin coating technique. PANi was synthesized by chemical oxidative polymerization of aniline using ammonium persulfate in hydrochloric (HCl) medium. The PANi was doped with MWCNT in presence of NMP by solution mixing method and spun on aluminum interdigitated electrodes. The as-deposited thin film was converted into conducting form using HCl doping process. The formation and morphology of PANi/MWCNT composite thin films were analyzed with UV/VIS spectroscopy and scanning electron microscope. Their electrical and gas response characteristic was measured under vapors of methanol, ethanol and acetone at room temperature. The results demonstrate that PANi/MWCNT composite thin film exhibit the highest sensitivity to methanol and the lowest to acetone. Their responses show good recovery time and high selectivity for alcohol vapors.