Influence of Ta2O5 on polyaniline surface for liquid petroleum gas sensing applications

Abstract

Purpose - The purpose of this paper is to study the sensitivity and selectivity properties of polyaniline/tantalum pentoxide (PANI/Ta2O5) composite to liquid petroleum gas (LPG). Design/methodology/approach - Polyaniline/tantalum pentaoxide (PANI/Ta2O5) composites were synthesized by in situ chemical polymerization method using ammonium persulphate as an oxidizing agent. This is the novel polymerization process for the direct synthesis of emeraldine salt phase of the polymer. The composites were characterized by FTIR, XRD and SEM. Temperature dependence conductivity of the composites shows thermally activated behaviour. Sensitivity and selectivity of the composites are studied. Findings - The PANI/Ta2O5 composites of 20 wt% and 30 wt% are showing maximum change in resistance against time when compared to pure PANI and other polyaniline composites when exposed to LPG. The 20 wt % composites show maximum sensitivity of 83% to LPG. The selectivity studies reveals that LPG could be sensed better when compared to oxyacetylene and other test gases. Practical implications - Selectivity studies have been carried out and the sensor proved to be better than metal oxides sensors. Social implications - The sensing material is of low cost. Originality/value - To the best of the authors' knowledge, studies on Ta2O5-based gas sensor have not been reported previously.