Proton exchange assisted charge conduction and enhanced humidity sensitivity of polyvinyl pyrrolidone incorporated polyaniline

Polyaniline has been prepared by a chemical in situ polymerization process using ammonium peroxodisulphate (APS) as the polymerizing agent. The prepared polyaniline was mixed with polyvinyl pyrrolidone (PVP) at different weight percentages in aqueous medium and painted on paper substrates. The electrically conductive flexible polyvinyl pyrrolidone incorporated polyaniline (P-PVP) samples show superior resistive sensitivity with varying relative humidity of the environment at room temperature. Addition of polyvinyl pyrrolidone into polyaniline powder reduced the electrical conductivity of the composites which in turn increased the sensitivity towards relative humidity. Electrical charge conduction processes in the prepared P-PVP samples were studied to analyze the resistive humidity sensing properties. The systematic and notable response of resistive behavior of the samples with humidity variation has been the key inspiration for studying the humidity sensing behavior of the prepared samples. The effect of compositional variation with different polyvinyl pyrrolidone content has also been studied. The experimental observations indicate that the P-PVP system can be a potential candidate as an active electronic material for designing lightweight, and portable humidity sensor on flexible substrate, adaptable to various technologies. The reported sensor system having deposited on a paper substrate has become cost-effective, and biodegradable, and thus it can be employed as a use-and-throw type humidity sensor.