Electrical and humidity sensing properties of synthesized hydrophosphoric acid doped polyaniline

H3PO4 doped polyaniline was synthesized by a single‐step chemical polymerization method using ammonium persulfate as an oxidizing agent. The material characterization was done by SEM, UV–vis spectroscopy and thermogravimetric analysis (TGA). The pellets of the synthesized material were used to study the electrical properties, using a four‐probe method. The room temperature electrical conductivity is found to be 0.2201 S/cm. The electrical resistance in response to the varying humid environment (ranging between 20 and 100% RH) is recorded to evaluate the sensitivity of the H3PO4 polyaniline samples toward humidity. The resistance of the samples is found to vary by three orders of magnitude for 20–100% RH and is found to decrease with increasing humidity. The response and recovery time are observed to be 12–14 and 26–30 sec, respectively.