Room temperature humidity sensing behaviour of silver decorated polyaniline composite

The present work is an investigation of humidity sensing response of silver decorated polyaniline composite prepared by in situ chemical oxidative interfacial polymerization using ammonium peroxydisulfate as an oxidant at 0 °C-4 °C. The structural characterization of the samples was examined using FT-IR, XRD, SEM and TEM techniques. The characteristic stretching frequencies in FT-IR spectra are notably shifted towards lower frequency side indicating van der Waals forces of interaction between the interfacial polyaniline (PANI) chain and the silver particles. The surface morphology of the synthesized composite show that, the silver particles appears to be embedded in the PANI matrix. Humidity response measurements of thin free-standing films were carried out by using Mextech-DT-615 instrument at 25 °C. It is observed that there is a decrease in the resistance of the composite with the increase in relative humidity, quick response and recovery times, their sensing performance stability; all revealed their potential candidature for the humidity sensing applications. © 2019 IOP Publishing Ltd.