Humidity Sensing Behavior of Polyaniline / Strontium Arsenate Composites

The response of conducting Polyaniline (PANI) / Ceramic (Sr3(AsO4)2) composites system to air moisture environment is studied. The conducting PANI and its composites are prepared by in situ polymerization technique. These prepared samples were characterized by XRD, FTIR & SEM, which confirms crystallinity, composite formation and porosity of the samples. The temperature dependent conductivity measurement shows the thermally activated behavior, where the conductivity increases with increase in temperature. The decrease in electrical resistance with change in relative humidity (RH) over broad range (ranging between 20 to 95 %) is due to the increase in surface electrical conductivity resulting from moisture absorption and due to capillary condensation of water causing increase in conductivity within the sensing materials

Sensitivity and Selectivity Studies on Polyaniline / Molybdenum Trioxide Composites to Liquid Petroleum Gas

The LPG sensing material polyaniline / molybdenum oxide composites were prepared by insitu polymerization In situ polymerization with 10, 20, 30, 40 and 50wt % of MoO3 in PANI and were characterized by SEM and infrared spectroscopy (FTIR). The variation of sensitivity with Parts Per Million by volume (PPM)v and time respectively is observed, when the pressed pellets of the polymer were exposed to the LPG. The selectivity studies of these composites shows remarkable sensitivity for 10, 40 & 50 wt%, after its exposure to LPG, oxyacetylene, ethanol and H2S gas. Maximum sensitivity is found to be 78 % and 50 % for LPG and oxyacetylene gas respectively. The response time has been estimated to be 6.66 and 13.33 minutes for LPG. The results obtained for these composites are of scientific and technological interest