Polyaniline based stable humidity sensor operable at room temperature

Abstract

Humidity sensing behavior of polyaniline-tantalum disulfide (PANI/TaS2), a hybrid material/composite studied in the range of relative humidity 10–97%. The material under study was synthesized using in situ chemical polymerization technique with varying wt% of TaS2 in PANI (10, 30 and 50%). XRD pattern of 50 wt% composite revealed amorphous nature of the synthesized hybrid and its FTIR spectrum showed the interaction between PANI and TaS2. TGA established the thermal stability of the composite at the elevated temperatures. Scanning and transmission electron microscopy images evidenced the encapsulated structures of the composite. Porous nature has facilitated and enhanced the humidity sensing properties of the composites. Change in resistance of the material with the increase in relative humidity, exhibited a good linearity in the relative humidity range. PANI/TaS2-50% composite performed maximum sensing response of 97% and recorded a good response and recovery times of 36 and 49 s respectively with a low humidity hysteresis loss. Stable sensing ability of the composite was tested over a period of one month.