Structural properties, conductivity, dielectric behaviour and gas sensing application of polyaniline/phenothiazine/copper sulphide blend nanocomposites

Abstract

This paper reports the investigation on structural, morphological, thermal, gas sensing, electrical conductivity and dielectric properties of polyaniline (PANI)/phenothiazine (PTZ) blend filled with different contents of copper sulphide (CuS) nanoparticles. The prepared nanocomposites were analyzed through Fourier-transform infrared (FTIR), UV–vis spectroscopy, x-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and impedance studies. The presence of CuS in the blend led to some changes in the position of peaks in the FTIR and UV spectrum. XRD displayed a significant increase in crystallinity and intensity of the composite with increasing the amount of CuS nanoparticles. A granular morphology of the composite as compared to pure blend was confirmed by SEM and TEM images. The TGA results indicated that the onset degradation temperature of PANI/PTZ blend nanocomposites was shifted towards higher temperature in the presence of CuS nanoparticles. The dielectric constant and dielectric loss tangent (tan δ) decreased, whereas the AC conductivity increased with increasing frequencies. The dielectric properties, AC and DC conductivity of polymer blend increased with increase in CuS loading and showed maximum electrical properties at 10 wt% loading. The ammonia gas sensing performance of the blend nanocomposites was significantly enhanced by the addition of CuS nanoparticles. These results suggest that PANI/PTZ/CuS nanocomposites with improved electrical conductivities, gas sensing and dielectric properties seem to be promising materials for designing electrical or nano-electronic devices.