Nickel oxide @ polyindole/phenothiazine blend nanocomposites: preparation, characterization, thermal, electrical properties and gas sensing applications

This paper describes the preparation, characterization and electrical properties of polyindole (PIN)/phenothiazine (PTZ) blend nanocomposite with different contents of nickel oxide (NiO) nanoparticles. Ultraviolet-Visible spectroscopy and Fourier transform infrared spectroscopic characterizations were carried out to investigate the extent of chemical interactions between PIN/PTZ blend and NiO nanoparticles. Morphological studies carried out using scanning electron microscopy and transmission electron microscopy showed the formation of globular composite particles with a size in 15-25 nm range. X-ray diffraction study of the resultant composites reveals the distribution of sharp crystalline peak of NiO in the blend. Thermo-gravimetric results confirmed that the rate of degradation of the composite was lower as compared to the pure polymer blend and the thermal stability of the blend increases with the loading of nanoparticles. An investigation of the electrical properties of the prepared nanocomposites revealed that AC conductivity, dielectric constant and dielectric loss of composite increased in proportion to the increase in NiO loading. Current-voltage measurements (I-V curve) showed that the PIN/PTZ/NiO composites have much higher electrical conductivity than pure polymer blend. The gas sensing measurement for PIN/PTZ blend with different contents of NiO nanoparticles toward ammonia gas were investigated.