Polyaniline-NiO Nanocomposites as Dielectric Materials

Dielectric properties of polyaniline-NiO (PAni-NiO) nanocomposites prepared by in situ chemical oxidative polymerization of aniline with ammonium peroxydisulfate using NiO nanoparticles (NPs) dispersed in aqueous acidic solution was studied using electrochemical impedance spectroscopy (EIS). PAni-NiO nanocomposites were prepared by varying the amount of NiO NPs. The chemical composition, morphology, crytallinity and thermal stability of the composites were studied by using Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS) measurements, scanning electron microscopy, x-ray diffraction (XRD) and thermogravimetric analysis (TGA). The hydrodynamic diameter of NiO NPs determined by DLS measurement was ca. 178 nm. PAni and PAni-NiO nanocomposites showed same thermal degradation pattern but PAni-NiO exhibited greater thermal stability compared to PAni. EIS data showed high dielectric constant and very low dielectric loss for PAni and PAni-NiO nanocomposites. The frequency dependence of dielectric constant, dielectric loss, and loss tangent were analyzed in the frequency range from 0.1 Hz to 10 MHz. Finally, the potential of PAni and PAni-NiO nanocomposites as efficient dielectric materials has been explored. (C) 2018 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of Indian Association of Solid State Chemists and Allied Scientists (ISCAS-2017).