Synthesis and dielectric investigations of bismuth sulfide particles filled PVA: Polypyrrole core-shell nanocomposites

High dielectric composites of bismuth sulfide (Bi2S3) filled in poly (vinyl alcohol) (PVA)/polypyrrole (PPy) blend were prepared. Fourier Transform Infrared Spectroscopic analysis infers the encapsulation of Bi2S3 particles by PVA: PPy matrix. The thermal activation is estimated using Coats and Redfern equation from thermogravimetric analysis results. SEM micrographs revealed that Bi2S3 filled PVA:PPy blend composite films possess smooth surface and homogeneous dispersion of particles. The frequency dependence of dielectric constant, loss tangent and electric modulus were analyzed. The characteristic relaxation times for dielectric loss within the composites are calculated. The AC conductivity is maximum for 8 wt% of bismuth sulfide particles. The dielectric parameters and AC conductivity are temperature dependent. The dielectric response parameter s follows the correlated barrier hopping model and accordingly effective barrier height (Wm) of the composite for 8 wt% Bi2S3 filled PVA: PPy are determined.