Polyvinyl alcohol/carbon coated zinc oxide nanocomposites: Electrical, optical, structural and morphological characteristics

Polyvinyl alcohol (PVA) films doped with different concentrations viz., 0.5, 1.0, and 2.0 wt.% of the carbon coated zinc oxide (C-ZnO) nanoparticles were prepared by solution casting method in order to investigate the effect of C-ZnO addition on the electrical, optical, structural and morphological properties of PVA matrix. The electrical properties such as dielectric constant (epsilon'), dielectric loss (epsilon ''), dissipation factor (Tan delta), electrical modulus (M', M '') and AC conductivity (sigma(ac)) of the PVA/C-ZnO nanocomposites have been performed with reference to weight percentage of nanofiller (i.e., 0.5, 1.0, and 2.0 wt%) and frequency (20 Hz to 1 MHz). It is observed that the dielectric constant, dielectric loss, and electrical conductivity gradually decrease with filler concentration. Microstructural property of the nanocomposites is studied by using X-ray diffraction. XRD profiles demonstrated the semi crystalline nature of the composites. SEM photomicrographs of the PVA/C-ZnO nanocomposites reveal the uniform distribution of nanoparticles within the polymer matrix. Differential scanning calorimetry (DSC) thermograms of nanocomposites clearly indicates that the influence of nanofillers on their melting temperature (T-m) is insignificant. (C) 2013 Elsevier B.V. All rights reserved.