The influence of ZnO nanoparticles on the structural, optical and dielectric properties of Polyvinyl alcohol films

Abstract

Polyvinyl alcohol/Zinc oxide (PVA/ZnO) nanocomposite films with various weight percentages of ZnO nanoparticles (0 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%) were prepared by solution casting method. The structural, optical and morphological properties of the synthesized samples were characterized by X-ray diffraction (XRD), UV–Visible spectroscopy, Fourier transform Infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). X-ray diffraction studies confirms the formation of PVA/ZnO nanocomposites. From the UV–vis absorbance spectra, the band gap energy of the samples was calculated and its value decreases with increasing the wt% of ZnO into the PVA matrix. The transmittance of the nanocomposites in the visible region is decreased with increasing the concentration of ZnO into the PVA matrix and completely blocked in the UV region. These behaviours suggests that the nanocomposite materials could be used as UV shielding materials. The FTIR analysis indicates physical interaction between hydroxyl group of PVA and ZnO. SEM shows the dispersion of ZnO on the surface of PVA matrix. The dielectric properties and AC conductivity measurement in the frequency range 100 Hz to 1 MHz reveals the maximum dielectric constant at PVA/5 wt% ZnO nanocomposite.