Structural and Optical Properties of Polyvinyl Alcohol/Zinc Oxide Nanocomposites

Herein, pristine poly(vinyl alcohol) (PVA) and PVA-zinc oxide (ZnO) nanocomposite thin films are prepared by solution casting method with different wt% of ZnO (0.1, 0.2, 0.3, 0.5 wt%) nanoparticles with PVA polymer matrix. The addition of ZnO in a PVA matrix induces decrease in the transparency of films. The structural characteristics of prepared thin films are analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopy. XRD confirms the presence of ZnO structure and beta-phase in the synthesized films. The average crystallite size of the prepared thin films were determined by Scherer's equation. XRD result shows increase in percentage crystallinity of the films. Vibrational modes and functional groups present in pristine PVA and PVA/ZnO thin films are identified by FT-IR and Raman spectroscopy. FTIR analysis shows the characteristics bands, which corresponds to O-H and Zn-O bands present in the films. Raman spectra of pristine PVA and PVA/ZnO films are reported. Optical characteristics of synthesized pristine PVA and PVA/ZnO nanocomposite thin films are studied by UV-vis spectroscopy. Optical constants like absorption edge, direct bandgap, optical dielectric constant, loss, and optical conductivity were estimated, and optical dispersion parameters are calculated by single oscillator model.