Enhancement of the Dielectric Properties of Polyvinyl Alcohol by Adding TiO2Nanoparticles

High dielectric constant nanocomposite polymer films based polyvinyl alcohol (PVA) with different weight ratios of nanoparticles (NPs) TiO 2 (1.0, 2.5, 5.0, and 10) are prepared by the casting method. The structure of TiO 2 NPs is studied using TEM and XRD spectra, where the FTIR spectra show a strong interaction between PVA and TiO 2 NPs. The addition of TiO 2 NPs to the composites improves their mechanical properties. The dielectric parameters and AC conductivity are explored in the 10 Hz to 10 7 Hz frequency range at different temperatures. PVA composite films filled with 5.0 wt% TiO 2 NPs exhibit the highest dielectric constant ( ε′ ) reaching up to 26 at 25 °C and 100 Hz. The origins of the enhanced dielectric properties are investigated using theoretical predictions of the effective ε′ of composites. The activation energy of a dielectric relaxation process is computed. As the temperature rises, the relaxation time lengthens slightly. A conduction mechanism is described based on thermally activated electron hops at the Fermi edge.