Tailoring the optical and dielectric properties of PVC/CuO nanocomposites

The solvent casting method has been applied to prepare PVC/CuO nanocomposite films with CuO ratios (0, 2.5, 5.0, 10.0 and 15.0 wt%). X-ray diffraction (XRD), Fourier transform infrared spectroscopy, optical absorption and dielectric experimental analysis are applied to these nanocomposite films. The CuO nanoparticles have been prepared by using sol-gel method. XRD pattern analysis revealed the formation of CuO (30 nm) single-phase with monoclinic structure and space group C-2/c and the amorphous structure of polyvinyl chloride (PVC) matrix. Energy-dispersive X-ray data revealed the increase in CuO content, and scanning electron microscopy morphology analysis approved the dispersion of CuO nanoparticles on the PVC film surface. The optical absorption increased with CuO content, while the transmission decreased. Both direct and indirect energy gaps decrease, while the Urbach energy increases as CuO content increases. The real dielectric permittivity enhanced as the concentration of CuO increased and the imaginary permittivity showed single relaxation at high frequency. The estimated values of both static and high-frequency dielectric constant increased as CuO percentage increases. The presence of CuO causes increase in the loss tangent values for the PVC/CuO polymer films.