Influence of Ta2O5 nanoparticles on the polyvinyl alcohol films’ structure and optical parameters for UV shielding applications

Our current objective is to develop a pioneering system utilizing polyvinyl alcohol (PVA) as a host matrix for the Ta₂O₅ nanoparticles for shielding applications. The PVA-Ta₂O₅ films were obtained via casting and characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), and a polarized optical microscope. XRD and FTIR analyses showed the incorporation of Ta₂O₅ nanoparticles in the PVA matrix and the change in the polymeric film structure. The optical bandgap energy of the PVA was affected by the inclusion of Ta₂O₅ nanoparticles and was investigated through Tauc's relation using the absorption data recorded from the ultraviolet–visible spectrophotometer. The direct/indirect bandgaps decreased from 5.37/4.51 eV to 3.52/2.24 eV for PVA undoped and PVA after doping with 5.7 % Ta₂O₅, respectively. Moreover, the refractive index of the polymer film increased from 1.9148 for pure PVA to 2.3347 after 5 % Ta₂O₅ was added to the PVA. Adding Ta₂O₅ nanoparticles to the PVA film improves PVA's optical parameters, qualifying it for use in many optical applications.