Study on the Optical Properties of PVA /PEG Doped with Sodium Fluoride Salt Polymer Blend Electrolyte Films

Polymers when doped with metal salts give complexes which are useful for development of the advanced high-energy electrochemical devices such as high-energy density rechargeable batteries and energy storage devices. The materials used in this work were procured from Sigma Aldrich company having 99.99% purity and are used without any further purification throughout the research experiment. In the present work, solid polymer blend electrolyte films of PVA (Polyvinyl Alcohol) and PEG (Polyethylene Glycol) doped with different weight percent ratios of NaF (Sodium Fluoride) were prepared by the solution casting method. The effect of NaF concentration on the optical properties of (PVA/PVP-NaF) films has been investigated using a UV-Vis Spectrophotometer in the wavelength range (200-800 nm). The optical constants like absorption spectra, transmission spectra, refractive index, extinction coefficient, real and imaginary parts of the dielectric constant and optical band gaps are investigated. It was found that the optical energy band gap is decreased upon the increase in NaF salt concentration which is contrary to the variation of conductance. The experimental results show that the optical constants showed clear changes with increasing the doping concentrations. The optical constants such as extinction coefficient, refractive index, and real and imaginary dielectric constants are found to depend on the NaF concentration in the PVA/PEG blended polymer matrix. These physical aspects will contribute to producing a new material that might potentially be used as an alternative or substitute material for many other applications.