Optically Transparent Polymer-Tungstophosphoric Acid Composite Films with High Refractive Index

Recently high refractive materials have been developed because of their potential uses in optical applications such as optoelectronic device, plastic lenses, fuel cell, etc. Organic-inorganic hybrid materials have been... [ view full abstract ]

Recently high refractive materials have been developed because of their potential uses in optical applications such as optoelectronic device, plastic lenses, fuel cell, etc. Organic-inorganic hybrid materials have been focusing on creating it. Heteropoly acids (HPAs) are a multifunctional material and have interesting properties, including the solubility in aqueous and nonaqueous solutions, the different charges, shapes and sizes, which can induce to novel materials. In this study, a transparent, colorless and high refractive polymer composited with HPAs has been developed. Polyvinyl alcohol (PVA) and poly(methyl methacrylate) (PMMA) were used in this propose. Tungstophosphoric acid (PWA), which is a member of HPAs, was used in this study. The polymer composite films were simply prepared from mixing polymer and PWA then casted on a glass. The schematic illustration exhibits the image of polymer-PWA composite. The optical and structural properties of the obtained composite films were investigated using ultraviolet-visible spectroscopy, a prism coupler and thermogravimetric analyses. The results presented by the both of polymer-PWA (90 wt.%) provided high transparency (90%T) in the visible region (Fig. 1a) and high refractive index (n =1.70). In addition, TiO2 nanoparticles were also used to prepare and study the composite film. Unfortunately, the polymer-TiO2 gave low transparency and turbid film as shown in Fig. 1 (b,d). Therefore, we believe that the optimal combination for creating a colorless and highly refractive polymer films are PVA and PMMA by using PWA 90 wt.%. The observed polymer composited films with PWA should be developed to high refractive and transparent materials for the optical applications.