Optical Study on PVA/PEG Blend Doped with Nano-Silica

Transparent films of polyvinyl alcohol/polyethylene glycol (PVA/PEG) blend loaded with different nano-silica (SiO 2 ) content were prepared by using solution casting. The effect of SiO 2 nanoparticle loading on the optical properties of selected PVA/PEG blend ratio is studied in the spectral region 200–700 nm. The present study monitors the changes in the optical dispersion parameters such as band tail width, extinction coefficient, refractive index, and optical dielectric constant calculated as a function of nano-silica content. The results revealed that the obtained optical parameters were strongly affected by the SiO 2 content in the blend films. Also, Cauchy model is used to fit the wavelength dependence of the refractive index of the composites. In addition, thermogravimetric analysis indicates the increase of thermal stability of the composites with respect to pure blend. The Coats and Redfern model is used to calculate activation energies for decomposition.