Optical properties of poly (vinyl alcohol)/hydroxypropyl cellulose blendsAuthor(s): Osiris W.Guirguis, Manal T.H.Moselhey
Transparent films of poly (vinyl alcohol)/hydroxypropyl cellulose (PVA/ HPC) blend with different concentrations were prepared by using solutioncast technique. Variations in the group coordination in the IR region were followed. The effects of HPC concentrations on the optical characterizations of the films have been done by analyzing the absorbance, transmittance and reflectance spectra in the spectral region 200Â2500 nm. The study has been extended to include the changes in the optical parameters including the band tail width and band gap energies for the samples. Moreover, the extinction coefficient (k) has been calculated for the investigated films. As obtained by the FTIR and NIR results, the increase in the concentration of HPC with PVA changed the chemical bonds and hence changed the molecular configuration of PVA. The results indicate that the optical band gap was derived from TaucÂs extrapolation and decreases with the HPC contents.