Enhancing the Optical Properties of Polyvinyl Alcohol by Blending It with Polyethylene Glycol
Rania Mohammed Ahmed, Ali Ibrahim, Elbadrawy Elsaid
Abstract
In the present research work a solution casting technique was utilized to fabricate various blends of polyvinyl alcohol (PVA)/polyethylene glycol (PEG). Embedding PEG in PVA resulted in obvious shifts in the absorption edge which points to a decrease in the energy gap values based on PEG content. Loss of the photon energy was a consequence of increasing the extinction coefficient at high wavelengths. The PEG content increased the refractive index of the PVA in the produced PVA/PEG blends. The direct and indirect energy gap values were decreased whereas the Urbach energy values were increased with increasing the PEG content. The exact electron transition which is responsible for the absorption process was determined successfully based on the complex optical dielectric functions. In addition, some other optical parameters were estimated to more understand fully the effect of embedding the PEG in the PVA. The Fourier transform infra red spectroscopy was used to determine the characteristic functional groups of both the PVA and the PEG.