Optical Transmission and Color Investigation of the Effect of Gamma Radiation on Polyvinyl Alcohol/Polyethylene Glycol/Polyvinyl Pyrrolidone Blend Films

In the current paper we prepared a blend film containing polyvinyl alcohol (PVA), polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) using a solution casting technique. Samples from the prepared PVA/PEG/PVP film were irradiated with gamma radiation doses (10 - 80 kGy). The resultant effects of the gamma ray irradiation on the optical and color properties of the prepared films were investigated using UV-vis spectroscopy and the International Commission on Illumination (CIE) color changes technique. When the gamma dose was increased to 80 kGy, the direct optical band gap (E-g) decreased from 3.28 to 3.22 eV. We attribute this decrease to the dominance of crosslinking that damaged the ordered structure and thus increased the amorphous regions. Moreover, the values of E-g, obtained from epsilon '' vs. energy plots, were close to those values obtained using Tauc's relation, indicating that the blend films exhibited a direct allowed transition. Finally, the color changes between the pristine and irradiated films were estimated. The pristine PVA/PEG/PVP blend film exhibited significant color differences.