Effect of Kaolin Clay Concentration and Irradiation on the Electronic Transitions of Polyvinyl Alcohol Films

Abstract

Pure and (1 and 3 wt%) kaolin doped PVA films were synthesized by solution casting method, and exposed to 60Co--rays, activity 2µCi for two weeks, The optical characterizations of the films were carried out using UV-Vis transmittance spectrophtometer in the wavelength range 300–900 nm. The results show that in the visible region the transmittance of the films increases as the kaolin concentration increase clearly as comared with the same film before irradiation. The dominant transmittance band of UV region increases after irradiation while the reverse is the case with the reflectance. Also results indicates that PVA films have an indirect band gap that decreased from 3.7 to 3.55 eV as the doping concentration increases to 3wt%. Also the energy band gap of the irradiated films appeared to be decreased from 3.9 eV down to 3.4 eV