Gamma Irradiation Effects on Optical Properties and FTIR Spectrum of Methyl Orange Doped Polyvinyl Alcohol Films


Methyl orange (MO) dye doped PolyVinylAlcohol (PVA) polymer film has been prepared by casting method. Absorption and transmission spectra have recorded in order to determine the type of electronic transitions and find the value of the optical energy gap before and after Gamma radiation. The results indicated to expect indirect transition and the value of energy gap decreased from 5.16 eV for unirradiated pure PVA film to 4.98 eV after exposed to 17.8KGy Gamma radiation. While energy gap for unirradiated (10ml) MO doped PVA film is about 5.18eV and decreased to 5eV after 17.8KGy Gamma radiation. In addition, the same diminishing in energy gap were occurred for 25ml MO doped PVA film. The radiation effect on the refractive index and extinction coefficient for all samples were studied. Also, FTIR spectra was recorded for all samples with radiation of Gamma ray; there is inconsiderable effect of radiation on bonds.