Effect of gamma radiation on the spectroscopic properties of Bromocresol green-polyvinyl chloride film

Bromocresol Green (BCG) - Polyvinyl chloride (PVC) film was prepared by dispersing the dye in the polymer matrix in a suitable solvent medium in the presence of an organic base and then solvent casting the formulation in the form of transparent colored film. Preliminary studies through UV-Vis Spectroscopic measurements show that the prepared PVC - dye films was sensitive to gamma radiation almost linearly in the dose range upto 8 kGy range. This spectroscopic change becomes visually distinguishable from 4 kGy onwards until 8 kGy where it finally changes color from green to yellow, beyond which no significant optical change was observed. The gamma response of the film could be tailored by varying the concentration of the pH sensitive dye and the organic base. (author)