A Spectroscopic Study on the Polymer Colour Transition for Indicating the Exposure to Ionizing Radiation

Abstract

This paper presents results from a series of experiments in which two combinations of polymer-dye film were exposed to ionizing radiation (electron beam). These experiments were performed for the purpose of investigating the possibility of polyethylene (PE) and polyvinyl chloride (PVC) with and without the addition of malachite green (MG) dye for radiation indication in the form of colour transition. MG dye was also inspected whether it has experienced the photodarkening from the exposure to ionizing radiation. The experiments were carried out using samples in the form of film. From this study, it was proven that the polymers and dye do not work alone to give the change. Halogen-containing polymer was found positive in stimulating the acid-sensitive dye for the transition of colour. The colour transition of the combination of PVC/MG without pH adjustment was consistently increasing with irradiation level. The transition is observed even at 100 kGy of the radiation exposure. Samples with the addition of basic solution have a rapid change in terms of colour but the limit of sensitivity was decreased to only 20 kGy of radiation exposure.