Effect of gamma-irradiation on the colorimetric properties of epoxy-resin films: Potential use in dosimetric application

The present paper reports the results of the colorimetric study of gamma-irradiated epoxy-resin films. Epoxy-resin samples were irradiated by gamma-rays with doses varying from 1 to 50 kGy. Color changes of epoxy-resin were observed and studied by the measurements of the variation of the L∗, a∗, b∗ as function of dose and post-irradiation time. Where L∗ is a measure of the magnitude of brightness from black to white, parameter a∗ describe the relative amounts of red and green, and parameter b∗ describes the relative amounts of yellow and blue color. Color changes (ΔE) were also calculated. They indicated a marked dependence of the absorbed doses showing the optical activation of the color centers. It was found that color changes (ΔE) due to absorbed dose increase from 6 to 50. Color change showed a low variability which did not exceed 3% for the measurements carried out between 1 and 72 h. The obtained results revealed that epoxy-resin films can be used as a new routine dosimeter or irradiation indicator in dose range 1–50 kGy.