Thermal, Optical, and Color Modification in Makrofol VLG 7-1 Nuclear Track Detector Due to Gamma Irradiation

Abstract

Makrofol VLG 7-1 is a sort of Makrofol (bisphenol-A polycarbonate) nuclear track detector. We believe that the current study is the first one that deals with the effect of γ-ray irradiation on Makrofol VLG 7-1. Samples of Makrofol films were treated with various γ-ray dosages (20–140 kGy). The resultant outcome of the γ-ray irradiation on the thermal and optical characteristics of the Makrofol samples were explored applying thermogravimetric analysis (TGA) and ultraviolet spectroscopy (UVs). The degradation temperature, activation energy of thermal decomposition, optical band gap, refractive index, Urbach energy, and optical dielectric parameters were characterized and interpreted based on the γ-ray dosage. The optical bandgap dropped from 4.26 to 4.14 eV for a γ-ray dosage of 140 kGy, accompanied with a rise in both Urbach energy and thermostability of the samples. We attribute this to the dominance of crosslinking. Additionally, the color differences between the pristine and the irradiated samples were characterized. The pristine Makrofol was uncolored. It exhibited noteworthy color changes during the γ-ray treatment, as the color intensity reached a value greater than 5. This is an acceptable match in commercial reproduction on printing presses.