Exploring the Optical Behavior of Gamma Ray Irradiated Polycarbonate/Poly(Methyl Methacrylate)/Polyethylene Oxide Blend Films

Abstract

Polycarbonate/poly(methyl methacrylate)/polyethylene oxide (PC/PMMA/PEO) blends were formed using a casting technique. Samples from the prepared PC/PMMA/PEO films were irradiated with γ ray doses ranging from 20 to 180 kGy. UV-vis spectroscopy was used to explore the resulting effects of the γ ray irradiation on the optical properties of the prepared films. The impact of the γ ray irradiation on the light absorbance, transmission, refractive index, extinction coefficient, dielectric constant and optical conductivity of the PC/PMMA/PEO blend films was examined. The absorbance of the blend films increased as it was irradiated with the γ ray doses up to 180 kGy, the maximum dose used. The increase in absorbance was associated with a decrease in the direct bandgap from 4.52 to 4.20 eV, and an increase of Urbach energy from 0.37 to 0.87 eV. Also, we used the optical dielectric loss (ε”) to detect the type of microelectronic transition for the PC/PMMA/PEO blend films, which was found to be a direct allowed transition. Moreover, the optical color changes between the pristine and the irradiated films were assessed using the International Commission on Illumination color differences technique. The pristine film was uncolored. It showed significant color alterations when irradiated with γ radiation up to 180 kGy. The induced enhancement in the optical properties indicated that the γ radiation is a useful tool that would allow the application of the resulting PC/PMMA/PEO blend films in optoelectronic devices.