Influence of combined annealing and gamma irradiation treatment on the structure and optical properties of polystyrene thin films

Abstract

After annealing and irradiation, the chemical and optical properties of polymers are investigated. Before being exposed to gamma rays in a source chamber filled with cobalt-60, polystyrene films were prepared and annealed for an hour at 85 °C. Fourier transform infrared spectroscopy (FTIR) was used to examine the chemical characteristics of the polystyrene sheets following treatment. Using UV-Vis to measure transmittance and absorption spectra, the optical energy gaps of thin films were investigated and evaluated. The findings demonstrated that increasing the annealing temperature and thickness improves the extinction coefficient while reducing the energy gap to 1.3 eV.  The value of the imaginary dielectric is less than that of the real dielectric. This outcome shows that the substance has both a refractive index and a response to incident light, as well as a refractive index of 2.5 at 400.

KEY WORDS: Polystyrene, Optical properties, FTIR, Annealing, Irradiation

Bull. Chem. Soc. Ethiop. 2026, 40(1), 173-182.                                                      

DOI: https://dx.doi.org/10.4314/bcse.v40i1.14