Optical and Color Modification in Polycarbonate/Polybutylene Terephthalate/Zinc sulfide-Nickel Oxide Nanocomposite Films due to Gamma Irradiation

Abstract

Nanocomposites (NC) of amorphous polycarbonate (PC), semicrystalline polybutylene terephthalate (PBT), zinc sulfide (ZnS) and nickel oxide (NiO) nanoparticles (NP) were synthesized. We believe that this study is novel in the area of the effect of γ radiation on such NC. Both the synthesized NiO and ZnS had a nanonature of average particle size 4 and 18 nm, respectively, as indicated from the Rietveld refinement of the XRD records. Samples of the PC-PBT/ZnS-NiO NC films were irradiated with several γ doses (10–140 J/cm2). The resultant outcome of the γ irradiation on the optical behavior of the NC films was studied applying ultraviolet spectroscopy (UVs). Upon raising the dose up to 140 kGy, the direct bandgap decreased from 4.11 to 3.6 eV. The Urbach energy showed an opposite tendency; it increased from 0.61 to 0.95 eV. We attribute this to the dominance of chain crosslinks. Also, the optical dielectric loss (ε″) aided in detecting the nature of the microelectronic transitions. It was found that the PC-PBT/ZnS-NiO NC films had direct allowed transitions. Additionally, the γ induced alterations in the dielectric parameters and optical conductivity were studied. Moreover, the optical color changes between the pristine and the irradiated films were assessed. The pristine NC film was uncolored. It showed significant color alterations when irradiated with γ radiation up to 140 kGy. The induced enhancements in the optical properties suggest that the γ radiation is an effective means that allows the use of PC-PBT/ZnS-NiO NC in optoelectronic devices.