Exploration of the gamma-ray shielding capabilities of tungsten oxide and chromium-infused silicone rubber composites

Gamma rays are highly energetic type of ionizing radiation important in medical diagnostics, which requires effective protective measures. Polymers reinforced with appropriate fillers can offer excellent radiation shielding properties comparable to conventional materials. This study investigates the gamma radiation shielding efficiency of silicone rubber reinforced with tungsten oxide (WO3) and chromium (Cr). Composites with fixed 30 phr WO3 and varying Cr concentrations (10-70 phr) were fabricated and characterized. Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (FESEM/EDX) confirmed uniform filler dispersion, while FTIR showed no significant chemical changes. X-ray diffraction (XRD) analysis revealed average crystallite sizes of 11-32 nm (Scherrer's formula) and 16-39 nm (Williamson-Hall plot). The mechanical properties were explored using a Universal Testing Machine (UTM), revealing that an increase in filler content correlated with enhanced tensile strength and hardness. Gamma attenuation studies (using Cs-137 and Ba-133 sources) revealed the excellent efficiency of the composite with 30 phr WO3 and 50 phr Cr (3WO5C) with Mass Attenuation Coefficients (MAC) increasing from 1.45, 0.202, and 0.103 cm2/g to 1.57, 0.258, and 0.129 cm2/g, and half-value layer (HVL) thickness decreasing from 0.356, 2.551, and 6.722 cm to 0.269, 1.642, and 5.366 cm, for gamma energies 80, 356 and 662 keV respectively. Critically, these composites are significantly lighter than lead, offering improved shielding performance at a reduced weight.