Variation in tungsten(vi) oxide particle size for enhancing the radiation shielding ability of silicone rubber composites

In this work, the attenuation properties of silicon rubber (SR) composites reinforced by both micro- and nano-sized Tungsten trioxide (WO3) particles are studied. Different SR composites with different combinations of micro-WO3 and nano-WO3 have been prepared. The main composite, SR-(WO3)60m (40% SR containing 60% micro-WO3), and other compositions were prepared by replacing percentages of microparticles with nanoparticles of WO3. The linear attenuation coefficient for these composites was measured in the range of 0.06–1.333 MeV. The existence of micro and nanoparticles together may result in enhanced interactions with incoming photons, leading to greater shielding. In other words, micro-WO3 and nano-WO3 have various sizes and surface areas. At 0.06 MeV, we notice a distinguished decrease in the half value layer (HVL) from SR-W60m to SR-W60n. The sequence of reducing HVL values (SR-(WO3)60m > SR-(WO3)60n > SR-(WO3)40m20n > SR-(WO3)20m40n > SR-(WO3)30m30n) suggest that the inclusion of both micro- and nano-WO3 contributes to more efficient radiation shielding compared to the reference material. The radiation shielding efficiency (RSE) for SR-(WO3)30m30n at 0.662 MeV is 38.40%. This means that if a beam of photons with energy of 0.662 MeV interacts with SR-W40m20n sample, only 38.12% of the photons are successfully absorbed or stopped, whereas the remaining 61.88% can pass through this sample. At 1.333 MeV, the lowest RSE is observed, which means that the prepared composites have weak attenuation ability at higher energy levels.