Efficiency of flexible shielding materials against gamma rays: Silicon rubber with different sizes of Bi ₂ O ₃ and SnO

Abstract In this study, the efficiency of flexible composites consisting of viscous silicone rubber as matrix and micro- and nanoparticles of Bi 2 O 3 and SnO 2 as fillers was investigated. Four composites with a matrix/filler at 50:50 were prepared. The four samples are the liquid silicone rubber (LSR) materials with micro-Bi 2 O 3 , micro-Bi 2 O 3 , and nano-SnO, nano-Bi 2 O 3 , and nano-SnO, and both nano-Bi 2 O 3 and nano-SnO are labeled as LSR-Micro, LSR-Micro/Nano, LSR-Nano/Micro, and LSR-Nano/Nano, respectively. The morphologies and the homogeny of the nanoparticles and the prepared composites were checked by scanning electron microscopy. The efficiency of shielding characteristics was investigated experimentally by the narrow-beam technique using a lead collimator, different gamma-point sources, and a semiconductor detector. The results showed that at both energies, the composites that contain a combination of micro- and nanoparticles have higher linear attenuation coefficient (LAC) values than the composites with only micro- or nanoparticles. For example, at 0.060 MeV, the LACs are 5.592, 6.391, 6.412, and 6.202 cm −1 for LSR-Micro, LSR-Micro/Nano, LSR-Nano/Micro, and LSR-Nano/Nano, respectively, while at 0.662 MeV, they are, respectively, 0.185, 0.204, 0.210, and 0.199 cm −1 . The prepared composites were compared with commercial lead aprons of different thicknesses, and the results demonstrated the efficiency of the prepared flexible composites against gamma radiation, in addition to their lightweight and environmental safety.