▎ 摘　　要

In this study, bismuth (III) oxide (Bi2O3) decorated graphene oxide (GO) nanocomposites were employed as novel radioprotective fillers in the epoxy matrix. Decoration of GO with Bi2O3 would transform it as carrier for Bi2O3 particles, thereby enhancing the thermo-mechanical and radiation shielding properties of the epoxy composites through effective filler distribution. Structural and compositional studies confirmed the successful decoration of Bi2O3 on the surface of GO. Thereupon, epoxy composites containing decorated fillers at different loadings (5, 10 and 15 wt%) were synthesized using solution casting technique. The correlation between surface decoration and filler loading was systematically examined as function of thermo-mechanical, viscoelastic and radiation shielding properties of the composites. These nanocomposites displayed good thermal resistance (similar to 450 degrees C), high glass transition temperature (similar to 136 degrees C), elastic modulus (similar to 4.36 GPa) and storage modulus, thereby confirming the improved dispersion and better interfacial adhesion in the composites. The formation of continuous filler network across epoxy matrix formed by decorated fillers significantly improved X-ray and gamma-ray shielding properties of epoxy composites in the wide energy range of medical interest (30 - 1332 keV). Shielding efficiency of these lowly loaded BGO/epoxy composites were comparable with the composites containing Bi2O3 nanoparticles alone and highly loaded microcomposites.