Simulation-Guided Synergistic Design of Core-Shell Nanofibers for Lightweight, Moisture-Permeable, and Efficient X/γ-Ray Shielding Membranes

The widespread application of nuclear technology in fields such as energy, medicine, and aerospace has driven the rapid development of high-performance X/γ-ray shielding materials. This work utilized radiation shielding simulation tools, WinXCom and Geant4, to simulate the X/γ-ray shielding performance of heavy-metal/rare-earth metal oxides. Based on the principle of complementary absorption edges, Bi2O3 and Sm2O3 were selected as the optimal shielding components. Three-dimensional models of electrospun membranes were established to systematically investigate the influence of different shielding configurations (single, blended, and core–shell structures) on their X/γ-ray shielding performance. Guided by simulation, coaxial electrospinning technology was employed to load Bi2O3 and Sm2O3 nanoparticles into the shell and core layers of polyacrylonitrile (PAN) nanofibers, respectively, fabricating a hierarchical heteromorphic core–shell nanofibrous membrane (C-SNM). Owing to the complementary absorption characteristics and the multistage shielding attenuation mechanism, a 2 mm thick CSm-SBiNM (70 wt % filler loading) achieved an X-ray shielding efficiency of 52.54% at 80 kV, equivalent to 0.25 mm Pb, while its density was 0.492 g cm–3, merely 4.34% of the Pb plate (11.344 g cm–3). Without weight increase, component optimization and configuration design enhanced shielding performance of the CSm-SBiNM by about 4%, compared to a uniaxial nanofibrous membrane (UNM) with a disordered blended structure. Furthermore, the CSm-SBiNM exhibited a water vapor transmission rate of 6.582 kg m–2 d–1 and PM2.5 filtration efficiency exceeding 99.960%. The C-SNM combines efficient, broad-spectrum radiation protection with lightweight and moisture-permeable properties, overcoming the limitations of traditional rubber/plastic-based materials in this regard, and laying a foundation for next-generation radiation protection materials.