Bismuth Oxide Nanoparticle-Enhanced Poly(methyl methacrylate) Composites for I-131 Radiation Shielding: A Combined Simulation and Experimental Investigation.

This study investigates the development of advanced radiation shielding materials incorporating bismuth oxide (BiO) nanoparticles (NPs) into polymethyl methacrylate (PMMA) composites, comparing efficacy against I-131 gamma radiation. The NPs exhibit a 1.53-fold reduction in z-average diameter and a significantly higher surface area than BiO, ensuring superior dispersion and structural uniformity within the PMMA matrix. These characteristics, validated through SEM, EDX, and XRD analyses, contribute to enhanced gamma radiation attenuation, leveraging the high atomic number and density of BiO. Mechanical evaluations reveal that increasing BiO-NPs concentrations enhances ductility but reduces tensile strength, likely due to nanoparticle agglomeration and stress concentration. Radiation shielding performance, assessed using XCOM and Phy-X/PSD simulations, demonstrates a direct correlation between BiO content and attenuation efficiency. Notably, composites with 75% BiO content exhibit attenuation properties comparable to, or exceeding, those of PbO, achieving superior shielding efficacy at reduced thicknesses across various photon interaction mechanisms. These findings position BiO NPs-enhanced PMMA composites as promising lightweight high-performance alternatives to lead-based shields. By addressing toxicity and environmental concerns associated with lead, this work emphasizes the potential of high-Z nanomaterials in advancing radiation protection applications. This study highlights a transformative approach to designing safer and more efficient shielding solutions, contributing to the next generation of radiation protection materials.