Engineering Zeolite Frameworks for Radiation Shielding: Interplay between Topological Density and Structural Compactness for Optimized Attenuation

This study systematically evaluates the radiation shielding performance of silicon-based zeolite frameworks (FAU, LTA, CHA, AST, MOR, FER, RHO) by correlating their topological density (TD), structural compactness, and compositional parameters with photon attenuation metrics. The RHO framework emerges as the most effective shield, achieving exceptional MAC (47.914 cm²/g) and LAC (148.064 cm⁻¹) values at 15 keV, attributed to its high density (ρ = 3.09 g/cm³), balanced topological parameters (TD₁₀ = 641, TD = 0.533), and moderate accessible volume (20.63%). Its superior performance is further underscored by the highest effective atomic number (Z_eff = 40.82 at 15 keV), reflecting optimized photon interaction efficiency. In contrast, the AST framework, with low density (ρ = 0.217 g/cm³), excessive porosity (TD = 0.625, zero accessible volume), and poor atomic packing, exhibits the weakest attenuation (MAC = 6.488 cm²/g, LAC = 1.409 cm⁻¹). The interplay of topological parameters reveals that intermediate TD values (e.g., RHO, FAU) enhance shielding by balancing atomic packing and density, while high porosity (e.g., AST) diminishes performance. Notably, RHO maintains its advantage at higher energies (e.g., 5.0 MeV: MAC = 0.034 cm²/g, LAC = 0.106 cm⁻¹, Z_eff = 17.03), whereas FAU’s moderate density (ρ = 0.388 g/cm³) and accessible volume (27.42%) make it suitable for multifunctional applications. These insights underscore the importance of harmonizing topological compactness, accessible volume, and density in designing zeolite-based shields, with RHO serving as a benchmark for high-performance radiation protection in nuclear and medical applications.