Establishing Bi2O3 - B2O3 - based glasses for multifunctional shielding: Elucidating the interplay of physical, structural, and mechanical properties with PCA-based trend analysis.

BACKGROUND

Developing eco-friendly, high-performance radiation shielding materials is now a priority, driven by needs in medical imaging, nuclear technology, and aerospace safety.

METHODS

In this study, a series of theoretically designed Bi2O3-B2O3-SiO2-Al2O3-ZnO glasses (GL-1 to GL-4) were systematically analyzed to elucidate how compositional tuning influences their structural compactness, mechanical properties, and dual-mode (γ, n) attenuation efficiency. A combined analytical-computational framework, integrating the Makishima-Mackenzie (M-M) mechanical model with MCNPX transport simulations, was employed to establish quantitative links between bonding topology and radiation interaction behavior across gamma photon energies of 0.015-15 MeV and neutron energies of 0.5-10 MeV.

RESULTS

Increasing Bi2O3 content was associated with a monotonic rise in bulk density (5.82-6.32 g cm-3), accompanied by reductions in theoretical Vt and Gt per unit volume, consistent with a compositional transition toward a more polarizable Bi-O-dominated network. This structural evolution is predicted to strengthen gamma photon interaction probabilities but reduce elastic stiffness, as evidenced by the systematic decline in Yb, Kb, S, and L obtained from the M-M model. PC1, accounting for 99.4% of the variance, suggests a dominant compositional trend in which Bi2O3 enrichment is associated with increasing density and Vm and decreasing Vt, Gt, and predicted elastic moduli, and a modest increase in model-predicted hardness within the limited compositional range studied. In addition, PC2 accounts for only 0.6% of the total variance and therefore represents only minor secondary variations among the glass compositions. Monte Carlo simulations indicate that γ-ray attenuation improves with Bi enrichment: GL-4 shows the highest simulated MAC and lowest HVL, suggesting lower HVL than RS-360 and ordinary concrete within the P-E and C-S regimes under the simulated conditions. Conversely, the simulated neutron shielding efficiency decreases with rising Bi2O3 concentration.

CONCLUSIONS

The synergistic integration of structural-mechanical modeling and Monte Carlo transport analysis suggests that Bi2O3 - B2O3 - based glasses may represent promising lead-free, composition-tunable candidates for multifunctional shielding applications in mixed γ-n radiation environments. All mechanical and shielding results are derived from theoretical models (M-M) and MCNPX Monte Carlo simulations; experimental validation is recommended for future work. The findings are based on computational predictions only, and the small sample set (n = 4) limits the generalizability of the PCA trends.