Multimodal performance evaluation and machine learning-optimized prediction of flexible, mixed-field radiation shielding using GO/MXene-scaffolded PVC ternary nanocomposites

This study presents a comprehensive multimodal evaluation of flexible Polyvinyl Chloride (PVC) ternary nanocomposites (TNCs) reinforced with Boron Carbide (B ₄ C), Bismuth Oxide (Bi ₂ O ₃ ), and a Graphene Oxide (GO) scaffold supported by MXene (Ti ₃ C ₂ Tx) sheets. Fabricated via solution casting, the TNC series (TNC-1 to TNC-4, with up to 25 wt% Bi ₂ O ₃ ) aims to resolve the critical trade-offs between high mixed-field radiation attenuation, thermal stability, and mechanical embrittlement typically associated with heavy-element-loaded polymers. Structural and morphological analyses (XRD, SEM-EDX) validated the formation of a stable, two-dimensional GO/MXene network that effectively optimized particle dispersion and prevented Bi2O3 agglomeration even at maximum loading. Robust interfacial chemical bonding between the polymer matrix and the functionalized scaffold, evidenced by significant shifts in FTIR spectra, translated into a 27°C elevation in the initial TGA degradation temperature and an 11.3°C shift in the DSC glass transition temperature, confirming restricted segmental chain dynamics. Most significantly, this engineered interface mitigated high-Z loading embrittlement; while TNC-4 achieved an impressive four-fold reduction in both the Half-Value Layer (HVL) and Tenth-Value Layer (TVL) at 0.662 MeV and systematic suppression of gamma-ray buildup factors (EBF and EABF) via efficient scattering capture in the Compton region, it simultaneously doubled the Young’s Modulus and maintained substantial tensile toughness and flexibility. Finally, meticulous MCNP6 version 6.2 simulations and an optimized predictive Machine Learning framework (Random Forest Regression) yielded robust correlation statistical, with R ² values exceeding 0.9985 and a relative deviation below 3% for all targets, establishing this ternary system as a systematic optimization for demanding multifunctional shielding designs in mixed-field environments.