M K Alqadi, M S Abu Ennab, H M Al-Khateeb, F Y Alzoubi, S A E Abzakh
PVA/PEG (80:20) blend films containing B4C, Bi2O3, and hybrid B4C/Bi2O3 fillers were prepared by solution casting and characterized to establish relationships among their structural, thermal, optical, electrical, morphological, and radiation-interaction properties. XRD analysis showed that filler incorporation reduced the crystallinity of the PVA/PEG matrix from 82.38% to 72.15%, 69.73%, and 57.26% for the Bi2O3-, B4C-, and hybrid-filled films, respectively. The 20 wt% B4C formulation exhibited the highest thermal stability T50% = 380 °C and the most spatially uniform electrical response, whereas the hybrid composition exhibited the lowest optical band gap (3.32 eV) and greatest structural disorder. Gamma-ray attenuation was evaluated computationally using GAMOS 7.0 and Phy-X/PSD over 0.0595-1.50 MeV. The Bi2O3-containing composition exhibited the strongest calculated low-energy photon attenuation; at 0.0595 MeV, GAMOS yielded an LAC of 1.613 cm-1, corresponding to an HVL of 0.430 cm. GAMOS and Phy-X results differed by approximately 0.7-5.1% at representative energies, providing a computational cross-check. Thermal-neutron calculations using the NIST/NCNR approach showed that the B4C-containing composition had the highest macroscopic absorption cross section (9.158 cm-1), the lowest transmission (42.28% at 0.060 cm), and the smallest 1/e penetration depth (0.070 cm), whereas differences in the calculated fast-neutron removal cross section were modest. These results indicate complementary roles of Bi2O3 in low-energy photon attenuation and B4C in thermal-neutron absorption. The shielding results are computational and require experimental validation before practical implementation.