The effect WO 3 nanoparticles on the structural and morphological properties of epoxy composites for gamma shielding application

Abstract In this study, the effect of incorporating tungsten trioxide nanoparticles (WO 3 -NPs) at varying weight percentages (5–25 wt%) into an epoxy resin matrix was investigated for gamma radiation shielding applications. Structural characterization was examined by x-ray diffraction (XRD), revealing the amorphous nature of pure epoxy and the emergence of crystalline monoclinic WO 3 peaks, which increased in intensity with increasing filler content. Surface morphology was examined by field emission scanning electron microscopy (FESEM), showing a homogeneous distribution of WO 3 -NPs at lower concentrations, while higher concentrations led to agglomeration and reappearance of nano-cracks. The Gamma attenuation performance was evaluated using Am-241(60 keV), Cs-137 (662 keV), and Ra-226 (1120 keV) sources. The results showed that the linear attenuation coefficient (LAC) increased significantly with WO 3 loading across all gamma energies. The shielding efficiency for a 0.5 cm-thick sample improved from 6.47%, 4.65%, and 2.22% for pure epoxy to 41.26%, 25.16%, and 12.03%, respectively. These results demonstrated the enhanced shielding capability of the composites, especially at lower gamma energies. The current results exhibited competitive attenuation with previous studies at lower filler concentrations, highlighting the potential of WO 3 as an effective, lead-free alternative for radiation shielding applications.