Characteristics of X-ray attenuation in nano-sized bismuth oxide/epoxy-polyvinyl alcohol (PVA) matrix composites

In this study, the X-ray attenuation by 2 mm matrix composites of epoxy-polyvinyl alcohol (PVA) filled with different percentages of bismuth oxide (Bi₂O₃) nanoparticles has been investigated using both mammography and general radiography units. The effect of adding thermosetting polymer (epoxy) over thermoplastic polymer (PVA) on the dispersion of n-Bi₂O₃ within the composite was explained using both secondary and backscattered scanning electron microscopy. The results indicated that the X-ray attenuation by the 2 mm n-Bi₂O₃/epoxy-PVA composites was increased with the increase of n-Bi₂O₃ loading while increasing the tube voltage from 23 to 100 kV. Moreover, X-ray was not detected by the composite filled with n-Bi₂O₃ more than 12 wt% at the tube voltage between 23 and 35 kV. This indicated that the matrix composite with 2 mm thickness filled with ≥ 12 wt% of n-Bi₂O₃ may be used as an X-ray-shielding material for the lower X-ray photon energies operated between 23 and 35 kV by the diagnostic X-ray machine.