Bi-PMMA composite materials and their shielding capability for low energy gamma rays

Abstract

The composite materials filled with different metal particles could provide the potential to meet the proper advantages for gamma radiation protection in both medicine and industry. In this paper, a new, fast, simple and low costing synthesis of bismuth powders using aluminum foil is presented as a gamma-shielding alternative to lead and cement base materials. The synthesized powders were characterized by XRD and FE-SEM. Flexible Bi-PMMA composites having 40, 50 and 60 wt% of bismuth were subsequently prepared and their gamma-shielding properties were investigated. The attenuation constants of the composites such as linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), half-value layer (HVL), and mean free path (MFP) were then obtained using the relevant measured values at available energies of Am-241, Cs-137 and Co-60 gamma sources. Gamma-shielding properties of the composites (at each gamma energy) were improved with the weight percentage increase of the bismuth powder in the polymer matrix but on the other hand the shielding capability reduced with the increase of the gamma energy. The HVL value for the sample containing 60 wt % of bismuth powder at a gamma energy level of 59.5 keV was found to be 0.072 cm. This HVL value was very close to that of lead, 0.068 cm, at the same energy. Moreover, the developed composites had the following features: easy and rapid fabrication process, nontoxic nature, lightweight, flexible, environment-friendly, and cost-effective.