Nano‐W Dispersed Gamma Radiation Shielding Materials

We present a nano-W dispersed polymer composite whose gamma attenuation is greatly enhanced. In situ pulverization and simultaneous encapsulation of polyethylene (PE) onto the nano-W particles was successfully performed by ball milling. Adhesive encapsulation of PE was observed by means of interstitial diffusion of atomic W at the boundary using transmission electron microscope. Prepared nano-W/PE particles were dispersed into ethylene-propylene-based polymer mixture using melt mixing. Attenuation of gammas for the nano-W composites was enhanced up to approximate to 75% for Ba-133 (approximate to 0.3MeV) compared to the micro-W composites, while it decreases as the photon energy increases. MCNP simulation also shows similar gamma attenuation behaviors.