Sodium alginate/bismuth (III) oxide composites for γ‐ray shielding applications

Abstract In the present work, we have explored the efficacy of bismuth (III) oxide (Bi 2 O 3 ) loaded, calcium ion cross‐linked solution cast sodium alginate composite films for radioprotective applications. Calcium ion cross‐linking increased the water and chemical resistance, which further improved on introduction of Bi 2 O 3 into the composites. The 40 wt% Bi 2 O 3 loaded films showed good heat resistance with the peak degradation temperature reaching as high as 251°C. The Bi 2 O 3 loaded composites showed enhanced tensile strength (TS) and Youngs modulus (YM). Compared to high‐modulus polymers like epoxy, high‐density polyethylene (HDPE) and poly (vinyl chloride) (PVC), these exhibit relatively greater extent of stretching before breaking. The γ‐ray attenuation experiments showed that mass attenuation coefficients of the composites at various γ‐ray energies increased with filler loading. These composites are effective in shielding γ‐rays from radioactive sources like 137 Cs, 22 Na, 133 Ba, and 60 Co that are widely employed in several medical and industrial applications. The overall enhancement in thermal, mechanical, and radiation shielding characteristics of the composites may be attributed to the uniform distribution of the fillers in alginate matrix. These nontoxic sodium alginate/Bi 2 O 3 composites can be used as soft and biodegradable radiation shields, which may be processed to wearable forms.