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 (Bi2O3) 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 Bi2O3 into the composites. The 40 wt% Bi2O3 loaded films showed good heat resistance with the peak degradation temperature reaching as high as 251°C. The Bi2O3 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 137Cs, 22Na, 133Ba, and 60Co 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/Bi2O3 composites can be used as soft and biodegradable radiation shields, which may be processed to wearable forms.

Thermal, mechanical and γ‐ray shielding properties of micro‐ and nano‐Ta2O5 loaded DGEBA epoxy resin composites

“…Z eff and N eff of the epoxy composites were calculated by direct method using semi‐empirical relation, following the procedure detailed in Prabhu et al 8 The experimental and theoretical Z eff values for neat epoxy and its micro‐composites showed close agreement (Table S2). The experimental Z eff values for all the epoxy nanocomposites in the energy range 0.356–1.332 MeV are presented in Table S3.…”

“…Density of the samples were measured using BSA224S‐CW Sartorius density determination kit based on Archimedes principle on the samples of 3.5 × 3.5 cm following the procedure detailed in our previous work 6,8 . Thickness of the samples were been measured using a Mitutoyo digital micrometer of accuracy 0.001 mm.…”

“…γ‐Ray transmission measurements were performed at various energies of γ‐rays using four radioactive sources 22 Na (0.511 and 1.274 MeV), 133 Ba (0.356 MeV), 137 Cs (0.662 MeV), and 60 Co (1.173 and 1.332 MeV), all procured from Board of Radiation and Isotope Technology (BRIT), Mumbai, India. The detector was set up in narrow beam geometry and radiation intensity measurements were conducted as detailed in our previous study 8 . After the initial adjustments and calibration of NaI(Tl) detector spectrometer, the experimental procedure was standardized using Aluminium (Al) as standard reference material, as its mass attenuation coefficients (μ/ρ, cm 2 g −1 ) are well determined both experimentally and theoretically.…”

“…Nevertheless, despite these appealing properties, toxicity and relative heaviness of Pb‐based materials necessitate the search for light‐weight and environment‐friendly shielding materials. In this context, radiation shielding materials based on high‐Z metal oxide reinforced polymer matrix composites (PMCs) have captured the attention of radiation researchers and various types of non‐lead PMCs have been explored 1–8 . Investigations on nanostructured polymeric materials have revealed that the large surface‐to‐volume ratio and extremely high surface energy of nanoparticles lead to better matrix‐filler interaction, thus promoting the overall material properties 9 .…”

Properties of Bi2O3/epoxy resin–coated composites for protection against gamma rays

“…Bi 2 O 3 composites can shield a variety of ray sources. The Srilakshmi Prabhu 23 research team 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. The γ-ray attenuation experiments showed that MACs of the composites at various γ-ray energies increased with filler loading.…”