Sm 2 O 3 micron plates/B 4 C/HDPE composites containing high specific surface area fillers for neutron and gamma-ray complex radiation shielding

In this study, a series of Sm 2 O 3 micron plates/B 4 C/HDPE composites composed of synthesized Sm 2 O 3 fillers (Sm 2 O 3 micron plates) are prepared for shielding neutron and gamma radiation. The influence of micromorphology of Sm 2 O 3 fillers on neutron and gamma radiation shielding properties of composites is investigated in detail. The XRD pattern reveals that the phase of synthetic Sm 2 O 3 is cubic crystal systems, body-centered cubic lattices, and its space group is Ia 3 (206). SEM images and BET analyses reveal that the micromorphology of synthesized Sm 2 O 3 is micron plates. The BET-specific surface area of the Sm 2 O 3 fillers is increased with addition of urea content. The differential scanning calorimetry (DSC) curves reveal that Sm 2 O 3 fillers increase the melting temperature of the composites, which is up to 138.6 degrees C. The thermogravimetric analysis (TGA) results reveal that the initial thermal degradation temperatures of the composites are all above 440 degrees C. The neutron and gamma radiation shielding tests show that Sm 2 O 3 fillers with high BET-specific surface area (8.20 m 2 /g) and uniform size improve the neutron and gamma shielding rate of composites. A superior composite containing 10 wt% Sm 2 O 3 (R = 1:25, R value represents the molar ratio of rare earth elements to urea)/20 wt% B 4 C/70 wt% HDPE has a neutron radiation shielding rate of 98.7% with a thickness of 15 cm under the 252 Cf neutron source and a gamma radiation shielding rate of 72.1% with a thickness of 15 cm under 137 Cs gamma source. And these lead-free and environment-friendly composites can be widely used in the neutron and gamma complex radiation fields.