Micromorphology tunable Eu2O3 submicron spheres reinforced boron-containing HDPE composites for neutron and gamma-ray complex radiation shielding.

In this research, a series of Eu 2 O 3 /B 4 C/HDPE composites containing micromorphology tunable Eu 2 O 3 submicron spheres as fillers are prepared for shielding neutron and gamma ray. The influence of microstructure of Eu 2 O 3 fillers on thermal stability, mechanical, and radiation shielding properties of composites are studied in detail. The growth process of Eu 2 O 3 precursor (Eu(OH)CO 3) follows the LaMer and Ostwald ripening mechanism. The FESEM reveal that the microstructure of synthesized Eu 2 O 3 is submicron sphere and the particle size decreases with addition of urea content in the reactant solution. HRTEM and SEAD images reveal that the overall crystal morphology of the Eu 2 O 3 fillers is polycrystalline. BET analyses reveal that the hysteresis loops of nitrogen adsorption-desorption isotherms changes from Type H1 to H3 after Eu 2 O 3 fillers are ball-milled, which is attributed to the suppression of nanoparticle agglomeration by ball milling. The FESEM images and EDS mapping of the fracture surfaces of the composites reveal that Eu 2 O 3 fillers are evenly distributed in the HDPE matrix. It is revealed that under the condition that the agglomeration of the nanoparticles is effectively suppressed, the higher BET-specific surface area and smaller size of Eu 2 O 3 fillers are conducive to the various properties of the composites. The superior composite containing Eu 2 O 3 (R = 1:30)/B 4 C/HDPE has a 99.1 % neutron shielding rate with 15 cm thickness under a 252Cf neutron source and a 73.1 % gamma shielding rate with 15 cm thickness under a 137Cs gamma source. [ABSTRACT FROM AUTHOR]