Enhancing neutron shielding and radiation modification properties of silicone rubber through the addition of silica encapsulated boron nitride nanosheets

Abstract With the rapid development of nuclear energy, neutron shielding materials are increasingly attracting the attention of researchers. In this work, the hydrolysis properties of tetraethyl orthosilicate (TEOS) are used to grow a SiO 2 shell in situ on the surface of boron nitride (BN) to obtain the radiation enhanced additive mBN. It is added to silicone rubber (SR) to form the mBN/SR neutron shielding composite material and is modified by γ‐rays. We investigate the effects of different amounts of tetraethyl silicate on the morphology, mechanical properties, thermal stability, and neutron shielding properties of mBN and its composites. The tensile strength of mBN/SR is reached 3.80 MPa. mBN/SR also has good thermal neutron shielding properties, with a thermal neutron shielding rate and a linear attenuation coefficient of 75.89% and 7.11 cm −1 , respectively. The macroscopic properties and microstructural changes of mBN/SR after irradiation with different atmospheres and doses of γ‐rays are systematically investigated. The results show that the mechanical properties of mBN/SR are best when irradiated in a vacuum at 150 k Gray, and its tensile strength is increased by 16.89%. The vacuum prevents oxygen from participating in the irradiation cross‐linking reaction, and the crosslinking network formed at this dose is the strongest, with the least oxidized groups. In addition, the residual organic siloxane on the surface of mBN can form a cross‐linked structure with the silicone rubber chain during irradiation. This research has provided new ideas for preparing high‐performance neutron shielding silicone rubber. Highlights The mBN was synthesized by in situ growth of a SiO₂ shell on the BN surface. The SiO₂ shell thickness of mBN could be adjusted by the TEOS concentration. The best γ‐ray modification of silicone rubber was irradiated at 150 kGy in vacuum. The mBN enhanced the crosslinking reaction of silicone rubber in radiation.