Preparation of layered B4C with high neutron-shielding properties using graphene as template

In this paper, layered boron carbide (B4C) particles were successfully synthesized by sol-gel-low temperature pyrolysis method using boron acid and glycerin as raw materials with self-made reduced graphene oxide (RGO) as additives. The structure of the sol-gel condensation product was analyzed by FT-IR. The phase, morphology and particle size of the B4C were characterized by XRD, FE-SEM and LPSA. The results showed that boron carbide was rhombic crystal phase, but the surface of the particles was wrinkled and more layered. The B4C powders with uniform morphology and some particle sizes less than 100 nm were prepared with the RGO content of 0.6%. Testing the neutron-shielding properties of the polypropylene-B4C composites suggested that neutron transmittance with the B4C content of 35 wt% was 94.1% lower (from 70.6% to 4.1%) than neat polypropylene, and the total macroscopic absorption cross-section was about 18 times larger (from 0.0857 +/- 0.0031 cm(-1) to 1.5521 +/- 0.0008 cm(-1)). The relative density, fracture toughness and hardness of self-made B4C ceramics (sB(4)C) were higher than the commercially available B4C ceramics (cB(4)C). This study provided a new method for the preparation of B4C powders with excellent neutron absorption properties and good sintering activity.