The formation of nanoparticles of boron carbide on the basis of an alkoxide, boron and of a polyvinyl alcohol

摘要

PROBLEM TO BE SOLVED: To provide a process for producing a high-purity particle having a particle size of nm scale in high yield as boron carbide for radiation protection.SOLUTION: A process for producing a boron carbide nanoparticle comprising (i) allowing boric acid, boron oxide, or B(OR)type boric ester to interact with 1 to 2 molar equivalents of at least one Cto Cpolyol(s) under a condition which favors formation of boron alkoxide powder, (ii) allowing the resulting boron alkoxide powder to interact with an effective amount of one or more polyvinyl alcohol(s) (PVA) in an aqueous medium under a condition which favors formation of cross-linked PVA gel, wherein the PVA has been completely hydrolysed and has molar mass of 10,000 to 80,000 g mol, and (iii) thermally and oxidatively decomposing the formed cross-linked gel under a condition, including air flowing at 500 to 1200°C, favorably 600 to 1000°C, more favorably 800°C, which favors formation of a CBnanoparticle.SELECTED DRAWING: None