Mechanochemistry of hexagonal boron nitride. 2. Reactivity upon interaction with water

Abstract

Mechanical activation makes boron nitride chemically reactive with respect to water. The fact of the reaction proceeding, which is accompanied by a change in the structure of boron nitride, is confirmed by the data of IR spectroscopy, X-ray diffraction, transmission electron microscopy, differential thermal analysis, adsorption, and gravimetry. It is established that the most defective amorphous part of the material is primarily hydrolyzed. The reaction takes place at room temperature, with the conversion increasing to values of higher than 50% with the dose of mechanical energy supplied during the mechanical activation. In addition to ammonia, hydrolysis gives rise to the formation of ammonium pentaboride, NH₄B₅O₆(OH)₄ · 2H₂O. After the reaction products are removed, residual boron nitride, which is dried at T ≤ 100°C, crystallizes to form nanosized rods.