Exfoliation of hexagonal boron nitride using wet-rotating disc milling

A wet-rotating disc milling was used as a novel method to investigate the exfoliation of laminated hexagonal boron nitride (h-BN) particles. The sedimentation test after the milling showed that the relative packing density of h-BN particles treated by the wet-rotating disc milling was much low compared to non-milled h-BN particles. Also, the particle size distributions showed that the particle size of exfoliated h-BN particle was relatively as similar as the initial particle size. Furthermore, SEM images of wet-rotating disc milled h-BN particles showed that the decrease of h-BN thickness was affected to the relative packing density after sedimentation test. The average aspect ratio of prepared h-BN particles was increased 1.8 times as compared to pristine h-BN particles. The wet-rotating disc milling process led to exfoliation of laminated h-BN particles without reducing the particle size and destroying the crystal structure. Moreover, the relative packing density of exfoliated h-BN particles was affected to rotation speed, number of pass, and distance between two rotation discs. Therefore, it was found that the exfoliation of laminated h-BN particles effectively was progressed by wet-rotating disc milling. (C)2015 The Ceramic Society of Japan. All rights reserved.