an8b01047_si_001.pdf (399.62 kB)

One-Step in Situ Ball Milling Synthesis of Polymer-Functionalized Few-Layered Boron Nitride and Its Application in High Thermally Conductive Cellulose Composites

Download (399.62 kB)
journal contribution
posted on 14.08.2018, 00:00 by Cuiping Yu, Qichong Zhang, Jun Zhang, Renjie Geng, Wei Tian, Xiaodong Fan, Yagang Yao
The chemically inert surface and strong ionic bonds make exfoliation and functionalization of hexagonal boron nitride (h-BN) difficult. This inevitably increases the interface thermal resistance and hinders phonon transfer. Herein, polydopamine (PDA)-coated exfoliated h-BN, denoted as exfoliated h-BN@PDA, was prepared by a one-step ball milling route. During the ball milling process, dopamine self-polymerized into PDA on the surface of the exfoliated h-BN@PDA in an alkaline aqueous solution. The coated PDA contents were estimated to be about 3 wt %. Meanwhile, exfoliation of h-BN occurred due to the hydrolysis of h-BN in water and the shear force introduced by ball milling. The results reveal that the exfoliated h-BN generally composed of <20 layers. The resulting exfoliated h-BN@PDA was further added to cellulose nanocrystal (CNC) and improved thermal conductivity up to 40 W m–1 K–1 with 94 wt % h-BN. By controlling the feed ratio, exfoliated h-BN@PDA/CNC composites with different h-BN contents were fabricated. The corresponding thermal conductivity increased with increasing h-BN contents. A facile, highly efficient, and moderate route to prepare modified few-layered two-dimensional layered materials was provided. These composites have great potential in thermal management applications.