Jelly-Inspired Construction of the Three-Dimensional Interconnected BN Network for Lightweight, Thermally Conductive, and Electrically Insulating Rubber Composites

The improvement of modern electronics, which is constantly getting faster, has raised higher requirements for thermally conductive and electrically insulating thermal interface materials. Developing a facile and universal processing method with high thermal conductivity enhancement efficiency is in pressing need to keep up with this trend. Herein, we propose a cost-effective foaming route to construct the three-dimensional (3D) interconnected boron nitride (BN) network. Owing to the inspiration of jelly, curdlan, an esculent polysaccharide with a unique gelling behavior, is employed as a gelling agent to stabilize and immobilize the bubble-templated network. The results show that the thermal conductivity of the polydimethylsiloxane composites containing this 3D BN thermal conductive network reaches 1.58 W/(m·K) at a low BN content of 25.4 wt %. Moreover, the density of this composite is ∼1.27 g/cm3, which is 40-50% lower than that of commercial silicone pad products with a thermal conductivity of 1.5 W/(m·K). Meanwhile, the composites are also highly electrically insulating with a volume electrical resistivity over 1015 ω·cm. The superior performance of the as-obtained composites demonstrates a promising prospect to tackle thermal management problems in modern electronics.