Fabrication of Thermal Conductive and Electrically Insulating Polymer Composites with Isotropic Thermal Conductivity by Constructing a Three-dimensional Interconnected Network
Efficient heat removal via thermal management materials has become one of the most critical challenges in the development of modern microelectronic devices. However, the conventional polymer-based thermal conductive composites with randomly distributed filler particles usually yields an undesired value because of the lack of efficient heat transfer pathways. Therefore, constructing a three-dimensional interconnected filler structure is greatly desirable for realizing high thermal conductivity enhancement in composites. Herein, graphene oxide (GO) was used as thermally conductive fillers due to its excellent thermal conductivity and coated it with polydopamine (PDA) to enhance its electric insulation performance. A unique “particle-constructing” method was adopted for fabricating highly ordered three-dimensional GO-based polymer composites, throughout which the GO-PDA formed intact, uniform and well-defined network structure. The composite, even with a very low GO-PDA loading of 0.96 vol %, exhibited both high in-plane (4.13 W m-1 K-1) and through-plane (4.56 W m-1 K-1) thermal conductivity, and also presented excellent electrical insulating properties (>1014 Ω cm). These composites have promising applications in heat dissipation of next-generation portable and collapsible electronic devices.