Highly thermally conductive and electrical insulating epoxy-based composites containing oriented ternary carbon/graphene/MgO hybrid network

Graphene promises considerable application potentials in improving the thermal conductivity of polymeric composites due to its superior intrinsic thermal conductivity. However, the simple incorporation of graphene in polymeric composites usually fails to meet the requirements for simultaneously high thermal conductivity and electrical insulation. Herein, an epoxy-based composite with excellent thermal conductivity and electrical insulation has been produced by introducing a long-range ordered carbon/graphene/MgO ternary foam (CGMF) via surface modification and ice template method. The heat conduction shortcut provided by the vertically aligned structure of CGMF endows the composites with excellent thermal conductivity of 4.87 Wm−1K−1 (through-plane) at 12.96 vol% filler loading. Meanwhile, the barrier of MgO and PVA to the electron transmission in CGMF results in the composite with high surface electrical resistivity and volume electrical resistivity, which satisfies the requirement of electrical insulation. This work provides valuable insights into the fabrication of highly thermal conductive & electrically insulating composites.