▎ 摘　　要

Polymer composites with high thermal conductivity are required for addressing the heat management issues associated with the rapid growth of electronic device technology. As a strategy to improve the heat dissipation ability of composites, graphene has been attracting attention as a filler due to its superior high thermal conductivity. However, its high electrical conductivity poses a challenge for use in electronic applications. In this study, we report the synthesis of silicon oxycarbonitride-coated reduced graphene oxide (SiCNO-rGO) by an oil/ water biphasic solution process to improve the thermal conductivity of epoxy composites. The precursors are prepared by controlling the hydrolysis/condensation reactions and are subsequently transformed to polymer derived ceramics by pyrolysis. The manufactured Al2O3/epoxy composite, with assembled SiCNO-rGO, exhibits excellent interfacial adhesion due to the structural affinity between the filler and matrix, homogeneous dispersion, and a synergistic effect with the hybrid fillers. The thermal conductivity of the SiCNO-rGO/Al2O3/epoxy composite can reach up to 2.29 W m(-1) K-1, corresponding to a thermal conductivity enhancement of about 1662%. Moreover, the insulating property of the epoxy composite is still retained up to a SiCNO-rGO loading of 3 wt %. This approach to the surface modification of graphene provides a potential tool for heat management in a wide range of thermal conductive applications.