Tailoring of Si–C–N–O ceramic-coated reduced graphene oxide by oil/water-solution process for high thermal conductive epoxy composite with electrical insulation

Abstract 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.