Facile and Scalable Strategy for Fabricating Highly Thermally Conductive Epoxy Composites Utilizing 3D Graphitic Carbon Nitride Nanosheet Skeleton

The application of high-performance thermal interface materials (TIMs) for thermal management is commonly used to tackle the problem of heat accumulation, which influences the performance and reliability of microelectronic devices. Herein, a novel three-dimensional (3D) carbon nitride nanosheet (CNNS)/epoxy composite with high thermal conductivity was developed by introducing 3D CNNS skeleton fillers prepared by a facile and scalable strategy assisted by a salt template. Benefiting from the continuous heat transfer pathways formed in the CNNS skeleton, 17.0 wt % 3D CNNS/epoxy composites achieve a superior thermal conductivity of 1.27 W/m·K, which is 6.35 and 1.57 times higher than those of epoxy resin and convention CNNS/epoxy, respectively. With the aid of theoretical model analysis and finite element simulation, the pronounced enhancement effect of the 3D CNNS skeleton on the thermal conductivity of epoxy composites is found to be attributed to the continuous 3D CNNS thermally conductive network, the diminished CNNS-CNNS interfacial thermal resistance, and the effective interfacial interactions between epoxy and CNNS. In addition, the 3D CNNS/epoxy composites possess high electrical insulation and desirable mechanical strength. Therefore, 3D CNNS/epoxy composites are promising TIMs for advanced electronic thermal management.