Magnetic-induced dynamically enhanced in-plane or out-of-plane thermal conductivity of BN/Ag NWs@Ni/epoxy composites

Abstract

The thermal conductivity of polymer composites could be improved through the orientation of fillers in specific directions. Here, a novel strategy to fabricate BN/Ag nanowires@Ni/epoxy composites (BN/Ag NWs@Ni/EP) to dynamically improve the in-plane or out-of-plane thermal conductivity of the composites in real-time by changing the direction of the magnetic field was investigated. The thermal conduction path was constructed by Ag NWs bridging between BN flakes. Ag NWs@Ni would be oriented in the in-plane or out-of-plane direction by changing the direction of the magnetic field. The out-of-plane or in-plane thermal conductivities of the composites were 0.824 and 0.723 W m−1K−1 at 40 wt% BN/Ag NWs@Ni content, and the corresponding TCEs were 429% and 359% respectively when Ag NWs@Ni was oriented in the out-of-plane or in-plane direction. Meanwhile, BN/Ag NWs@Ni/EP exhibited good mechanical and dielectric properties, which were beneficial for its industrial application in electronic packaging. This strategy provides the possibility for the applications that required the adjustment of the heat conduction direction in real-time.