Ultrahigh in-plane thermal conductive epoxy composites by cellulose-supported GnPs@PDA skeleton under stress-induced orientation strategy

Abstract

Designing anisotropic thermally conductive networks in thermal management materials can effectively exploit the high in-plane thermal conductivity of two-dimensional fillers to achieve high heat transfer efficiency along the predetermined direction, which is the hotspot for thermal management materials. However, constructing such an interconnected network with an orderly alignment structure through thermally conductive fillers has proved challenging. In this study, a high-density cellulose-supported GnPs@PDA skeleton with an interconnected and ordered structure was successfully prepared through the stress-induced strategy. After embedding into the epoxy resin, the EP/CGP composites with 22.1 vol% filler content exhibit an excellent in-plane thermal conductivity of 8.39 W/mK under a 75 % compression ratio, which is 12.3 times higher than that without compression. The enhancement of thermal conductivity for EP/CGP composites under the stress-induced orientation strategy is illustrated by the finite element analysis and metal foam theory. Furthermore, the transient heat transmission processes of the composites are recorded to verify their prospect in thermal management applications. This novel approach sheds light on the fabrication of thermally conductive networks with interconnected and ordered structures for next-generation thermal management materials.