Constructing a "pea-pod-like" alumina-graphene binary architecture for enhancing thermal conductivity of epoxy composite

Constructing a three-dimensional thermal transport framework is an effective strategy for enhancing thermal conductivity of polymer composites. Vacuum-assisted filtration has been utilized as an effective method to prepare heat spreader films, which always exhibit poor heat dissipation performance in the axial direction. Herein, with the incorporation of spherical alumina, a pea-pod-like binary alumina-graphene architecture has been fabricated via vacuum filtration and impregnated with epoxy to obtain alumina-graphene/epoxy composite. The thermal conductivity of epoxy composite in axial direction has risen to 13.3 Wm(-1) K-1 with the assistance of pea-pod-like binary alumina-graphene foam with 12.1 wt% graphene and 42.4 wt% alumina loading. Thermal conductivity of the composite in radial direction reached 33.4 Wm(-1) K-1, which exhibits about 166 times enhancement than that of pure epoxy. The test result of the thermal conductivity of the composite under various conditions and heat transport applications confirmed the excellent thermal transport performance of the composite. Our work provides a new idea to significantly enhance the thermal conductivity of thermal management materials.