Facile fabrication of large 3D graphene filler modified epoxy composites with improved thermal conduction and tribological performance

Abstract A simple method to fabricate three-dimensional graphene fillers (3DGFs) modified epoxy resin (EP) composite was developed in this study. This method offers a flexible fabrication process and the polymer composites obtained preserve to some extent the advantages of the traditional 3D graphene foam structure. The thermal conductivity of 3DGF/EP composites was increased successfully to 0.52 W/mK with only 0.14 vol% (0.27 wt%) graphene loading which is 1.74 times higher than that of the neat epoxy. This remarkable improvement normalized by graphene loading (i.e., the thermal conductivity enhancement efficiency) is amongst the highest reported values of carbon-based nanofiller-epoxy composites. The unique hollow 3D structure, defect-free feature and large length-thickness ratio of 3DGF compared to conventional graphene sheets are responsible for the high thermal conductivity of the epoxy composite. Further, finite element analyses also confirmed the positive effect of the filler length-thickness ratio on the thermal conductivity of 3DGF/EP composites which agreed well with experimental results. Moreover, the tribological performance of the composites was also improved by incorporation of 3DGFs.