Preparation and properties of epoxy composites reinforced by three-dimensional wood sponge-graphene

The selectively etch nature balsa wood, leading to a wood sponge with three-dimensional(3D) lamellar structure. After loading a certain proportion of reduced graphene oxide(rGO) and graphene nanosheets(GNP), the graphene-wood sponge(G-WS)/epoxy resin composite was prepared by vacuum impregnation and curing with epoxy resin. After loading graphene via hydrothermal reduction, graphene oxide(GO) is reduced to rGO. During the self-assembly of rGO sheets, GNP are wrapped and connected by rGO sheets by π-π interactions. Meanwhile, G-WS can also maintain the good 3D structure after vacuum impregnation. The lamellar structure inherited from the wood stock that can lead to anisotropic conductivity G-WS with epoxy resin, at loading of 1.45%(mass fraction, the same below), represents a high through-plane thermal conductivity of 1.59 W·m-1·K-1, compared to the neat epoxy matrix, which is equivalent to a significant enhancement 457% of per 1% loading. The lamellar structure made the G-WS can achieve 80% compression and 40% deformation and compression cycles for 100 times without significant deformation.