Preparation and properties of graphene-epoxy/alumina foam composites

Graphene-epoxy/alumina foam composites were prepared by repeated impregnation of alumina foam with a graphene oxide (GO) suspension and drying, followed by annealing at 600 to 1 000℃ under an Ar atmosphere and infiltration of epoxy and crosslinking agents into the foam under vacuum. XRD, SEM and Raman spectroscopy were used to characterize the microstructures of the composites. Results indicated that the GO was reduced more thoroughly at a higher annealing temperature. The thermal and electrical conductivities of the composite reached 2.11 W/m·K and 45 S/m, respectively, with a GO content of 0.533 wt% when an annealing temperature of 1 000℃ was used. The graphene loaded on the surface of the alumina foam greatly increased the thermal and electrical conductivities of the composites while the alumina foam network contributed to the fast phonon transport, which favored heat transport.