The influence of graphene oxide filler on the electrical and thermal properties of unidirectional carbon fibre/epoxy laminates: effect of out-of-plane alignment of the graphene oxide nanoparticles

The influence of out-of-plane alignment of Graphene Oxide (GO) platelets used as matrix filler on the through-thickness electrical and thermal conductivity of unidirectional (UD) carbon fibre reinforced polymers (CFRP) composites has been investigated. By utilising an external AC field, the orientation of GO flakes was altered to take advantage of the higher electrical and thermal conductivity along the graphene basal planes. Commercially available GO was dispersed in quantities up to 5 wt% into the epoxy matrix prior to vacuum infusion into dry carbon fabric to form CFRP laminates. Both GO modified CFRP laminates containing randomly oriented GO and aligned GO modified CFRP (A-GO/CFRP) laminates were manufactured to assess the influence of the application of the electric field. Measurements of the electrical conductivity revealed markedly increased values for the A-GO/CFRP even with low filler contents. The thermal conductivity, albeit increased in A-GO/CFRP, only resulted in modest improvements. Mechanical tests of the interlaminar shear strength (ILSS) showed that the A-GO/CFRP laminates exhibited significantly improved behaviour and retained higher ILSS values (than the randomly aligned GO CFRP laminates) even at high filler contents.