A graphene film interlayer for enhanced electrical conductivity in a carbon-fibre/PEEK composite

Carbon-fibre reinforced composites are seeing increased deployment, especially in the aerospace industry, and the next-generation of these materials will need to meet demanding performance requirements beyond just specific strength. The incorporation of nanomaterials such as graphene into composites has great potential for enhancing electrical, thermal, and mechanical properties, which could then enable new capabilities such as built-in lightning strike protection and electromagnetic shielding. One major challenge is successful integration of nanomaterials into the composite during the manufacturing process especially for thermoplastic based composites. This work explores the spray deposition of exfoliated graphene in liquid suspensions for the nano-enhancement of electrical properties in carbon-fibre reinforced polyether ether keytone (PEEK) composites. Developed thin films were smooth with RMS roughness of 1.06 μm on Si substrates and RMS roughness of 1.27 μm on CF-PEEK tapes. The addition of 1.3 wt% graphene into the interlayers of CF-PEEK composites resulted in bulk electrical conductivity enhancement both in plane and through thickness of ~ 1100% and 67.5% respectively. This approach allows for pre-consolidation introduction of high-performance nanomaterials directly to thermoplastic prepregs which could open simple pathways for the in-situ manufacturing of carbon-fibre reinforced polymer nanocomposites.