Electrical conductivity and mechanical property improvement by low-temperature carbon nanotube growth on carbon fiber fabric with nanofiller incorporation

Carbon fiber reinforced polymer composites offer many advantages due to their great combination of high strength and modulus combined with low density and light-weight; however, they typically feature low electrical conductivity. These advanced composites are often unsatisfactory compared to conventional conductive metals that are vulnerable to lightning strike damage. To develop a new generation of highly conductive carbon fiber composites that address these shortcomings, carbon nanotubes (CNTs) were grown on nickel-coated carbon fiber using low-temperature growth to create a fuzzy fiber surface. An additional conductive filler, graphene nano-platelets (GNPs), was then dispersed on the fuzzy fiber surface to form synergistic physical interactions between two different low-dimensional carbon-based nanostructures. The results reveal a synergistic enhancement in both functional conductivity and mechanical properties. The electrical conductivity of composites with the inclusion of GNPs resulted in approximately 40%, 300%, and 190% enhancement in the fiber, surface, and through-thickness direction compared to the fuzzy fiber composites. Mechanical properties, including flexural, work of fracture, impact, and interlaminar shear stress properties were further enhanced. These results reveal that the presence of GNPs creates more electron transfer pathways, and also promotes a synergistic effect in physical interactions. Altogether, these enhancements provide avenues for future high-performance conductive carbon fiber composites in aircraft structures.