Processing and characterization of multi-scale hybrid composites reinforced with nanoscale carbon reinforcements and carbon fibers

Composites with multi-scale reinforcements consisting of multi-walled carbon nanotubes (MWCNTs) or carbon nanofibers (CNFs), along with micron-sized advanced carbon fibers, were processed using electrophoretic deposition (EPD) technique. Both anodic and cathodic electrophoretic deposition processes have been utilized for the deposition of nanoscale reinforcements on carbon fibers. Through hybridization of the reinforcement scales, we have demonstrated significantly improved electrical conductivity and interlaminar mechanical properties. In particular, the multi-scale composites manufactured with the cathodic EPD process where MWCNTs and copper nano-particles are co-deposited show an increase of the through-thickness electrical conductivity by 15 times along with an improvement in interlaminar shear strength by 13% when compared to the plain woven composites. The unique microstructure based on the concurrent deposition of nanoscale carbon and nano-sized Cu particles on carbon fibers shows great potential in being able to tailor the structural and functional performance of advanced fiber composites.