Effect of electrophoretic deposition followed by solution pre-impregnated surface modified carbon fiber-carbon nanotubes on the mechanical properties of carbon fiber reinforced polycarbonate composites

In this work, an impregnated carbon fiber-carbon nanotubes (CF-CNTs) hybrid fiber mat with excellent ability to enhance mechanical property was fabricated via combining electrophoretic deposition (EPD) process and the following solution pre-impregnation treatment. Their effects on the mechanical and electrical properties of carbon fiber reinforced polycarbonate (PC) matrix composites (CFRP) were systematically investigated. The results showed that the functionalized CNTs were uniformly coated on CF surface after the EPD treatment and the nano-coating enhanced the contact area and surface wettability of CF. Coupled with the solution pre-impregnation treatment, the CF-CNTs fiber bundles were fully impregnated by PC matrix and the interface connection was also improved. Compared with CF/PC composites, mechanical property was improved significantly. The tensile strength (344.8 MPa) and modulus (37.8 GPa) were improved by 46.5% and 57.5%, respectively, surpassing most of the reported values. The impact strength (36.5 kJ/m²) and storage modulus (49.0 GPa) obtained the 268.7% and 78.4% increment, respectively. In addition, the through-thickness electrical conductivity achieved 53.8% improvement. This investigation confirms that the impregnated CF/CNTs hybrid fibers own outstanding mechanical property enhancement function, which are suitable for preparing CF/CNTs reinforcements with high mechanical properties.