Interfacial reinforcement of composites by the electrostatic self-assembly of graphene oxide and NH3 plasma-treated carbon fiber

Abstract

The introduction of graphene oxide (GO) on the surface of carbon fiber (CF) is considered an effective strategy to modulate the structure and properties of the fiber/matrix interface in CF reinforced polymer composites. However, the tensile strength of fibers often decreases due to the etching effect during treatment. In this study, a new method was proposed to graft GO onto fiber surfaces by electrostatic self-assembly. The results showed that NH2 grafted onto CF through NH3 plasma treatment caused CF and GO to have opposite charges in deionized water; subsequently, they self-assembled to form CF@GO due to the electrostatic force. The tensile strength of CF@GO was 31.23% greater than that of pristine CF, which may be because the different sizes of GO repaired the surface defects on the CF with its multilayer restoration structure. The CF showed a noticeable improvement in surface wettability due to the GO coating. Moreover, the interfacial properties were significantly improved, with the interfacial shear strength (IFSS) of CF@GO increasing to 81.31 MPa, which was about twice that of unmodified CF. This work provides a promising strategy for nondestructive grafting nanoparticles on CF to build a strong interface in CF composites.