Controlled attachment of polycarbonate nanoparticles on carbon fibers for increased resin impregnation and interfacial adhesion in carbon fiber composites

The favorable interfacial properties of carbon fibers (CFs) and matrix are the key to the design and fabrication of a CF reinforced composite with superior micromechanical properties for various modern technological applications. However, high viscosity of a thermoplastic polymer makes resin infusion difficult, resulting in poor impregnation into CFs, ultimately leading to insufficient interfacial adhesion during composites fabrication process. Here the polycarbonate nanoparticles (PC-NPs) were pre-coated on the CFs from PC-NP aqueous solution and formed compact microstructure, which significantly improved the resin impregnation around CFs and interfacial adhesion between CFs and PC matrix. This PC-NP assisted CF/PC composite exhibits an increased interfacial shear strength up to 37.03 MPa, which is ~67.25% higher than that of un-coated CF/PC composite. Moreover, the tensile strength and flexural strength are enhanced remarkably by ~41.06% and ~22.16% increase, respectively. These results therefore demonstrate that the attachment of thermoplastic PC-NPs is a facile, environmental-friendly and viable approach in design and modification of the interfacial properties of CFs and PC matrix, which can be expanded for other multifunctional CF-reinforced composites with unique micromechanical properties for various practical applications.