Functionalization with MXene (Ti3C2) Enhances the Wettability and Shear Strength of Carbon Fiber-Epoxy Composites

MXene is a two-dimensional transition metal carbide or carbonitride with graphene-like 2D morphology and high surface activity, which are useful features in energy storage, catalysis, and adsorption. However, only a handful of structural applications have so far been reported. In this study, functionalization of a carbon fiber (CF) was achieved by MXene (Ti3C2) to improve the CF surface wettability. The results showed that functionalization of MXene not only changed the CF surface topography and increased the mechanical engagement effect during debonding but also enhanced the surface activity of carbon fibers. The interfacial shear strength increased by 186% when compared with nonfunctionalized specimens. A possible interfacial enhancement mechanism was proposed to provide a future roadmap for surface modification of carbon fibers.