A novel π bridging method to graft graphene oxide onto carbon fiber for interfacial enhancement of epoxy composites

Based on the inherent crystallite structure of carbon fiber, a novel and facile method was presented to balance the tedious steps and effectiveness of graphene oxide/carbon fiber (GO/CF) hierarchical reinforcement, by establishing π bridging of GO and CF under the assistance of pyrene-containing compounds, which was performed without chemical treatment of CF and GO. The surface chemical elements, functional groups, wettability , morphologies and surface structures of obtained reinforcements were characterized through XPS , FT-IR, dynamic contact angle , SEM and Raman spectroscopy , respectively. This method could implement at room temperature without causing damage to CF as indicated by filament tensile strength test. The resulted composites with a bridging agent of 72 mmol/L have the highest interlaminar shear strength , transverse fiber bundle strength and interfacial shear strength which increased by 49.3%, 117.1% and 59.1%, respectively, compared to pristine CF composites.