Layer-by-layer assembling MXene /poly(3-glycidyloxypropyldimethoxymethylsilane) hierarchical structure onto carbon fibers for high-performance carbon fiber/epoxy composites

Two-dimensional (2D) materials have been widely used for the construction of functional materials with enhanced properties and functions. In this work, we demonstrate the fabrication of carbon fiber (CF)-based composites through the modification of CFs with 2D MXene (Ti3C2Tx) nanosheets via the layer-by-layer (LbL) technique, which is assisted by the bridge crosslinking of poly(3-glycidyloxypropyldimethoxymethylsilane) (pGPDMS). It is found that the Ti3C2Tx/pGPDMS hierarchical structure provides powerful mechanical interlocking and chemical bonding interactions between CFs and the epoxy (EP) matrix, contributing to the formation of high-quality interface materials of CF/EP composites. Compared with unmodified CF/EP composites, the fabricated Ti3C2Tx/pGPDMS-CF/EP composites with four-layer Ti3C2Tx nanosheets exhibit the largest interfacial shear strength with an increase of 82.2%. In addition, the surface energy and compatibility of CFs are greatly improved. This study presents a potential strategy to construct hierarchical structure via 2D material modification and LbL assembly, and shows successful pathway to enhance the interfacial and mechanical performance of CF/EP composites.