Construction of hierarchical “organic-inorganic” structure by self-assembly to enhance the interfacial properties of epoxy composites

Abstract The “organic-inorganic” hierarchical structure was constructed by self-assembled MXene and chitosan (CS) on carbon fiber (CF) to promote the interfacial performance of CF/epoxy composites. The interfacial adhesion was greatly boosted because of enhanced wettability and surface energy generated by active groups of MXene and CS. The increased roughness caused by the two-dimensional layer structure of MXene gave rise to better mechanical interlocking between fiber and matrix and produced crack deflection. The hydrogen bonds and covalent bonds that may be formed between MXene and CS or fiber and epoxy also played a significant role in interfacial adhesion. Compared with pristine composites, CF-MXene-CS/epoxy composites showed impressive improvements of 49.1%, 52.1% and 54.7% in ILSS, IFSS and flexural strength, respectively. This work would provide a promising strategy to establish robust interface in CF composites with splendid interfacial properties.