The reinforcing role of 2D graphene analogue MoS2 nanosheets in multiscale carbon fibre composites: Improvement of interfacial adhesion

Abstract In this study, a novel scalable method based on hydrothermal-assisted ball milling was used to simultaneously synthesize and amino-functionalize molybdenum disulfide nanosheets with diaminodiphenyl sulfone (DDS-MoS2). This process resulted in the production of the functionalized nanosheets with a lateral dimension of ~600–900 nm and thickness of ~2–6 nm without requiring a lithium intercalation step. The inverse gas chromatography results revealed that total surface energies of the nanosheets significantly increased after DDS functionalization, making them highly compatible with epoxy resin. Epoxy nanocomposites containing 0.5 wt% of DDS-MoS2 nanosheets showed ~30% and ~28% increases in tensile and flexural strengths, respectively. Additionally, ~16% and ~12% enhancements in tensile and flexural modulus, respectively, were observed in these nanocomposites. The inclusion of DDS-MoS2/epoxy resin in carbon fibre composites led to the fabrication of multiscale nanocomposites with improved mechanical properties. In these multiscale nanocomposites, flexural modulus and strength were considerably improved by ~33.7% and ~29.5%, respectively. Compared to other two-dimensional nanomaterials, such as nanoclay and graphene derivatives, DDS-MoS2 nanosheets showed promising behaviour for both epoxy nanocomposites and multiscale carbon fibre nanocomposites. These achievements could be associated with the synergistic effect of DDS-MoS2 in both promoting the interfacial stress transfer and the energy dissipation through different crack retardation mechanisms.