Regarding the fibre sizing method, GRMs were dispersed in the fibre sizing and then coated onto the CFs, which also contributed to significant enhancements in flexural properties and ILSS . In addition, Zhang et al. reported synergy effect by using CNT, GO and Ag nanoparticle, combining electrodeposition and chemical grafting, and the CF-Ag-GO-CNTs one resulted with the 69.7% higher interfacial shear strength (IFSS) compared with the untreated CFRP composites. Zhao et al. proposed layer-by-layer method to graft CNTs onto CFs, and achieved improved IFSS without reducing CF tensile strength. Apart from decorating CFs, GRMs have also been utilised in modifying the epoxy resin. Adak et al. functionalized GO with polyethyleneimine and then dispersed in the epoxy via solution method, as a result of the functional groups, ~60% and ~67% improvements on tensile and flexural strength of the composites were achieved. Kim et al. functionalized graphene nanoplatelets (GNPs) noncovalently via π-π interactions with poly(4-aminostyrene) (PAS), and as a result of better dispersion and crack bridging, 252% and 142% improvements in ILSS and fracture toughness were obtained with 4 wt.% PAS-GNPs. Du et al. made partially cured 1 wt.% graphene/epoxy interleaves and then co-cured with CFRP composites, which achieved a remarkable 140% increase in mode I interlaminar fracture energy. Qu et al. introduced different loadings of GO to modify the epoxy, and the ILSS reached the peak value at the 0.2 wt.% loading, where ~18% improvement was achieved. Hung et al. introduced GO into CFRP composites by two methods, disperse into epoxy resin and coat onto the surface of carbon woven fabric via EPD, and the latter one achieved with a more significant improvement in the mechanical properties of composites. Generally, functional groups play a key role on the improvement of interfacial properties, and CFs decorated with GRMs is a promising method to strengthen the CFRP composites.