Synergistic effects of hybrid MWCNT/nanosilica on the tensile and tribological properties of woven carbon fabric epoxy composites

An epoxy matrix incorporated with hybrid multi-walled carbon nanotube (MWCNT) and nanosilica was used to fabricate woven carbon fabric epoxy composites using vacuum-assisted resin infusion molding (VARIM). Three types of multi-scale hybrid composites containing 0.2 wt.% MWCNT + 0.7 wt.% nanosilica, 0.7 wt.% MWCNT + 0.2 wt.% nanosilica, and 0.45 wt.% MWCNT + 0.45 wt.% nanosilica were prepared to investigate both tensile and tribological properties, simultaneously. The results of tensile and tribological experiments showed that specimens containing 0.45 wt.% MWCNT + 0.45 wt.% nanosilica were better than the corresponding single-type nanoparticles with the same total weight percentages. Especially, the tensile strength and tensile modulus of composite specimens containing 0.45 wt.% MWCNT + 0.45 wt.% nanosilica increased by 25.2% and 31% in comparison with the neat composites, while their friction coefficient and wear rate decreased by 88% and 98% in comparison with the neat composites, respectively. The SEM images of fracture surfaces showed that the incorporation of nanoparticles enhanced the fiber-matrix interfacial strength, toughened the surrounding matrix, and improved resin adhesion to the fiber, which increased tensile properties of incorporated composites with hybrid nano-fillers. Moreover, by adding the hybrid nanoparticles to the unfilled carbon fabric composites, the friction coefficient variation of these specimens totally changed, which led to an improvement in the friction-reducing ability and wear rate resistance. In conclusion, a method is suggested in this paper to incorporate hybrid nanoparticles for benefitting from the properties of both nanoparticles at higher weight percentages.