Influence of graphene oxide content on the morphology and properties of carbon fiber/epoxy composites

Abstract In this article, the influence of graphene oxide (GO) content on the morphology and properties of carbon fiber/epoxy (CF/EP) composites was investigated. To obtain CF/EP composites with uniform dispersion of GO, electromagnetic stirring and ultrasonic dispersion techniques were employed in the wet transfer process. Combined with a new molding process, CF/EP composites with different GO content were prepared. The test results showed that the bending strength of CF/EP composites could be effectively improved by adding GO, among which 0.5 wt% GO–CF/EP composite exhibited the best bending strength and modulus increased by 47.20% and 21.24%, up to 1158.9 MPa and 115.3 GPa. Likewise, the mode I interlaminar fracture toughness (G_IC) of the composite at the beginning of crack and the maximum during the propagation increased by 28.13% and 21.57%, reached 327.5 and 656.6 J/m², respectively. The distribution of GO in the composites and the fracture morphology of the composites were observed. Finally, according to the test results and microscopic morphology analysis, the enhancement and failure mechanism of GO in CF/EP composites were clarified. It was found that GO could improve the properties of CF/EP composites by enhancing the interface properties of CF/matrix, enhancing the strength of the matrix and forming a net‐like structure inside the matrix.