Electrochemical construction of amino-functionalized GO/carbon fiber multiscale structure to improve the interfacial properties of epoxy composites

In this paper, two kinds of amino compounds with different functionalities were used to modify the surface of graphene oxide (GO), uniform and stable aqueous dispersion was prepared by adjusting the pH value. For the first time, two kinds of modified GO multi-scale reinforced structures with different morphology were successfully constructed on the carbon fiber (CF) surface by electrophoretic deposition. The analysis showed that the morphology of ethylenediamine modified GO on the surface of CF presented a “Post-it” structure, while the morphology of melamine modified GO was a “Bark” structure. The presence of the modified GO can significantly improve the specific surface area and infiltration of the fibers. Compared with untreated carbon fiber composites, the comprehensive mechanical properties of the modified composites increased by 30.8% and 40.9% respectively. The improvement of dynamic mechanical properties also means the formation of good interface layer. This research provides a novel idea for producing multi-scale reinforced materials on the fiber surface. • Multi-scale reinforced structural design of graphene oxide/carbon fiber. • The two kinds of graphene oxides show different three-dimensional structures on the fiber surface. • Graphene oxide on fiber surface increased the roughness and wettability of fibers. • The interlaminar shear strength of CF/EP composites increased significantly (40.9%). • The increase of glass transition temperature and storage modulus also means the formation of good interface layer.