Study on graphene modified organic anti-corrosion coatings: A comprehensive review

This paper summarized and collated international literatures on graphene organic anticorrosion coatings in recent ten years and hierarchical and organized knowledge structures were formed. According to the role of graphene, from the perspective of theoretical and applied research, the improvement of graphene on organic anti-corrosion coatings were reviewed. In terms of the improvement of graphene on the shielding effect of coatings, the paper discussed the dispersion methods and orientation technology of graphene. A variety of graphene dispersion methods reported in the literatures were systematically organized according to dispersant groups, modification mechanisms, dispersion mechanisms and preparation processes. In terms of functional synergy, the functionalization of graphene was divided into two aspects. They were enhancement of adhesion and self-healing of the coatings. The increase in adhesion was attributed to the covalent bonds between the functional groups on the surface of graphene and the metal matrix. In the studies on self-healing of the coatings based on modified graphene, graphene acted as the load platform for self-healing functional groups. According to the self-healing groups supported by graphene, the self-healing mechanism was divided into catalytic passivation film and corrosion inhibitor adsorption film. Then, the paper discussed the practical problems and doubts encountered in the research and application of graphene in the field of anticorrosion, and that was the local corrosion acceleration phenomenon caused by the conductivity of graphene. Meanwhile, the way to solve the promotion of local corrosion were proposed. Finally, from the macroscopic, mesoscopic and microscopic perspectives, the paper summarized and discussed the influence mechanism of graphene conductivity and its orientation on the shielding effect and cathodic protective performance of zinc-rich coatings.