Research progress of dispersion modification and anticorrosion mechanism of graphene and its derivatives in coatings

Graphene (Gr) has excellent properties such as super-isolation, super-hydrophobicity and super-high specific surface area, making it a revolutionary material for improving the anticorrosion performance of coatings in the 21st century. However, it is easy to agglomerate due to the Van Der Waals force and the high specific surface area between Gr layers, which limits its application in the anti-corrosion coatings. The dispersion modification of Gr can promote its uniform distribution in the coating, which is of great significance to improve the anticorrosive properties of the coating. This paper introduces the structural characteristics of Gr and the anticorrosion mechanism of Gr in coatings, and summarizes the methods of Gr dispersion modification, including the covalent modification of Gr with the small organic molecules, the organic polymers and the inorganic nanoparticles, the non-covalent modification of Gr through the π-π interaction, the hydrogen bonding and the ionic bonding, doping Gr to introduce the new elements and giving it excellent performance, and through the in-situ polymerization to improve the compatibility between Gr and polymer. According to the dispersion principles such as increasing the interlayer steric hindrance of Gr, changing the amphiphilicity of its surface and increasing its compatibility with the polymer, the dispersibility of Gr can be improved remarkable. The uniformly distributed Gr forms a hydrophobic network in the coating, which can effectively improve the corrosion resistance of the coating and expand the application range of the coating. In addition, the paper also analyzed the advantages and disadvantages of various modification methods, and proposed a research direction to further improve the dispersion of Gr and its derivatives; summarized the mechanism of Gr and its derivatives in anti-corrosion coatings, and suggested to strengthen the research on the anti-corrosion mechanism based on experimental exploration in the future. © 2021, Editorial Office of Acta Materiae Compositae Sinica. All right reserved.