Multiple molecular chains grafted graphene oxide chelated with cerium cation towards anti-corrosion and anti-wear application

Graphene Oxide (GO) nanosheets show great potential in the field of corrosion protection owing to their lamellar structure and remarkable mechanical features. However, these nanosheets are highly susceptible to agglomerating in waterborne epoxy resin (EP) matrix, which results in their structure degradation and restricts their application in anti-corrosion field. To address this challenge, a novel approach is employed in this study, involving the synthesis of multiple molecular chains (PEI and EDTA) grafted GO nanosheets (designated as EAGO), and subsequently chelated with cerium cations (CEAGO). The grafting of multiple molecular chains solves the agglomeration phenomenon of GO nanosheets during the coating preparation process. Such an advanced structural design is crucial for corrosion protective coatings since the unique structure of grafted EDTA enables effective chelating of corrosion inhibitors to provide anti-corrosion and self-healing features, while the steric hindrance effect of multiple molecular chains restricts the mobility of EP molecular chains, thereby enhancing anti-wear properties. The CEAGO/EP coating achieves a corrosion protection efficiency of up to 96.53%, and the wear rate of the CEAGO/EP coating is approximately 62.88% lower than that of pure EP. Electrochemical Impedance Spectroscopy (EIS) and White-light interferometer (WLI) results demonstrated that the epoxy coating loaded with CEAGO nanosheets could provide robust corrosion protection and wear resistance for 6082 aluminum alloy.