Construction of a mixed epoxy composite anti-corrosion coating of cerium ion-modified montmorillonite as “brick” and ZIF as “mortar”

To overcome the limitations of epoxy (EP) coatings such as inherent mechanical brittleness and insufficient barrier performance, this study developed a novel ZIF-8/Ce-MMT (ZCM) composite filler via a facile one-step synthesis approach. The resulting ZCM filler exhibits excellent thermal stability and dispersibility, and endows EP coatings with multifunctional anti-corrosion properties including enhanced barrier resistance, anodic passivation, and cathodic inhibition. Electrochemical tests demonstrate that the ZCM/EP composite coating achieves an exceptional corrosion inhibition efficiency of 93.97 %. After 50 days of immersion in 3.5 % NaCl solution, the coating containing only 1.5 wt% ZCM maintains a low-frequency impedance modulus 39.5 times higher than that of pure EP. Furthermore, the composite coating exhibits outstanding wear resistance with a 19.3 % reduction in mass loss compared to unmodified EP. The ZCM/EP system represents a significant advancement in multifunctional protective coatings, combining passive barrier enhancement with active self-healing behavior and improved mechanical durability, offering a new strategy for designing high-performance anti-corrosion coatings under demanding service conditions.