Acid-Responsive Self-Healing Waterborne Epoxy Coating: Preparation, Release Behavior, and Anticorrosion Performance Based on Bowl-Shaped Mesoporous Polydopamine Nanocontainer Loaded with 2-MBI Inhibitors

We present a straightforward emulsion-induced interfacial anisotropic assembly method for in- situ synthesis of bowl-shaped, self-encapsulated mesoporous polydopamine (BMPDA) nanocontainers (M-M@P) loaded with 2-mercaptobenzimidazole (2-MBI). Results showed that the loading capacity of the bowl-shaped mesoporous polydopamine reaches 24 wt.%. The M-M@P exhibits a cumulative MBI release of 91.61% after immersion in a 3.5 wt.% NaCl solution at pH = 2 for 24 h, accompanied by a corrosion inhibition efficiency of 95.54%. Additionally, the acid-responsive M-M@P not only enables controlled release of MBI but also synergistically promotes the formation of a protective film on the carbon steel substrate via the chelation of PDA-Fe3+, thereby enhancing the self-healing performance of waterborne epoxy coatings.