Smart Self‐Healing Zinc Composite Coatings for Advanced Corrosion Protection

The conventional zinc coating can be transformed into a smart coating by incorporating pH‐responsive particles through the electro‐co‐deposition technique. Two different containers were considered: SBA‐15 and ZnO, for loading the inhibitor 2‐benzothiazolylthio‐succinic acid (BTSA). A sustained release was achieved by encapsulating it with a polymer, poly(diallyldimethylammonium chloride) (PDDA). Among both the particles, SBA‐15‐BTSA‐PDDA had a higher surface area (10 times), greater pore volume (three times), and better release percentage (two times) than ZnO‐BTSA‐PDDA. Moreover, the surface charge of the SBA‐15‐BTSA‐PDDA exhibits better stability in the dispersive medium; it was considered for electro‐co‐deposition. The surface and cross‐sectional morphology confirmed the incorporation of particles into the zinc matrix. The electrochemical analysis showed that the Zn‐SBA‐15‐BTSA‐PDDA exhibits improved corrosion inhibition performance compared to the pure Zn coating. In the EIS analysis, the Zn‐SBA‐15‐BTSA‐PDDA was immersed for 168 h with a scribe (scratch). It shows superior corrosion inhibition with a self‐healing efficiency of 87%. The accelerated exposure study of the coating using a salt spray chamber confirmed that Zn‐SBA‐15‐BTSA‐PDDA exhibited a synergistic performance in terms of corrosion inhibition and self‐healing action for advanced corrosion protection.