Dendritic silica@MOF core–shell nanocontainer for preparing smart coating with active–passive synergistic anticorrosion

Corrosion poses a critical threat to industrial safety and service life of metallic materials, yet conventional protective coatings lack the responsive functionality for long-term active protection. To address this limitation, a pH-responsive core-shell nanocontainer is designed to achieve intelligent corrosion protection by integrating active inhibitor release and passive barrier enhancement. The nanocontainer consists of dendritic silica (DPS) as a porous core for loading corrosion inhibitors, encapsulated by a ZIF-67 shell that responds to local pH changes. When incorporated into a waterborne epoxy coating, the system demonstrates both on-demand self-healing at defect sites and long-term barrier stability. Electrochemical tests showed that the |Z| 0.01 Hz of the composite coating remained at 3.3 × 10 7 Ω·cm 2 after immersion in 3.5 wt% NaCl solution for 28 d, and the charge transfer resistance at a scratch was about 4.6 times higher than that of the blank coating after 48 h. This work presents a novel design approach for multifunctional anticorrosion coating with combined active and passive protection mechanisms.