Preparation of TEOS coated responsive nanocapsules endows the coating excellent anti-corrosion properties

Metal-organic framework (MOF) materials possess a significant specific surface area and exceptional porosity, which offer significant advantages in corrosion protection. We have created a Zeolitic Imidazolate Framework-8 (ZIF-8) nanocapsule that is responsive to changes in pH. This nanocapsule is designed for providing self-healing performance to epoxy coating and corrosion protection property on Q235 carbon steel. The classical ZIF-8 was synthesized as the nanocontainer, and the relatively high loading percentage of benzotriazole (BTA) into it was endowed the coating system with outstanding resistance to corrosion and the ability to self-healing. Furthermore, A coating of tetraethyl orthosilicate (TEOS) was deposited onto the surface of BTA@ZIF-8, which would rupture under alkaline and acidic conditions, achieving controllable release of BTA and timely repair of the damaged areas of coating, prolonging the lifespan of the coating system. The successful preparation of the BTA@ZIF-8/TEOS nanocapsules was confirmed through characterization using SEM, FTIR, and XRD techniques. BTA had a loading capacity of approximately 8.5 wt%. After a 30-day soaking period, the EIS analysis revealed that the impedance modulus of the 2 wt% BTA@ZIF-8/TEOS/EP scratch coating was determined to be 7.48 × 10 3  Ω ·cm 2 , which is much greater than the epoxy coating. The non-scratch coating, comprising 2 wt% BTA@ZIF-8/TEOS nanocapsules, demonstrated an impedance modulus above 10 7  Ω ·cm 2 following 50 days of soak. The coating provides exceptional resistance to corrosion and possesses the ability to heal itself.