pH-responsive self-healing anticorrosion coatings based on benzotriazole-containing zeolitic imidazole framework

Utilization of self-healing nanocontainers with corrosion inhibitors is an efficient strategy for protecting metals from corrosion. However, self-healing coatings require the rapid release of these corrosion inhibitors to achieve an on-demand barrier on metal surface while avoiding unwanted leakage before the protective coatings are damaged. Herein, well-defined ZIF-7@BTA nanoparticles with approximately 30 wt% benzotriazole inhibitors are prepared via a ligand exchange approach. The as-synthesized ZIF-7@BTA nanoparticles can rapidly release the BTA inhibitor onto scratched areas on metal surfaces, providing 99.4% inhibition efficiency under acidic conditions. Moreover, only limited inhibitor of BTA molecules was leached out (less than 4%) in a neutral environment. Furthermore, the ZIF-7@BTA nanoparticles were further distributed in the polymer matrix to prepare the self-healing anticorrosion coatings for corrosion resistance enhancement in an acidic environment. Electrochemical impedance spectroscopy (EIS) analysis was utilized to characterize the corrosion resistance.