Dynamic Metal-Organic Framework/Polymer Hybrid Microcapsules for Self-Healing Anticorrosion Coatings

摘要

An ideal microcapsule effectively preserves active molecules and can rapidly release it to elicit a self-healing anticorrosion function. However, the development of highly efficient microcapsules remains a great challenge. Herein, polymer/metal-organic framework hybrid microcapsules with dynamic properties were constructed as self-healing anticorrosion coatings. The shell of the microcapsule consisted of flexible polydopamine and a hard crystalline zeolitic imidazolate framework-8 layer. The corrosion inhibitor 8-hydroxyquinoline was trapped in the microcapsules and remained unreleased because the ZIF-8 layer acted as a molecular sieve. When the coating was surrounded by an acidic environment, the ZIF-8 nanocrystals in the shell dissociated, followed by the release of corrosion inhibitor. A dense protective layer was formed on the steel surface to suppress extensive corrosion propagation. In contrast to conventional coatings, the novel dynamic hybrid microcapsules enable the application of self-healing coatings that can withstand harsh acidic environments without human intervention.