ZIF-8 based bifunctional coatings with anticorrosive and antibacterial properties: A new design strategy for more efficiency

An efficient and simple in-situ/mechanical two-step strategy has been discovered for the fabrication of nanocontainers based on zeolite imidazole framework-8 (ZIF-8) with corrosion inhibitors (benzotriazole, BTA). The nanocontainers were applied in anticorrosive coatings with anticorrosion and antibacterial bifunctions for aluminum alloys AA2024. The effects of ZIF-8 modified with the corrosion inhibitor via different methods (in-situ, mechanical, and two-step strategies) on its morphology, composition, structure, loading/release behavior were studied and discussed. Results showed that the amount of loaded BTA was positively correlated with the crystal size of the final ZIF-8, impacting sustained release. Compared with the conventional primary load (in-situ and mechanical loading way), the two-step loading method (in-situ followed by mechanical treatment) achieved a higher BTA loading without evident ZIF-8 morphology and structure changes. The two-step modified (2-BTA@ZIF-8) powders exhibited good corrosion inhibition and remarkable antibacterial properties against Escherichia coli and Staphylococcus aureus. Additionally, the 1-BTA@ZIF-8 (in-situ strategy), 1-BTA/ZIF-8 (mechanical strategy) and 2-BTA@ZIF-8 composites were dispersed in acrylic resin to prepare anticorrosive and antibacterial bifunctional coatings. Results showed that the 2-BTA@ZIF-8 incorporated acrylic coatings exhibited superior anticorrosion performance and antimicrobial activity compared to the unmodified coating due to the controlled release of BTA. Thus, elaborated strategy represents a feasible and effective way to construct high-performance anticorrosive and antimicrobial coatings with metal-organic framework materials.