Corrosion inspired inhibitor releasing for BTA@ZIF-8 modified epoxy coatings in seawater environment

The BTA@ZIF-8 mico-particles were prepared by loading benzotriazole (BTA) onto ZIF-8 according to a one-pot method, which had been used to modify the epoxy anti-corrosion coatings. It was found that the BTA could be successfully loaded onto ZIF-8 and the weight percentage of the loaded BTA was about 29 wt%. The results showed that the wet bond strength of BTA@ZIF-8 modified coatings increased by 52 % compared to the pure epoxy coatings. According to the EIS analysis, the impedance values for all the coatings were greater than 104 Ω cm2 after immersion for 0.5 h. When the immersed time lasted for 228 h, the impedance values for the pure epoxy coatings decreased to 103 Ω cm2, while the impedance values for the ZB-0.7 coatings were still above 104 Ω cm2, which indicated that the anti-corrosion performance of the EP coatings could be effectively improved by the addition of BTA@ZIF-8. The outstanding anti-corrosion ability of BTA@ZIF-8 modified epoxy coatings can be attributed to that the BTA loaded on ZIF-8 could be inspired releasing by initial corrosion to form an inhibitor film on the metal surface.