The role of embedded 2-ABT@Cu-BTC MOF on the anti-corrosion performance of electro-assisted deposited silica sol-gel composite film

Using electro-assisted sol-gel method, composite coatings of silica sol-gel reinforced with metal-organic frameworks are formed on a nickel binary alloy. The metal-organic framework of Cu-1,3,5-tricarboxylate (Cu-BTC MOF) embedded in the sol-gel matrix acts as the reinforcing phase. Cu-BTC MOF loaded with 2-aminobenzothiazol (2-ABT) was prepared by the encapsulation method. The resulting micro-particles were characterized and the encapsulation of the 2-ABT inhibitor was confirmed. Loading capacity was about 10.7 mg of 2-ABT per 100.0 mg of modified Cu-BTC MOF. The release of the inhibitor has been investigated by cyclic voltammetry and it has been determined that 40% of 2-ABT is released after 24 h. The mechanism of release is based on the low electrostatic attraction between inhibitor molecules in the outer layer of Cu-BTC MOF. The effect of Cu-BTC MOF and 2-ABT@Cu-BTC MOF on the corrosion parameters of silica sol-gel coating was investigated by electrochemical experiments in a 3.5 wt% NaCl solution. It was shown that encapsulation of corrosion inhibitor can effectively protect the silica sol-gel composite coating against corrosion. Loading MOFs with 2-ABT inhibitor retards the corrosion process of the coating during storage in the corrosive solution. [Display omitted] •Cu-BTC MOF is used to fabricate silica sol-gel composite coatings on nickel binary alloy.•Silica composite films are prepared through the electro-assisted sol-gel method.•The effect of 2-ABT inhibitor loaded in Cu-BTC MOF on coating corrosion parameters is investigated.•Loading MOFs with 2-ABT inhibitor improves the corrosion parameters of the coating.•MOF was used as microcapsule to disperse the corrosion inhibitor and improve its shielding effect.