Improvement of Anti-Corrosion Performance of a Cu-Ni Bimetallic Organic Framework Smart Coating Using Amino-Substitution Triazole

In this study, a smart pH-sensitive anti-corrosion coating was fabricated by encapsulating 3-amino-1H-1,2,4-triazole (3-AT) as a corrosion inhibitor in a copper-nickel bimetallic organic framework (BMOF). The corrosion process of the coating was investigated in a corrosive solution of 3.5 wt% NaCl using potentiodynamic polarization (Tafel) plots and electrochemical impedance spectroscopy (EIS). The synthesized 3-AT@Cu-Ni-BTC BMOF has a loading capacity of 20.8 % for 3-AT. 3-AT encapsulated in BMOF is released as the corrosion zone becomes acidic and it serves as a corrosion inhibitor. The sensitivity of this coating to pH has been confirmed by the UV-Vis method. The released 3-AT inhibitor has an efficiency of 62.5 % to protect stainless steel against corrosion in the corrosive solution with reducing of optimal dosage by a factor of 4. The equivalent concentration of the released inhibitor is less than 1.25x10(-3) M after 1 hour. As found in this study, the consumption of the corrosion inhibitor can be significantly decreased in a 3.5 wt% NaCl solution with the pH-sensitive feature of the 3-AT@Cu-Ni-BTC BMOF smart coating.