Fabrication of a Curcumin@Cu-BTC MOF Smart Anti-Corrosion Coating for Copper

The curcumin@Cu(II)-benzene-1,3,5-tricarboxylate metal-organic framework (Cur@Cu-BTC MOF) coating, as a pH-sensitive smart anti-corrosion coating, has been synthesized by encapsulating Cur, as a green inhibitor, in Cu-BTC MOF. The characteristics of the coating were investigated by scanning electron microscope (SEM) images, energy dispersive X-ray spectroscopy (EDS), elemental scattering map, FTIR spectroscopy and X-ray diffraction (XRD) patterns. Corrosion parameters of Cur@Cu-BTC MOF smart coating in 3.5 % NaCl corrosive solution were investigated using potentiodynamic polarization (Tafel) plots and electrochemical impedance spectroscopy (EIS). Indeed, curcumin loading into Cu-BTC MOF makes the coating more compact. The inhibition efficiency of Cur@Cu-BTC MOF coating is 72.57 %. Also, when curcumin is loaded into Cu-BTC MOF, its consumption is about 6 times lower than using it directly as an inhibitor. Also, the anti-corrosion performance of the smart coating was measured in different immersion times in 3.5 % NaCl solution. Using UV-vis spectrometry, it was found that the synthesized Cur@Cu-BTC MOF nanocapsules have a loading capacity of 16.6 % for curcumin. Cur@Cu-BTC MOF acts as a smart coating and responds to the decreasing of the local pH caused by the corrosion reaction. Encapsulated curcumin is released in response to the pH stimuli and acts as a corrosion inhibitor. The curcumin@Cu-BTC MOF coating, as a pH-sensitive smart anti-corrosion coating for Cu, has been synthesized by encapsulating curcumin (Cur) in Cu-BTC MOF. Corrosion parameters of Cur@Cu-BTC MOF smart coating in 3.5 % NaCl corrosive solution were investigated using Tafel plots and electrochemical impedance spectroscopy. When Cur is loaded into Cu-BTC MOF, its consumption is about 6 times lower than using it directly as an inhibitor.image