Title: A derivative of chalcone as green corrosion inhibitor for copper

Abstract

Antioxidant compounds have been important in various fields. For example, they are used in medicine and biology as they protect the human body from damage caused by reactive oxygen species or free radicals. Antioxidant agents are organic compounds that contain electronegative heteroatoms and that are compatible with health and the environment, as special characteristic required by corrosion inhibitors. There are two groups known as organic antioxidant compounds: flavonoids and their precursors, the chalcones. Several studies have shown that chalcones and their derivatives have anti-inflammatory, analgesic, antitumor, repellant, and UV-protective properties. Antioxidant properties are attributed to the presence of heteroatoms such as Oxygen, Nitrogen, Sulfur, etc. Therefore, in this work, a synthesized derivative of chalcone called A2 which contain Oxygen and Fluor as electronegative heteroatoms, was studied as a corrosion inhibitor for copper in acid medium using electrochemical techniques, such as Electrochemical Impedance Spectroscopy (EIS), Pontentiodynamic Polarization Curves (PPC), Electrochemical Noise (EN), quantum chemical calculations (QCC) and adsorption isotherms (AI). The best efficiency obtained by EIS experiments was in the presence of 300 ppm of A2. PPC showed the influence of A2 over the anodic curve and its slope that was shifted to more negative potential (40mV). It was attributed to the adsorption process of the inhibitor on the double layer. Also, the efficiency from PPC was 83% at the same concentration (300 ppm). Furthermore, the EN technique over a period of 24 hours corroborated the development of a A2 layer over the metal surface. It was also confirmed by the isotherm values, where the best fit for the Langmuir model was observed with and G = -23 KJ/mol, and the results of chemical quantum calculations on the high value of softness can be related to the adsorption process of A2 on the metal surface.