Factors Affecting the Quality and Corrosion Inhibition Ability of Self-Assembled Monolayers of a Schiff Base

Self-assembled monolayers (SAM) of a Schiff base were prepared on a copper surface under different conditions, and the quality and protection ability of resulting films against aqueous corrosion of copper were evaluated by alternating current (AC) impedance technique. Some factors, including surface treatment and applied potentials during and after self-assembly, were investigated. The results indicate that nitric acid (HNO₃) etching of the copper prior to adsorption can improve the quality and corrosion inhibition ability of SAM significantly. An appropriately applied potential during self-assembly contributed to the improvement of the quality of SAM, and the long hydrocarbon chain in the molecular structure of the Schiff base enhanced the protection of SAM. Fourier transform infrared (FTIR) reflection spectroscopy and x-ray photoelectron spectroscopy (XPS) were used in the analysis of SAM.