Comparative protective abilities of organothiols SAM coatings applied to copper dissolution in aqueous environments

Self-assembled monolayers (SAMs) obtained by adsorption of n-organothiols molecules have been formed onto polycrystalline copper surfaces in order to build up barrier films protecting copper from oxidation. In this context, formation of n-dodecanethiol (DT), (3-mercaptopropyl)trimethoxysilane (MPTS) and 11-perfluorobutylundecanethiol (F₄H₁₁) monolayers has been elaborated on copper and evaluated by X-ray photoelectron spectroscopy while polarization and cyclic voltammetry curves were used to compare the inhibition efficiency of the three organic coatings. Furthermore, atomic absorption spectrometry measurements were carried out in domestic water and in NaCl 0.5 M solutions in order to evaluate and quantify the dissolution of copper electrodes before and after protection. Results showed evidences that, among the three organic compounds assessed, F₄H₁₁ is the most suitable candidate to slow down the copper oxidation process.