Inhibition mechanism of self-assembled epoxy-silane/dithiol film on copper corrosion

Inhibition effects of an epoxy-silane/dithiol film on copper corrosion in 3.5 wt% NaCl solution were studied by digital holography, electrochemical methods and surface characterization approaches. In-situ observation of the concentration change at the electrode/electrolyte interface during dynamic potential scan by holography revealed that the dissolution of copper was inhibited significantly and no CuCl film formation was found on the surface of the modified film. Sputtering measurements by X-ray photoelectron spectroscopy showed that a small amount of CuCl was formed in the surface layer of the modified film, blocking its micropores, which was probably the reason why copper corrosion was inhibited.