Preparation and Analysis of Complex Barrier Layer of Heterocyclic and Long-Chain Organosilane on Copper Alloy Surface

A single electrodeposited film of 6-(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-dithiol monosodium (TES) on a copper alloy surface was prepared by the galvanostatic method, then octyl-triethoxysilane (OTES) or hexadecyl-trimethoxysilane (HDTMS) was used to modify the electrodeposited film by the self-assembled technique to fabricate the complex film. The electrodeposition process was inferred by cyclic voltammetry. The single and complex films were characterized by means of contact angle, cyclic voltammetry, Fourier transform infrared spectroscopy (FT-IR), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). The results showed that the contact angle of the complex film covering the copper alloy surface was up to 118.1° compared with 89.4° of the bare copper alloy. The cyclic voltammogram, polarization curves and EIS indicated that the anti-corrosion performance of complex film was better than that of single electrodeposited TES film, and the protection efficiency was up to 90.2%.Keywords:complex film;cyclic voltammetry;potentiodynamic polarization;anti-corrosion