Corrosion protection of copper with 3-glycidoxypropyltrimethoxysilane-based sol-gel coating through 3-amino-5-mercapto-1,2,4-triazole doping

In this work, 3-amino-5-mercapto-1,2,4-triazole (AMTa) was incorporated into 3-glycidoxypropyltrimethoxysilane (GPTMS)-based sol-gel coatings, which were self-assembled over a copper surface. The AMTa-doped GPTMS-based sol-gel coatings were characterized by Fourier transform infrared spectroscopy, Scanning Electron Microscopy, and Energy-Dispersive X-ray spectroscopy analyses. The protective ability of these coatings was evaluated by electrochemical impedance studies and potentiodynamic polarization measurements in 3.5 % NaCl medium. The AMTa-doped sol-gel coating showed enhanced corrosion protection ability compared to the un-doped GPTMS-based sol-gel coating, which may be largely due to the formation of thiolate bonds between copper and AMTa. The presence of a silane network through the amine group of AMTa could also be a reason for the enhanced protection.