Self-assembled 1-octadecyl-1H-benzimidazole film on copper surface for corrosion protection

Films of 1-octadecyl-1H-benzimidazole (OBI) have been formed on copper surface by selfassembly method. Optimum conditions viz. the solvent, concentration of OBI, immersion period and temperature for the formation of a protective film on copper have been established using impedance studies. The OBI film has been characterized by X-ray photoelectron spectroscopy, reflection absorption Fourier transform infrared (FTIR) spectroscopy, contact angle measurements and atomic force microscopy. Efficiency of the OBI film to protect copper from corrosion has been investigated in aq. HCl solution using electrochemical impedance spectroscopy, potentiodynamic polarization method, cyclic voltammetry, scanning electronmicroscopy and gravimetry. Results of these studies inferred that the OBI film has an inhibition efficiency in the range of 97-99% under different conditions. Polarization studies inferred that the OBI film functions as a cathodic inhibitor. Cyclic voltammetric studies showed that the film is stable even after 15 cycles, when the copper electrode is polarized to an anodic potential of 0.35V vs. Ag/AgCl electrode. © Indian Academy of Sciences.