Synergistic inhibition effect of imidazoline derivative and L-cysteine on carbon steel corrosion in a CO2-saturated brine solution

The corrosion inhibition performance of imidazoline derivative (IM) and L-cysteine (CYS) on carbon steel in CO2-saturated brine solution was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), weight loss, contact angle and X-ray photoelectron spectroscopy (XPS) measurements. The results show that the inhibition performance of individual IM is slight for CO2 induced corrosion, and can be strengthened greatly by combined use with Cys. The synergistic inhibition effect of IM and CYS is observed. An adsorption model involving the initial adsorption of CYS on carbon steel surface followed by IM was proposed to elucidate the synergistic mechanism. (C) 2016 Elsevier Ltd. All rights reserved.