Experimental and theoretical research on the corrosion inhibition of 1-octyl-3-methylimidazolium L-prolinate for copper in 3.5% NaCl solution

Abstract

An amino acid ionic liquid, namely 1-octyl-3-methylimidazolium L-prolinate ([OMIM]L-pro), was investigated as the corrosion inhibitor of copper in 3.5% NaCl solution through electrochemical techniques, surface analysis and molecular dynamics simulation. The results showed that [OMIM]L-pro was a mixed type inhibitor with a predominantly anodic action for copper in NaCl solution, its inhibition efficiency increased with the increase of concentration, but decreased with rising temperature, the highest inhibition efficiency was up to 97.5%. The adsorption of [OMIM]L-pro on the copper surface was found to follow the Langmuir isothermal equation, and the corrosion kinetic characteristics of copper in the test solution was discussed and analyzed. Moreover, L-prolinate anion was found to play a significant role in the corrosion inhibition performance of [OMIM]L-pro, but there was a synergistic effect between L-prolinate anion and imidazolium cation, which synergistically inhibited the corrosion of copper in NaCl solution. Molecular dynamics simulation data supported the experimental results.

Keywords:

• Copper
• corrosion inhibitor
• 1-octyl-3-methylimidazolium L-prolinate
• adsorption
• synergistic effect
• electrochemical investigation
• molecular dynamics simulation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by financially by Graduate Innovation Fund Project of Sichuan University of Science & Engineering [No. y2020052], the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan Province [No. 2019CL02], the National Natural Science Foundation of China [NO. 22062022], and the Foundation of the Department of Science and Technology of Guizhou province [QKHPTRC[2021]5643].