Corrosion Inhibition of 2-Undecyl-N-Carboxymethyl-N- Hydroxyethyl Imidazoline on Carbon Steel in Simulated Seawater Reverse Osmosis Product Water

Abstract

Corrosion inhibition of 2-undecyl-N-carboxymethyl-N-hydroxyethyl imidazoline (UH- CI) on carbon steel in an artificial water, which simulated the water produced by seawater reverse osmosis (RO) process, was investigated by mass loss test, electrochemical methods, and X-ray pho- toelectron spectroscopy (XPS). Results show that UHCI could inhibit the corrosion of carbon steel, and the inhibition efficiency increases with the increasing concentration of UHCI. The UHCI acts as an anodic type inhibitor responsible for reducing the anodic current density. XPS results suggest that UHCI was adsorbed on the mild steel surface, which can effectively protect carbon steel from corrosion in the artificial water. Quantum chemical calculation results reveal that carboxymethyl and the ring of UHCI play the important role when UHCI adsorbed on carbon steel surface, which leads to the enhancement in the corrosion resistance of carbon steel and thereby a reduction in the