模拟海水淡化一级反渗透产水中咪唑啉缓蚀剂对20#碳钢的缓蚀行为

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

采用失重法、电化学方法、XPS和SEM分析了2-十一烷基-N-羧甲基-N-羟乙基咪唑啉(UHCI)对20#碳钢在模拟海水淡化一级反渗透产水中的缓蚀行为。结果表明:UHCI对20#碳钢具有缓蚀作用,并且随着UHCI浓度的增加,缓蚀效率明显增大;UHCI减小了碳钢电极的阳极电流密度,是一种阳极型缓蚀剂。XPS测试表明,UHCI吸附在金属表面形成保护膜,有效阻碍腐蚀介质向金属表面扩散,从而达到缓蚀效果。量子化学计算结果表明,UHCI分子在与金属作用时,主要是羧甲基和咪唑环吸附在金属表面,从而降低腐蚀速率。

Corrosion inhibition of 2-undecyl-N-carboxymethyl-N-hydroxyethyl imidazoline（UHCI） 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 photoelectron 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 corrosion rate.