Evaluation of corrosion inhibition performance of a novel ionic liquid based on synergism between cation and anion

Abstract

A novel ionic liquid, 1-butyl-1H-imidazol-1-ium 3-carboxy-2-((2-carboxylatoethyl)thio)propanoate ([Bhim]CETSA), was synthesized as an environmentally friendly and efficient corrosion inhibitor, and its corrosion inhibition performance on A3 steel in 1 M HCl solution was investigated by using the weight loss method, and the results indicated that the inhibition efficiency reached up to 90.11% when the concentration of [Bhim]CETSA was 10 mM at 298 K. There was a synergistic effect between anion and cation, and the anion played a major role in the corrosion inhibition of [Bhim]CETSA. The adsorption of ionic liquid on the A3 steel surface followed a Langmuir adsorption model and was proved by using infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the relevant thermodynamic parameters were calculated and discussed. Moreover, the existence of the hydrophobic film on the A3 steel was proven by contact angle measurement, and the corrosion inhibition mechanism of [Bhim]CETSA was further studied by quantum chemical calculation.