Development of different chain lengths ionic liquids as green corrosion inhibitors for oil and gas industries: Experimental and theoretical investigations

Three corrosion inhibitors with different anionic carbon chains were investigated: 1-(2-methoxy-2-oxoethyl)-3-methylimidazolium bromide (ILR1), 1-(2-ethoxy-2-oxoethyl)-3-methylimidazolium bromide (ILR2), and 1-(2-propoxy-2-oxoethyl)-3-methylimidazolium bromide (ILR3). The corrosion inhibition performance of ILR1, ILR2, and ILR3 on A1010 steel in 1 M HCl at 298 K was examined using electrochemical experiments, weight loss measurements, Fourier transform infrared spectroscopy coupled with attenuated total reflectance, atomic force microscopy, scanning electron microscopy, and theoretical computations. The synergistic action of bromide ions is used in conjunction with three mixed-type inhibitors with high inhibitory effectiveness. The order of corrosion resistance is ILR1 < ILR2 < ILR3, which is based on practical and theoretical research that demonstrates that the inhibitory action improves with the length of the alkyl chain attached to the imidazolium ring. At an optimum inhibitor concentration of 1 mM/L, ILR1, ILR2, and ILR3 show 90 %, 92 %, and 95 % inhibition efficiency, respectively. Three inhibitors were adsorbed in accordance with the Langmuir adsorption isotherm, including physisorption and chemisorption.