Electrochemical and XPS studies of alkyl imidazoline on the corrosion inhibition of carbon steel in citric acid solution
AbstractThe corrosion inhibition behavior of an imidazoline derivative, namely, 2-undecyl-N-carboxymethyl-N-hydroxyethyl imidazoline (UHCI) for carbon steel in 4 wt.% citric acid solutions was characterized by weight loss method and electrochemical techniques in conjunction with X-ray photoelectron spectrometer (XPS) technique. The inhibitor has a good anti-corrosion effect on the carbon steel in 4 wt.% citric acid solutions. The inhibition efficiency increases with UHCI concentrations from 0 up to 0.4 wt.%, yet declines a bit at 0.6 wt.% per contra with further augmentation of concentration. The inhibition efficiency declines with the rise of temperature from 20°C to 95°C, while it rises with the extension of soaking time from 2 h to 24 h. Two N1s peaks that appeared in XPS spectra give proof of UHCI inhibitor adsorbed on the carbon steel surface.