Cationic clevelable surfactants as highly efficient corrosion inhibitors of stainless steel AISI 304: Electrochemical study

The corrosion inhibition efficiency of three cationic clevelable surfactants with different chain length on AISI 304 stainless steel in 3 M HCl was investigated by polarisation measurements and electrochemical impedance spectroscopy (EIS). The surface of the samples was characterized before and after the corrosion experiments using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results showed that the effectiveness of corrosion inhibition depends on chain length. In the present study, the Langmuir adsorption isotherm was found to be suitable parameter for the correlating the experimental results with a possible mechanism of protection. In the case of tested compounds the highest inhibition efficiency was found around the critical micelle concentration. Critical micelle concentration (CMC) was determined using conductometric titration. (C) 2020 Elsevier B.V. All rights reserved.