Retard the corrosion reaction of carbon steel in acid solutions using Gemini-nonionic surfactant: Theoretical and experimental studies

In the present investigation, a Gemini-nonionic surfactant with hydrophobic tail based on polyethylene glycol (GNs) has been applied to suppress the sever attack of acidic solutions (1 M HCl and 0.5 M H2SO4) on carbon steel (CS) using electrochemical impedance spectroscopy( EIS), weight loss and potentiodynaminc polarization techniques. At room temperature, the corrosion inhibition efficiency of GNs inhibitor increased till touch 75.73% and 86.47% at 50 ppm in 0.5 M H2SO4 and 1 M HCl respectively, demonstrating GNs ability to mitigate CS corrosion. From potentiodynaminc polarization (PDP) examination, GNs compound acted as hybrid corrosion inhibitor. Also, the adsorption of GNs on CS surface followed Langmuir isotherm model and the adsorption free energy (Delta Goads) change were - 29.517 kJmol-1 and - 27.733 kJmol-1 in 1 M HCl and 0.5 M H2SO4, respectively. The CS surface morphology was examined using scanning electron microscope (SEM) and energy dispersive Xray (EDX) and atomic force microscopy (AFM). Theoretical investigations based on density function theory (DFT) and Monte Carlo simulation (MCs) predicted the active centers and the mode of adsorption of GNs.

Automated summary

In this study, a Gemini-nonionic surfactant based on polyethylene glycol (GNs) was used to inhibit the corrosion of carbon steel by acidic solutions. The results showed that GNs effectively reduced the corrosion of carbon steel in 1 M HCl and 0.5 M H2SO4, acting as a hybrid corrosion inhibitor. The adsorption of GNs on the surface of carbon steel followed the Langmuir isotherm model.