Efficient Complex Surfactants from the Type of Fatty Acids as Corrosion Inhibitors for Mild Steel C1018 in CO₂-Environments

Abstract

ABSTRACT. The efficiency of three complex surfactants based on sunflower oil and nitrogen containing compounds as corrosion inhibitors for mild steel in CO2-saturated 1% NaCl solution, has been determined by weight loss and LPR corrosion rate measurements. These compounds inhibit corrosion even at very low concentrations. The inhibition process was attributed to the formation of an adsorbed film on the metal surface that protects the metal against corrosive media. The inhibition efficiency increases with increasing the concentration of the studied inhibitors. Maximum inhibition efficiency of the surfactants is observed at concentrations around its critical micellar concentration (CMC). Adsorption of complex surfactants on the mild steel surface is in agreement with the Langmuir adsorption isotherm model, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. Energy dispersive X-ray fluorescence microscopy (EDRF) observations of the electrode surface confirmed the existence of such an adsorbed film.

Novel naphthenate surfactants based on petroleum acids and nitrogenous bases as corrosion inhibitors for C1018-type mild steel in CO2-saturated brine

“…The ability of a surfactant molecule to adsorb is generally related to its ability to aggregate to form micelles. Surfactants have been used for the corrosion inhibition of carbon steel in CO 2 environments [14][15][16][17].…”

Enhanced corrosion inhibition of mild steel in CO2-saturated solutions containing some novel green surfactants based on cottonseed oil

“…The CMC is the concentration where surfactants in solution change their initial molecular solvated state [6]. At this concentration, physical and chemical properties exhibit an abrupt variation.…”

“…The use of inhibitors is one of the most practical methods for protection against corrosion [6][7][8][9][10]. To be effective, an inhibitor must also transfer water from the metal surface, interact with anodic or cathodic reaction sites to retard the oxidation and reduction corrosion reaction, and prevent transportation of water and corrosion-active species on the metal surface.…”

Inhibitive Effect of Some Natural Naphthenates as Corrosion Inhibitors on the Corrosive Performance of Carbon Steel in CO2-Saturated Brine

“…A molecular layer of surfactants is formed as a result of this attraction with the construction of a hydrophobic barrier, which prevent the contact of the metal surface with the environment. The surfactant inhibitors have many advantages such as high inhibition efficiency, low price, low toxicity and easy production (Abbasov et al, 2013a;Abbasov et al, 2013b;Abd El-Lateef et al, 2012a;Stoyanova et al, 1997;Abdallah et al, 2009;Joseph and Rajendran, 2001). The adsorption of the surfactant on the metal surface can markedly change the corrosion-resisting property of the metal (Abd El-Lateef et al, 2012b), and so the study of the relationship between the adsorption and corrosion inhibition is of great importance.…”