AEO7 Surfactant as an Eco-Friendly Corrosion Inhibitor for Carbon Steel in HCl solution

Abstract

The impact of AEO7 surfactant on the corrosion inhibition of carbon steel (C-steel) in 0.5 M HCl solution at temperatures between 20 °C and 50 °C was elucidated using weight loss and different electrochemical techniques. The kinetics and thermodynamic parameters of the corrosion and inhibition processes were reported. The corrosion inhibition efficiency (IE%) improved as the concentration of AEO7 increased. In addition, a synergistic effect was observed when a concentration of 1 × 10−3 mol L−1 or higher of potassium iodide (KI) was added to 40 µmol L−1 of the AEO7 inhibitor where the corrosion IE% increased from 87.4% to 99.2%. Also, it was found that the adsorption of AEO7 surfactant on C-steel surface followed the Freundlich isotherm. Furthermore, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements indicated that AEO7 was physically adsorbed on the steel surface. The surface topography was examined using an optical profilometer, an atomic force microscope (AFM), and a scanning electron-microscope (SEM) coupled with an energy dispersion X-ray (EDX) unit. Quantum chemical calculations based on the density functional theory were performed to understand the relationship between the corrosion IE% and the molecular structure of the AEO7 molecule.

Synthesis of ZnO-NPs Using a Convolvulus arvensis Leaf Extract and Proving Its Efficiency as an Inhibitor of Carbon Steel Corrosion

“…The carbon steel electrodes were immersed for up to 3 h at temperatures of either 298 and 333 K. Figure 3 illustrates that the inhibition efficiency and degree of surface coverage increases with an increase in the inhibitor concentration and becomes stable after a concentration of 0.06 mg/mL. The results are shown in Table 1, which demonstrate that the anodic and cathodic reactions are controlled by the inhibitor molecules being adsorbed on the active sites of the carbon steel surface; thus, the surface becomes saturated with the ZnO-NPs, forming a protective layer that prevents the continuation of corrosion [4,6,7].…”

“…The carbon steel electrodes were immersed for up to 3 h at temperatures of either 298 and 333 K. Figure 3 illustrates that the inhibition efficiency and degree of surface coverage increases with an increase in the inhibitor concentration and becomes stable after a concentration of 0.06 mg/mL. The results are shown in Table 1, which demonstrate that the anodic and cathodic reactions are controlled by the inhibitor molecules being adsorbed on the active sites of the carbon steel surface; thus, the surface becomes saturated with the ZnO-NPs, forming a protective layer that prevents the continuation of corrosion [4,6,7]. Figure 4 illustrates the potentiodynamic polarization curves for both the anodic and cathodic Tafel behavior of carbon steel corrosion in 1 M HCl in the absence and presence of different concentrations of the inhibitor at temperatures of 298 and 333 K. The Tafel slopes show that the addition of an inhibitor influences both anodic and cathodic reactions, leading to the conclusion that the effect of ZnO-NPs inhibitors is of a mixed type.…”

“…Hydrochloric acid is used in many metallurgical industries, oil refineries, chemical and electrochemical processes, pickling metals, and the cleaning of some devices. The high concentrations of acid can affect the equipment and devices, causing severe corrosion [2,3]; this can affect the strength of materials, the environment, and the safety of society if no precautionary measures are taken to prevent or control it [4]. The corrosion of carbon steel may be present in different forms, such as uniform corrosion, galvanic corrosion, pitting corrosion, crevice corrosion, stress corrosion cracking, erosion corrosion, and microbial corrosion, among others.…”

Electrochemical and thermodynamic study on the corrosion performance of API X120 steel in 3.5% NaCl solution

“…It could be noticed from Fig. 3A that the corrosion rate decreases as the PEI corrosion inhibitor concentration increases, suggesting that a greater number of PEI molecules are adsorbed over the active sites of the metal surface hence diminishing the direct contact between the API X120 steel and the corrosive environment 31,42 .…”

The Sorption Performance of Cetyl Trimethyl Ammonium Bromide-Capped La0.9Sr0.1FeO3 Perovskite for Organic Pollutants from Industrial Processes

“…Surfactants and their composites can be used for water and wastewater decontamination, where they can be used to remove oppositely charged toxic metal ions and organic compounds via strong electrostatic attractions [6][7][8]. They can also be used for the corrosion protection of metals that can from an oxide layer, where surfactants can be adsorbed onto the oxide layer, providing a protective coating for the metal [9][10][11]. Surfactants were also used to improve the electrochemical sensing performance of many compounds and drugs [12][13][14][15] and catalytic processes [16][17][18][19][20].…”