Anticorrosion Effect of Ethoxylate Sulfanilamide Compounds on Carbon Steel in 1 M Hydrochloric Acid: Electrochemical and Theoretical Studies

Abstract

Metal corrosion is an important economic problem globally. One of the best ways to protect metal surfaces from corrosion is by the use of corrosion inhibitors, especially surfactants. This study assesses anticorrosion properties of three inhibitor compounds (S1, S2, and S3) of ethoxylate sulfanilamide containing 2, 10, and 20 units of ethylene oxide on carbon steel in 1 M HCl solution. The anticorrosive performance of S1, S2, and S3 was studied using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), adsorption isotherm, surface tests (scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) analysis), and computational studies (density functional theory (DFT) and molecular dynamics (MD) simulations) within the concentration range of 10 –6 to 10 –2 M at 30 ± 2 °C. The results of the methods used indicate that increasing the concentration of the inhibitor compounds improves the effectiveness of inhibition (from 50.9 to 98%), whereas the inhibition efficiency order for ethoxylated sulfanilamide compounds is S2 > S3 > S1 with the highest inhibiting efficiency, respectively, of 98.0, 95.0, and 90.0% for 10 –2 M. Also, PDP indicated that S1, S2, and S3 inhibitors act as mixed-type inhibitors and their adsorption obeys the Langmuir adsorption isotherm model. Surface tests show that the studied compounds can significantly inhibit acid attack via chemical adsorption on the metal. Furthermore, all of the chemical descriptors derived from DFT indicate that the three inhibitors are quite well adsorbed by the adhesion centers on the CS surface. The three compounds’ molecular geometries and electronic structures were calculated using quantum chemical calculations. Using theoretical computations, the energy difference between the highest occupied molecular orbital and the lowest occupied molecular orbital has been determined to represent chemical reactivity and kinetic stability of a composition.

Synergetic Anticorrosion Mechanism of Main Constituents in Chinese Yam Peel for Copper in Artificial Seawater

“…The fitted results, namely, the corrosion current density ( i corr‑f ), causality factors (CF2 and CF3), and anodic (β a ) and cathodic (β c ) Tafel slopes, are summarized in Figure . In Figure a, CF2 and CF3 close to the ideal magnitudes (2 and 3, respectively) indicate the satisfactory causality between the input frequency perturbation and the signal response . Similar to the results derived from polarization measurements, i corr‑f persistently declines with the increase in CYPE concentration due to the constituent adsorption at the copper/electrolyte interface.…”

“…In Figure 8a, CF2 and CF3 close to the ideal magnitudes (2 and 3, respectively) indicate the satisfactory causality between the input frequency perturbation and the signal response. 42 Similar to the results derived from polarization measurements, i corr-f persistently declines with the increase in CYPE concentration due to the constituent adsorption at the copper/electrolyte interface. In Figure 8b, i corr-f is reduced to 1.811 μA/cm 2 , when the concentration of CYPE attains 900 mg/L, yielding the highest IE f .…”

Corrosion mitigation for steel in acid environment using novel p-phenylenediamine and benzidine coumarin derivatives: synthesis, electrochemical, computational and SRB biological resistivity

“…The calculated and K ads values for all adsorption isotherm models are listed in Table 6 at 298 K. Spontaneous nature of adsorption and stability of the adsorbed layer are expected for the studied organic derivatives towards the electrode metal surface due to the negative calculated values for . Based on previously accepted research, 69,70 the spontaneous adsorption behavior is a steady process that cannot be reversed. The adsorption process behavior depends on the values: physisorption if ≥ −20 kJ mol −1 , chemisorption if ≥ −40 kJ mol −1 and mixed type if values are between −20 and −40 kJ mol −1 .…”

“…The calculated DG ads and K ads values for all adsorption isotherm models are listed in Table 6 at 298 K. Spontaneous nature of adsorption and stability of the adsorbed layer are expected for the studied organic derivatives towards the electrode metal surface due to the negative calculated values for DG ads . Based on previously accepted research, 69,70 the spontaneous adsorption behavior is a steady process that cannot be reversed. The adsorption process behavior depends on the DG The DG ads results are −36.10, −36.18 and 36.15 kJ mol −1 for PhODB, BODB and DODB, respectively, according to the Langmuir adsorption model, so the adsorption of these compounds on MS surfaces are of mixed type (physisorption and chemisorption, but mainly chemical).…”

Engineering Advanced Environmentally Friendly Corrosion Inhibitors, Their Mechanisms, and Biological Effects in Live Zebrafish Embryos

“…8 Certain structural features that are common to most effective corrosion inhibitors should be included in the design of new compounds, such as heterocyclic character, the inclusion of N and O heteroatoms, and the presence of polar functional groups such as hydroxyl, carboxylate, and conjugated π-electrons, 7,9 as these all have an affinity toward the metallic surface. 10,11 Surfactants are amphiphilic molecules with applications in different areas including pharmaceuticals, the food industry, and cosmetics. 12 Cationic surfactants such as cetyltrimethylammonium bromide (CTAB) are quaternary ammonium salts with their antimicrobial surface-active properties.…”