Electrochemical and Surface Characterization Study on the Corrosion Inhibition of Mild Steel 1030 by the Cationic Surfactant Cetrimonium Trans-4-hydroxy-cinnamate

Abstract

Effective corrosion inhibition of mild steel 1030 at 0.01 M NaCl concentration was achieved by the use of the nontoxic surfactant salt cetrimonium trans-4-hydroxy-cinnamate (CTA-4OHcinn). Polarization analysis on the steel samples immersed for 24 h in the control and CTA-4OHcinn-containing solutions shows the development of a passivation potential that is more obvious at higher inhibitor concentrations along with a maximum inhibition efficiency of 97.8%. Electrochemical impedance spectroscopy (EIS) pinpoints the effect of the inhibitor on the corroding regions of the metal surface, showing an increase in the local electric resistance and conversely a decrease in the local capacitance, which indicates that the charge transfer in the corroding regions is being hindered by a deposition process. This is consistent with scanning electron microscopy (SEM) images, showing the presence of a porous oxide matrix that fills localized corrosion sites on the metal surface after 24 h of immersion in a 0.01 M NaCl + 10 mM inhibitor solution. Additionally, SEM analysis also shows the formation of an organic film surrounding the defects that is able to shield chloride attack. As a result of diffusion of chloride from the defects below the protective film, filiform corrosion can be seen. Time-resolved impedance analysis over the first 120 min of immersion in the control and inhibitor solution shows that significant inhibitor protection does not take place immediately and there is a lag phase in the first 50 min of immersion, suggesting that early localized corrosion drives further adsorption of inhibitor micelles on the metal surface. This is in agreement with X-ray photoelectron spectroscopy (XPS) analysis, which indicates a complete surface coverage over the first 2 h of immersion in a concentrated inhibitor solution. XPS also shows the heterogeneity of the film, where some parts are poorly covered, revealing the underlying surface containing iron.

Corrosion resistance of NbN and NbxAlyN coatings on stainless steel

“…In the proposed circuit, R s is the electrolyte resistance, CPE dl is the capacitance at the coating-substrate interface, R ct is the charge transfer resistance, CPE coat is the coating capacitance and R po is the coating pore resistance. In order to take into consideration surface heterogeneities, constant phase elements were employed in substitution of pure capacitances [27,28]. Table 2 shows the fitted parameters and their respective variances.…”

One-Pot Hydrothermal Synthesized Nitrogen and Sulfur Codoped Carbon Dots for Acid Corrosion Inhibition of Q235 Steel

“…The high-resolution spectrum of Fe 2p 3/2 has peaks of Fe, FeO, and Fe 2 O 3 /FeOOH at 706.73, 710.18, and 711.88 eV. 39 The spectrum of C 1s has three peaks of CS/CO, CN, and CC/CN, at 287.78, 285.83, and 284.48 eV, respectively. 40,41 The O 1s spectrum presented peaks at 529.38, and 530.88 eV, which are assigned respectively to Fe 2 O 3 /Fe 3 O 4 and FeOOH.…”

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

“…15,16 Recently, it has been reported that some organic compounds based on trans-4-hydroxy-cinnamate are nontoxic materials 17 with highly effective corrosion inhibition properties. 18,19 Herein, we reveal that by substitution of an ethoxy group on trans-4-hydroxy-cinnamate there is a significant improvement in the inhibition properties of this organic molecule. Furthermore, previous works in our group have shown that the speciation of CIs plays a critical role in identifying the correlation of the CI structure with the efficiency.…”

“…20 The combination of a quaternary ammonium (CTA − ) with a designed OCI would result in possible micellar formation, as we have discussed previously. 4,19 Here, we use 24 h potentiodynamic polarization (PP) studies and electrochemical impedance spectroscopy (EIS) to determine the effect of structure and concentration on corrosion inhibition. pfg NMR diffusion measurements, molecular dynamic (MD) simulations, and Cryo-TEM are also utilized to investigate the molecular behavior and possible micelle structure with concentration and how these relate to the corrosion inhibition.…”