Parametric study on the electrochemical impedance spectroscopy of organic-coated steels in hydrochloric acid solutions

2003 ◽  
Vol 75 (6) ◽  
pp. 65-72 ◽  
Author(s):  
K. M. Yin ◽  
L. I. Lu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Hydrochloric Acid ◽  
Impedance Spectroscopy ◽  
Parametric Study ◽  
Electrochemical Impedance ◽  
Acid Solutions ◽  
Hydrochloric Acid Solutions

scholarly journals New triazepine carboxylate derivatives: correlation between corrosion inhibition property and chemical structure

2020 ◽  
Vol 11 (1) ◽  
pp. 23-42 ◽  
Author(s):  
K. Alaoui ◽  
Y. El Kacimi ◽  
M. Galai ◽  
H. Serrar ◽  
R. Touir ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Hydrochloric Acid ◽  
Impedance Spectroscopy ◽  
Mild Steel ◽  
Acid Medium ◽  
Corrosion Inhibition ◽  
Electrochemical Impedance ◽  
Protective Film ◽  
Hydrochloric Acid Medium ◽  
Inhibition Property

AbstractIn this investigation, attempts have been made to study the corrosion inhibition properties of three new triazepine carboxylate compounds for mild steel in 1.0 M hydrochloric acid medium. The evaluation was carried out using mass loss, electrochemical impedance spectroscopy and polarization curves measurement. Impedance diagrams and Bode plots for uninhibited and inhibited systems were analyzed using Zview program. The fitted data observed trails in nearly the same pattern as the experimental results. It is showed that triazepine carboxylate compounds are very good inhibitors for mild steel corrosion in 1.0 M hydrochloric acid medium which act as mixed-type inhibitors. So, the inhibition efficiency was increased with inhibitor concentration in the order Cl–Me–CN > Me–CN > Cl–Me–CO2Et which depended on their molecular structures. Electrochemical impedance spectroscopy showed that all compounds act by the formation of a protective film at the metal surface. Surface analyses via SEM and Optical 3D profilometry were used to investigate the morphology of the steels before and after immersion in 1.0 M HCl solution containing inhibitors. The correspondence between inhibition property and molecular structure of the triazepine carboxylate compounds was investigated, using density functional theory (DFT). Experimental and DFT study was further supported by molecular dynamic simulations study.

scholarly journals Acetylcholine and Rivastigmine as Corrosion Inhibitors of Cu – Sn - Zn – Pb Alloy in Hydrochloric Acid Environment: DFT & Electrochemical Approach

2021 ◽  
Vol 25 (8) ◽  
pp. 1441-1448
Author(s):  
B.U. Ugi ◽  
V.M. Bassey ◽  
M.E. Obeten ◽  
S.A. Adalikwu ◽  
E.C. Omaliko ◽  
...  
Keyword(s):  
Weight Loss ◽  
Electrochemical Impedance Spectroscopy ◽  
Hydrochloric Acid ◽  
Impedance Spectroscopy ◽  
Potentiodynamic Polarization ◽  
Corrosion Inhibitors ◽  
Electrochemical Impedance ◽  
Transfer Resistance ◽  
Electrochemical Approach ◽  
Acid Environment

The study on the action of Acetylcholine and Rivastigmine as Corrosion Inhibitors of Cu – Sn - Zn – Pb Alloy in Hydrochloric Acid Environment was carried out using density functional theory, electrochemical impedance spectroscopy, Potentiodynamic polarization, Scanning electron microscopy and weight loss. The result revealed that both Acetylcholine and Rivastigmine expired drugs were good inhibitors of Cu – Sn - Zn – Pb Alloy in Hydrochloric Acid Environment. This was confirmed from results of weight loss (99.1 % and 95.0 %), electrochemical impedance spectroscopy (EIS) (92.5 % and 91.8 %), and Potentiodynamic polarization (97.4 % and 87.1 %). Both inhibitors were able to increase the charge transfer resistance and corrosion current densities of the electrical solution and reduce the double layer capacitance of the metal – solution interface. Inhibition was as a result of adsorption of inhibitor molecules on the Cu – Sn - Zn – Pb surface. Thermodynamically, inhibitors showed greater stability on metal surface, spontaneous in the forward direction and reduction in level of disorderliness. Inhibitors demonstrated a mixed type inhibition while physical adsorption mechanism was proposed for the inhibitor – metal interaction. Langmuir adsorption isotherm was obeyed as data fitted adequately to the isotherm and regression coefficient was approximately unity. A monolayer adsorption was deduces.

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