scholarly journals Cation Effect in the Corrosion Inhibition Properties of Coumarate Ionic Liquids and Acrylic UV-Coatings

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2611
Author(s):  
Esther Udabe ◽  
Anthony Sommers ◽  
Maria Forsyth ◽  
David Mecerreyes

Chromate free corrosion inhibitors are searched for to mitigate the economic loss caused by mid-steel corrosion. Here, we show metal-free organic inhibitors having free coumarate anions that can be used either as direct corrosion inhibitors or incorporated into a polymer coating obtained by UV-curing. Four different ionic liquid monomers and polymer coatings with hexoxycoumarate anion and different polymerizable counter cations were investigated. Potentiodynamic polarization, electrochemical impedance spectroscopy, and surface analyses have verified their corrosion inhibition performance on a mild steel AS1020 surface. In the case of the coumarate ionic liquid monomers, the most promising inhibitor is the one coupled with the ammonium cation, showing an inhibition efficiency of 99.1% in solution followed by the imidazolium, pyridinium, and anilinium. Next, the ionic liquid monomers were covalently integrated into an acrylic polymer coating by UV-photopolymerization. In this case, the barrier effect of the polymer coating is combined with the corrosion inhibitor effect of the pendant coumarate anion. Here, the best polymer coatings are those containing 20% imidazolium and pyridinium cations, presenting a greater impedance in the EIS (Electrochemical Impedance Spectroscopy) measurements and less evidence of corrosion in the scribe tests. This article shows that the cationic moiety of coumarate based ionic liquids and poly(ionic liquid)s has a significant effect on their excellent corrosion inhibition properties for a mild steel surface exposed to aqueous chloride solutions.

2013 ◽  
Vol 750-752 ◽  
pp. 2258-2262 ◽  
Author(s):  
Wei Ming Wu ◽  
Ding Li ◽  
Hai Yan Du

The experiments were done to find some good corrosion inhibitors for mild steel in 5% HF solution by the method of weight loss and electrochemistry including polarization curves and electrochemical impedance spectroscopy (EIS). Results show that the thiourea, potassium thiocyanate, and hexamethylenetetramine have good inhibition effect for mild steel in 5% HF solution, especially potassium thiocyanate and thiourea. Their corrosion resistance was greatly enhanced in the presence of tested inhibitor. Thiourea is an anodic type inhibitor and its inhibition efficiencies up to 99.88% can be obtained. Equivalent circuit of the investigated system was suggested.


Author(s):  
Moussa Ouakki ◽  
Mouhsine Galai ◽  
Mohammed Cherkaoui ◽  
Mohamed Ebn Touhami ◽  
E. H. Rifi ◽  
...  

The corrosion inhibition of mild steel in hydrochloric, sulfuric, and phosphoric acids solutions containing a mineral compound-based phosphate (apatite) was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy. Potentio-dynamic polarization measurements reveal that the inhibition efficiency increased with the concentration of the apatite, which appears to be a cathodic type inhibitor in the three mediums. Electrochemical impedance spectroscopy confirms this result; indeed, the transfer resistance increases with apatite concentration. The authors note that the double layer capacitance decreases simultaneously suggesting the formation of an adsorbed layer on the mild steel surface. The inhibition mechanism has been elucidated by a thermodynamic study, which showed that the film was formed by physi-sorption. The adsorption model obeys to the Langmuir adsorption isotherm. The parameters of activation energy were evaluated and discussed.


2011 ◽  
Vol 415-417 ◽  
pp. 174-177
Author(s):  
Yu Qiu Huo ◽  
Ling Bai

Manganese ions doped Pani films were prepared by using a cyclic voltammetry technique on mild steel substrate. Corrosion resistances performances of them in 0.5 M H2SO4 solution were obtained by using electrochemical impedance spectroscopy (EIS), polarization curve, and SEM method. The results showed that manganese ions doped Pani particles became smaller and tighter, the resistance reduced, and the corrosion potential rose than Pani in H2SO4 solution.


2020 ◽  
Vol 11 (1) ◽  
pp. 23-42 ◽  
Author(s):  
K. Alaoui ◽  
Y. El Kacimi ◽  
M. Galai ◽  
H. Serrar ◽  
R. Touir ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Nimmy Kuriakose ◽  
Joby Thomas Kakkassery ◽  
Vinod P. Raphael ◽  
Shaju K. Shanmughan

The corrosion inhibition efficiency of thiophene-2-carbaldehyde tryptophan (T2CTRY) on mild steel (MS) in 1 M HCl solution has been investigated and compared using weight loss measurements, electrochemical impedance spectroscopy, and potentiodynamic polarization analysis. The Schiff base exhibited very good corrosion inhibition on mild steel in HCl medium and the inhibition efficiency increased with the increase in concentration of the inhibitor. The adsorption of the inhibitor on the surface of the corroding metal obeys Freundlich isotherm. Thermodynamic parameters (Kads, ΔG ads0) were calculated using adsorption isotherm. Polarization studies revealed that T2CTRY acts as a mixed type inhibitor. A maximum of 96.2% inhibition efficiency was achieved by EIS studies at a concentration of 1 mM.


Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 675 ◽  
Author(s):  
Mohammad A. Jafar Mazumder

The zwitterionic monomers, N,N’-diallylamino propanephosphonate and amino acid residual N,N’-diallyl-l-methionine hydrochloride were synthesized, with excellent yields. These monomers were utilized in the preparation of zwitterionic homo and co-cyclopolymers 5–7 in aqueous solution using 2,2′-azobis (2-methylpropionamidine) dihydrochloride as an initiator. The polymers were characterized by FT-IR, NMR, and TGA. The performance of these synthesized polymers on mild steel in acidic solution was investigated by gravimetric method, Tafel extrapolation, linear polarization resistance, and electrochemical impedance spectroscopy. At 313 K, the maximum inhibition efficiencies of corrosion inhibitors 5–7 at 4.50 × 10−4 mol L−1 were found to be 85.2%, 83.3%, and 99.5%, respectively. The inhibition efficiencies obtained from gravimetric weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy measurements were in good agreement. Different adsorption isotherms were also explored to find the best fit, and found to obey Langmuir adsorption isotherm. The thermodynamic parameters, such as activation energy (Ea), standard enthalpy of activation (ΔH*), standard entropy of activation (ΔS*), adsorption–desorption equilibrium constant (Kads), and standard free energy of adsorption (ΔGoads), were determined. Electrochemical data indicated that the zwitterionic copolymer 7 acts as a mixed type inhibitor under the influence of anodic control. The surface morphology of mild steel corrosion was evaluated without and with corrosion inhibitors by AFM, SEM-EDX, and XPS, which confirmed the adsorption of inhibitor molecules on the metal surface.


2011 ◽  
Vol 194-196 ◽  
pp. 44-51
Author(s):  
Fei Ran Xu ◽  
Sheng Tao Zhang ◽  
Xiao Li

The corrosion inhibition of 45# mild steel in 3%HCL solution by norfloxacin has been studied by weight loss measurement, Tafel polarization, electrochemical impedance spectroscopy (EIS) and quantum chemical study. The inhibitor of norfloxacin shows 93.2% inhibition efficiency at optimum concentration 400mg/L. The polarization studies suggest that norfloxacin is the mixed-type inhibitor for 45# carbon steel in 3%HCL. Electrochemical impedance spectroscopy techniques are also used to investigate the mechanism of corrosion inhibition. What is more, the adsorption model obeys Langmuir adsorption isotherm at 298K. And the calculated quantum chemical also suggests that norfloxacin have excellent inhibition properties.


RSC Advances ◽  
2021 ◽  
Vol 11 (41) ◽  
pp. 25314-25333
Author(s):  
Mai A. Khaled ◽  
Mohamed A. Ismail ◽  
Ahmed. A. El-Hossiany ◽  
Abd El-Aziz S. Fouda

This study targets the investigation of three pyrimidine derivatives (MA-1230, MA-1231, MA-1232) for the prevention of corrosion on copper in 1 M HNO3via weight loss (WL), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) techniques.


2010 ◽  
Vol 114 (34) ◽  
pp. 14627-14634 ◽  
Author(s):  
Ichiroh Takeuchi ◽  
Kinji Asaka ◽  
Kenji Kiyohara ◽  
Takushi Sugino ◽  
Ken Mukai ◽  
...  

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