Electrochemical behavior of AgCu50 in alkaline media in the presence of chlorides and 2-mercaptobenzothiazole

Electrochemical behavior of an alloy AgCu50, pure copper, and pure silver, respectively, was investigated by measuring the open circuit potentials using anodic potentiodynamic polarization and potentiostatic method in 0.1 moldm-3 NaOH + 0.02 moldm-3 NaCl solution, without and with adding 2-mercaptobenzothiazole in various concentrations (0.00001 - 0.001 moldm-3). Anodic polarization curves for AgCu50 alloy, showed four current peaks. Potentiostatic curves showed that values of the stationary current densities drop down with the increase of 2-mercaptobenzothiazole concentration in the electrolyte. The electrode surface was analyzed by optical microscopy after the potentiostatic oxidation. Micrographs confirmed that 2-mercaptobenzothiazole has got the inhibitory effect by forming the film of CuMBT and AgMBT which protect the electrode surface from corrosion.

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Electrochemical behavior of Ag-Cu alloy in alkaline media

Hemijska industrija ◽

10.2298/hemind100114005g ◽

2010 ◽

Vol 64 (2) ◽

pp. 105-110 ◽

Cited By ~ 3

Author(s):

Vesna Grekulovic ◽

Mirjana Rajcic-Vujasinovic ◽

Zoran Stevic

Keyword(s):

Electrochemical Behaviour ◽

Pure Copper ◽

Alkaline Media ◽

Alkaline Solutions ◽

Cyclic Voltammograms ◽

Pure Silver ◽

Cu Alloy ◽

Current Densities ◽

Wide Potential

Results of the investigation of electrochemical behaviour of Ag-Cu alloy containing 50 mass% Ag and 50 mass% Cu are presented in this paper. Pure silver and copper were investigated, too. Working electrodes were prepared by metallurgical process. 1 mol dm-3 and 0.5 mol dm-3 solutions of NaOH are chosen as the electrolyte. On the cyclic voltammograms, some current waves corresponding to number and quantity of phases present in the investigated electrodes appeared and they can be used for characterization of investigated alloy. On the voltammogram recorded for pure silver, two anodic and two cathodic peaks appeared. First peak consisted of two joined current waves which can be ascribed to the formation of the two different types of silver(I) oxide, Ag2O. Second peak should correspond to the formation of silver(II) oxide, AgO. Voltammogram obtained for pure copper exhibits one broad current wave corresponding to the formation of copper oxides, followed by a wide potential area in which copper is completely passive. At 0.4 V vs. SCE, current starts to increase again due to oxygen evolution and probably due to simultaneous dissolution of copper with formation of CuO22- as a product. In alkaline solutions copper has no significant influence on the shape and current values of the voltammograms recorded for Ag-Cu alloy; however, it has an influence only on the anodic and cathodic peak potentials, which are shifted to more negative values in comparison to Ag. It could mean an easier formation of oxides and their harder reduction. Comparing voltammograms recorded for Ag-Cu alloy in 0.5 moldm-3 NaOH and in 1 moldm-3 NaOH solutions, one can see that current waves appear at more positive potentials on the voltammograms obtained in the solution of lower concentration and with much higher current densities than those on the voltammograms obtained in the solution of higher concentration.

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Effect of Different Dopants in Films TEOS/MPTS Used to Protect the Carbon Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.805.167 ◽

2014 ◽

Vol 805 ◽

pp. 167-171 ◽

Cited By ~ 1

Author(s):

F.S. Silva ◽

P.H. Suegama ◽

W.P. Silva ◽

A.W. Rinaldi ◽

N.L.C. Domingues ◽

...

Keyword(s):

Carbon Steel ◽

Open Circuit Potential ◽

Hybrid Film ◽

Electrochemical Impedance ◽

Open Circuit ◽

The Other ◽

Nacl Solution ◽

Hybrid Films ◽

Impedance Measurements ◽

Current Densities

Schiff bases m-toluene N-Salicylideneaniline (m-TOL), (B) m-nitro-N- Salicylideneaniline (m-NTR) and (C) m-methoxy-N-salicylideneaniline (m-MTX) and cerium ions were studied added to 3.5 wt.% NaCl solution and added to the hybrid film based tetraethoxysilane (TEOS) e 3-methacryloxypropyltrimethoxysilane (MPTS). The polarization measurements showed lower current densities for the steel in NaCl with m-MTX, indicating that the m-MTX may be acting as an inhibitor. The hybrid films were doped with the m-MTX, Ce (III) or Ce (IV). Electrochemical measurements of open circuit potential (EOC), polarization curves and electrochemical impedance spectroscopy (EIS), were used to evaluate the corrosion behavior of the hybrid films. According Electrochemical Impedance measurements, all hybrid films, provided protection to the carbon steel. The films doped with Ce (IV), provided greater protection than the other, which indicates that this is the most suitable dopant for use in films.

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Effect of Bi Addition on the Electrochemical Behavior of Zinc Electrodes in Concentrated Alkaline Solutions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.805-806.1240 ◽

2013 ◽

Vol 805-806 ◽

pp. 1240-1249

Author(s):

Hong Xia Liang ◽

Fu Rong Li ◽

Zhi Lin Wang

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Linear Polarization ◽

Electrochemical Behavior ◽

Open Circuit Potential ◽

Open Circuit ◽

Exchange Current ◽

Zinc Electrode ◽

Current Densities ◽

Scanning Electron

The electrochemical behavior of zinc electrode with bismuth addition in 35%KOH solutions has been investigated systematically by electrochemical methods including linear polarization, potentiostatic polarization, potential-time measurements at a constant current density, combining the observations of scanning electron microscopy (SEM). Linear polarization results showed that the open circuit potential shifted positively with increasing bismuth content, which is explained based on the gassing data and change in the exchange current of the zinc electrode. Addition of bismuth increased the exchange current of zinc reaction and caused an increase in the measured open circuit potential. Galvanostatic results showed that the addition of bismuth shortened the passivation time. Scanning electron microscopy images showed that the addition of bismuth aggravated the corrosion of zinc electrode which may be responsible for the increased tendency to passivation at high current densities. It has been found that at low current densities the reaction kinetics may be increased by addition of Bi, which is general agreement with the discharging test of actual alkaline batteries.

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Comparison of Electrochemical Behavior of Cu-10Ni-10Zn Alloy and Cu in Aqueous Solutions

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2014-0627 ◽

2015 ◽

Vol 229 (3) ◽

Cited By ~ 1

Author(s):

Waheed A. Badawy ◽

Mohamed M. El-Rabiei ◽

Hashem M. Nady ◽

Mohammed A. Samy

Keyword(s):

Electrochemical Behavior ◽

Electrochemical Impedance ◽

Electrochemical Techniques ◽

Pure Copper ◽

Open Circuit ◽

Chloride Ions ◽

Alloy Surface ◽

Metallic Surface ◽

Copper Dissolution ◽

Basic Solutions

AbstractThe electrochemical behavior of Cu-10Ni-10Zn alloy and Cu was investigated in acidic, neutral and basic solutions. The effect of chloride ions in neutral solutions was also studied. Conventional electrochemical techniques and electrochemical impedance spectroscopy were used. The corrosion rate of these materials in acidic solutions is relatively high compared to that in neutral or basic solutions. The open-circuit potential of the alloy is nearly the same as that of pure copper in the different media, indicating that the processes which occur on the alloy surface are mainly governed by copper dissolution. In chloride solutions the rate of Cu corrosion is remarkably high. In the alloy, the copper dissolution was suppressed by the presence of nickel and zinc, due to the formation of complex oxide layers. The impedance data were fitted to equivalent circuit models that explain the different electrochemical processes occurring at the electrode/electrolyte interface. SEM and EDAX have shown that the alloy surface is enriched with Ni. In neutral solutions the chloride ions are penetrating the metallic surface.

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Electrochemical behavior of stainless steel alloys used for medical and dental applications as a function of exposure to 0.9% NaCl and sterilization

Research Society and Development ◽

10.33448/rsd-v10i5.13544 ◽

2021 ◽

Vol 10 (5) ◽

pp. e32810513544

Author(s):

Cecília Alves de Sousa ◽

Carolina Ferrairo Danieletto-Zanna ◽

Thamara Beline ◽

Gustavo Zanna Ferreira ◽

Leonardo Perez Faverani ◽

...

Keyword(s):

Surface Roughness ◽

Stainless Steel ◽

Electrochemical Behavior ◽

Surface Characterization ◽

Electrochemical Impedance ◽

Open Circuit ◽

Surgical Instruments ◽

Nacl Solution ◽

Steel Alloys ◽

Significance Level

This study evaluated the effect of disinfection procedures and exposure to 0.9% NaCl solution cycles during sterilization, on the electrochemical, physical and chemical properties of different stainless steel alloys used in the biomedical field. Discs of F899 XM16, F899 303, and F899 420B alloys were cleaned with enzymatic detergent followed by 20 cycles of autoclave sterilization. Electrochemical tests were performed including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization tests in 0.9% NaCl (n=5). Surface characterization was performed using scanning electron microscopy (SEM), energy dispersive spectroscopy, and surface roughness and microhardness both before and after the electrochemical test. Quantitative data were analyzed with a significance level of 5%. The corrosion current density and corrosion potential of the alloys did not present statistical differences. The capacitance values of the three oxide layers, polarization resistance, and impedance of Warburg were similar among the alloys. Considering the topography, surface roughness increased for all alloys in the post-corrosion period. The stainless steel alloys analyzed were negatively affected at the electrochemical behavior, corrosion kinetics, and surface characterization after the 0.9% NaCl solution and the autoclave sterilization cycles, confirming the need for regular exchanges of surgical instruments and drills used in medical and dental implantology.

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An Electrochemical Study to Evaluate the Effect of Calcium Nitrite Inhibitor to Mitigate the Corrosion of Reinforcement in Sodium Chloride Contaminated Ca(OH)2Solution

Advances in Materials Science and Engineering ◽

10.1155/2017/6265184 ◽

2017 ◽

Vol 2017 ◽

pp. 1-14 ◽

Cited By ~ 3

Author(s):

Hwa-Sung Ryu ◽

Jitendra Kumar Singh ◽

Han-Seung Lee ◽

Won-Jun Park

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Sodium Chloride ◽

Anodic Polarization ◽

Open Circuit Potential ◽

Electrochemical Impedance ◽

Open Circuit ◽

Nacl Solution ◽

Steel Rebar ◽

Calcium Nitrite ◽

Corrosion Of Steel

The effect of calcium nitrite (Ca(NO2)2) was assessed by electrochemical means such as open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic studies in saturated Ca(OH)2solution contaminated with 0.99 and 7.91 g/L NaCl. The preliminary results of OCP showed that the potential is shifted towards positive (noble) side as content of inhibitor increased. The EIS results indicate that Ca(NO2)2works effectively in reduction and initiation of corrosion of steel rebar in NaCl contaminated Ca(OH)2solution. Potentiodynamic studies revealed the pitting tendency of steel rebar exposed in 0.99 g/L NaCl at [Cl−/NO2-] = 1.2 attributed to low conductivity of passive film which causes interference for Cl−ions attack during anodic polarization. The 85.75% efficiency is found in 0.99 g/L at [Cl−/NO2-] = 1.2. The Ca(NO2)2inhibitor transformed the unstable iron oxides/hydroxides into stable and protective oxides/hydroxides due to its strong oxidizing nature. Therefore, this inhibitor is sufficiently and significantly reducing the corrosion of steel rebar at even its low concentration with 0.99 and 7.91 g/L NaCl solution.

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Electrochemical Activity and Damage of Single Carbon Fiber

Materials ◽

10.3390/ma14071758 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1758

Author(s):

Xiaodong Chen ◽

Chi Zhang ◽

Guang-Ling Song ◽

Dajiang Zheng ◽

Yang Guo ◽

...

Keyword(s):

Carbon Fiber ◽

Anodic Polarization ◽

Cathodic Polarization ◽

Fiber Surface ◽

Electrochemical Activity ◽

Potential Range ◽

Polarization Current ◽

Nacl Solution ◽

Covalent Bonds ◽

Current Densities

The electrochemical activity of a carbon fiber was characterized at different potentials in 3.5 wt.% NaCl solution, and the fiber cylindrical surface changed by polarization at different potentials was revealed by SEM, AFM, optical microscopy, FTIR spectroscopy, Raman spectroscopy, and XRD. The results showed that the carbon fiber exhibited different electrochemical activities at some polarization potentials; within a 3V potential range the anodic and cathodic polarization current densities stepped up by more than 5 orders of magnitude, and the carbon fiber (CF) surface dramatically changed with time. Strong anodic polarization appeared to facilitate the breakdown of C-C covalent bonds in the carbon fiber and enhance the amorphization of the fiber surface.

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On the Corrosion Mechanisms of Al-Cu-Fe Quasicrystals

MRS Proceedings ◽

10.1557/proc-643-k2.3 ◽

2000 ◽

Vol 643 ◽

Author(s):

A. Rüdiger ◽

U. Köster

Keyword(s):

Anodic Polarization ◽

Open Circuit Potential ◽

Selective Dissolution ◽

Open Circuit ◽

Al Content ◽

Small Influence ◽

Current Densities ◽

Corrosion Mechanisms ◽

Nanocrystalline Layer ◽

Quasicrystalline Structure

AbstractThe mechanisms of dissolution and passivation of bulk polycrystalline icosahedral Al63Cu25Fe12 during electrolytic corrosion in 0.1 N NaOH and 1 N H2SO4 were studied in detail. In 1 N H2SO4 selective dissolution of Al and Fe occurs at the open circuit potential, which leads to a porous layer of recrystallized fcc Cu; after anodic polarization dissolution of the alloy is followed by redeposition of Cu and formation of Cu2O. In 0.1 N NaOH selective dissolution of Al was observed and a nanocrystalline layer consisting of Cu2O and FeOOH forms at the open circuit potential as well as during anodic polarization up to -150 mVSHE. At higher potentials Cu-ions dissolve into the electrolyte, which allows building up an Al-hydroxide layer. Presumably due to the loss of Al during polarization phase transforma-tions of the quasicrystals (e.g. continuous transformation or precipitation) were observed by transmission electron microscopy.In order to clarify the influence of the quasicrystalline structure on the corrosion, open circuit potentials and current densities of the quasicrystalline and three ternary crystalline phases with different Al-content, but approximately constant ratio Cu:Fe of 2:1 were compared. Lower current densities, but a less noble open circuit potential for the quasicrystals than expected from the trend over the Al-content indicate a small influence of the quasicrystalline structure.

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