The Static Electrode Potential Behavior Of Aluminum and the Anodic Behavior of the Pure Metal And Its Alloys in Chloride Media

CORROSION ◽  
1957 ◽  
Vol 13 (12) ◽  
pp. 27-32 ◽  
Author(s):  
E. M. KHAIRY ◽  
M. KAMAL HUSSEIN
Keyword(s):  
Double Layer ◽  
Electrode Surface ◽  
Electrode Potential ◽  
Pure Metal ◽  
Chloride Ions ◽  
Surface Oxide ◽  
Anodic Behavior ◽  
Buffer Solutions ◽  
Corrosive Effect

Abstract The electrode potential behavior of aluminum investigated in buffer solutions of pH 4-8 containing varying concentrations of chloride ions, shows that the electrode potential does not respond to variations of pH. It changes linearly with pCl yielding a more or less constant Eo′ value of —0.54 volt. The corroding effect of the chloride ions supposedly is restricted to the adsorption of these ions on the surface and the electrode behaves as one of the second type. The oscillograms obtained both with the pure metal and with its alloys indicate that the surface oxide resists the corrosive effect up to a 0.1-N [CI–]. At higher concentrations, the electrode surface is appreciably activated acquiring relatively high double layer capacities, prominent passivity being achieved only on passing appropriate amounts of electricity. 6.4.2

An Electrochemical Study Of Aluminum And Aluminum Alloys

CORROSION ◽  
1959 ◽  
Vol 15 (2) ◽  
pp. 27-31 ◽  
Author(s):  
E. M. KHAIRY ◽  
M. KAMAL HUSSEIN
Keyword(s):  
Aluminum Alloys ◽  
Metal Ions ◽  
Pure Metal ◽  
Chloride Ions ◽  
Anodic Behavior ◽  
Buffer Solutions ◽  
Electrode Potentials ◽  
Oscillographic Method ◽  
Ph Range ◽  
Aluminum Base

Abstract Studies of the static electrode potentials of the R, Duralumin, M 22, DK and S 2 aluminum base alloys show that these alloys have the same behavior as pure metal in buffer solutions initially free from metal ions within the pH range 1 to 8. The repetitive oscillographic method was used to examine the corrosive action of chloride ions on the anodic behavior of the alloys studied. Oscillograms are presented to show the potentials of the alloys in various pH ranges. Composition of the buffer solutions at various pH levels are given in tables. 6.4.2

Le comportement électrochimique du magnésium en milieux légèrement alcalins

1980 ◽  
Vol 58 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Robert-Louis Brossard ◽  
Dominique-Louis Piron
Keyword(s):  
Corrosion Product ◽  
Hydrogen Evolution Reaction ◽  
Electrode Potential ◽  
Oxidation Mechanism ◽  
Chloride Ions ◽  
Anodic Behavior ◽  
High Concentration ◽  
Oxidation Layer ◽  
Kinetics Of ◽  
Simulated Seawater

This study of the anodic behavior of magnesium in simulated seawater has shown that the corrosion product formed at the surface of the electrode depends mainly on the nature of ions dissolved in the electrolyte. Analyses of the corrosion product, formed in the presence of a high concentration of chloride ions, are compatible with the formation of a compound having approximately the formula 5Mg(OH)2•MgCl2. However, this complex is gradually transformed over a period of several hours into Mg(OH)2.A model of the oxidation mechanism is presented in which the characteristics of the anodic behavior of magnesium are related to the structure of the oxidation layer. For example, the activation of the surface of the anode, the kinetics of the hydrogen evolution reaction, and the large difference between values of corrected and uncorrected electrode potential can all be explained by this model. It is the resistance of the film to the flow of current which controls the kinetics of anodic dissolution of magnesium.

scholarly journals Effect of Electrode Potential on Ag Electrodeposition on a Reconstructed Au(111) Electrode Surface

Hyomen Kagaku ◽  
2008 ◽  
Vol 29 (10) ◽  
pp. 621-628 ◽  
Author(s):  
Satoru TAKAKUSAGI ◽  
Ken KITAMURA ◽  
Kohei UOSAKI
Keyword(s):  
Electrode Surface ◽  
Electrode Potential

Einfluss der elektrochemischen Doppelschicht auf die Sorption und den Transport von Chlorionen im Zementstein / Influence of the electrochemical double layer on sorption and transport of chlorides in hardened cement paste

2000 ◽  
Vol 6 (4) ◽  
pp. 415-428
Author(s):  
O. Wowra ◽  
M.J. Setzer
Keyword(s):  
Double Layer ◽  
Cement Paste ◽  
Building Materials ◽  
Pore Solution ◽  
Chloride Ions ◽  
Transport Processes ◽  
Cement Matrix ◽  
Hardened Cement ◽  
Hardened Cement Paste ◽  
Electrochemical Double Layer

Abstract Besides the formation of Friedel salt the transport and binding of chlorides in concrete is mainly defined by the electrochemical double layer at the interface between cement matrix and pore solution. Due to the alkaline pore solution the surface of hardened cement paste is negatively charged which may change to positive values by the potential regulating calcium ions. Inverting of the surface charge leads to an attraction of anions and therefore, to an adsorption of chloride ions in the diffuse part of the electrochemical double layer. Influence from outside like sulphates and carbon dioxide may lead to a decomposition of Friedel salt. Apart from these effect temperature, pH-value and certain environmental conditions affects the electrochemical double layer as well. The chloride equilibrium is mainly controlled by adsorbed ions in the electrochemical double layer. The model presented here is relevant for the assessment of ion transport processes in mineral building materials. Continuing investigations may lead to optimize transport models and a better evaluation of the critical chloride threshold value in reinforced concrete.

Electrochemical Behavior of the Lead Electrode in HCl and NaCl Aqueous Electrolytes

1975 ◽  
Vol 53 (3) ◽  
pp. 389-406 ◽  
Author(s):  
Remigio Germano Barradas ◽  
Keith Belinko ◽  
John Ambrose
Keyword(s):  
Electrochemical Behavior ◽  
Electrode Surface ◽  
Sea Water ◽  
Spectroscopic Studies ◽  
Chloride Ions ◽  
Limiting Factor ◽  
Rotating Disc ◽  
Chloride Solutions ◽  
Aqueous Chloride ◽  
Hcl Concentration

The electrochemical properties of lead electrodes in aqueous chloride solutions were experimentally investigated over a range of 0.1 to 6.0 M HCl with the aim of extending previous work carried out only at 1.0 M HCl concentration. Experimental results using the rotating disc electrode technique, cyclic voltammetry, galvanostatic and potentiostatic charging conditions were employed in conjunction with spectroscopic studies of the electrolyte and X-ray powder diffraction analyses of electrode surface products. Experiments were also carried out in simulated sea water (3% NaCl) at different pH and compared with results obtained using HCl at the same molar concentration. At all chloride concentrations the overall reaction led to the formation of PbCl2 on the electrode surface, with the exception that in NaCl solutions where pH ≥ 6.5, Pb(OH)Cl was found to be one of the products. For concentrations of less than 0.4 M HCl, our results indicated that the diffusion of chloride ions to the electrode surface was the limiting factor in the formation of a passivating PbCl2 layer. At concentrations of about 0.7 M HCl, the electrochemical behavior showed a pattern of results which were interpreted in terms of a "passivation–dissolution" competitive mechanism consistent with the solubility minimum of PbCl2 in aqueous chloride solutions.

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