Electrochemical Behavior of Silver in Sodium Sulphate Solution during Anodic Polarization Revisited

2013 ◽  
Vol 29 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Bayeshov Abduali ◽  
Tuleshova Elmira ◽  
Tukibayeva Ainur
Keyword(s):  
Electrochemical Behavior ◽  
Anodic Polarization ◽  
Sodium Sulphate ◽  
Sulphate Solution

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

2017 ◽  
Vol 53 (3) ◽  
pp. 349-356 ◽  
Author(s):  
V. Grekulovic ◽  
M. Rajcic-Vujasinovic ◽  
A. Mitovski
Keyword(s):  
Electrochemical Behavior ◽  
Electrode Surface ◽  
Anodic Polarization ◽  
Pure Copper ◽  
Inhibitory Effect ◽  
Open Circuit ◽  
Alkaline Media ◽  
Nacl Solution ◽  
Pure Silver ◽  
Current Densities

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.

scholarly journals Electrochemical Behavior of Conventional and Rheo-High-Pressure Die Cast Low Silicon Aluminum Alloys in NaCl Solutions

CORROSION ◽  
10.5006/3254 ◽  
2019 ◽  
Vol 75 (11) ◽  
pp. 1339-1353
Author(s):  
Maryam Eslami ◽  
Flavio Deflorian ◽  
Caterina Zanella
Keyword(s):  
High Pressure ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Behavior ◽  
Anodic Polarization ◽  
Electrochemical Impedance ◽  
Casting Process ◽  
Corrosion Mechanism ◽  
Die Cast ◽  
Polarization Test

The electrochemical behavior of a low silicon aluminum alloy cast by the conventional and rheo-high-pressure die cast processes is evaluated using polarization test and electrochemical impedance spectroscopy in 0.01 M, 0.05 M, 0.1 M, and 0.6 M sodium chloride solutions. Compared to the conventional high-pressure die cast process, rheocasting introduces some alterations in the microstructure including the presence of aluminum grains with different sizes, formed at different solidification stages. According to the results of the anodic polarization test, conventional cast and rheocast samples show similar breakdown potentials. However, the rheocast samples present enhanced oxygen reduction kinetics compared to the conventional cast sample. Based on scanning electron microscopy examinations, localized microgalvanic corrosion is the main corrosion mechanism for both alloys and it initiates at the interface of aluminum with iron-rich intermetallic particles which are located inside the eutectic regions. The corrosion further develops into the eutectic area. Although the rate of the cathodic reaction can be influenced by the semisolid microstructure, according to the results of anodic polarization and electrochemical impedance spectroscopy tests, the corrosion behavior is not meaningfully affected by the casting process.

ELECTROCHEMICAL BEHAVIOR OF ELECTRODEPOSITED NANOCRYSTALLINE COBALT-IRON ALLOY COATING IN DIFFERENT PH

2015 ◽  
Vol 76 (10) ◽  
Author(s):  
Nik Rozlin Nik Mohd Masdek ◽  
Akram Alfantazi
Keyword(s):  
Dissolution Rate ◽  
Electrochemical Behavior ◽  
Iron Alloy ◽  
Alloy Coating ◽  
Sodium Sulphate ◽  
Basic Medium ◽  
Anodic Reaction ◽  
Cobalt Iron ◽  
Sulphide Ions ◽  
Basic Solutions

The electrochemical behavior of a cobalt-iron (CoFe) alloy electrode in 0.1 M Na2SO4 (sodium sulphate) aqueous solution of different pH was investigated. The presence of a different concentration of dissolved sulphide ions with different pH on the corrosion of electrodeposited cobalt-iron was investigated using the EQCM technique. The corrosion rates of the alloys in acidic solutions are pronouncedly high, compared to those measured in neutral or basic solutions. The presence of sulphide ions accelerates markedly the anodic reaction for all deposits in the basic medium. The dissolution rate was twice two times faster when S2− was added. By employing the EQCM, it was observed that the mass decrease or dissolution rate was significant with an increase in pH concentration. 

Corrosion of Galvanized and Galvannealed Steel in Solutions of pH 9.0 to 14.0

CORROSION ◽  
1985 ◽  
Vol 41 (11) ◽  
pp. 618-624 ◽  
Author(s):  
G. Sergi ◽  
N. R. Short ◽  
C. L. Page
Keyword(s):  
Electrochemical Behavior ◽  
Anodic Polarization ◽  
Marked Effect ◽  
Alloy Layer ◽  
Zinc Alloy ◽  
Solution Ph ◽  
X Ray ◽  
Potentiodynamic Anodic Polarization ◽  
Zinc Coatings ◽  
Galvannealed Steel

Abstract Well-characterized zinc coatings on steel have been prepared so that either the eta or zeta phase was present as the outermost layer. Their electrochemical behavior was studied in a range of solutions by galvanostatic anodic polarization and potentiodynamic anodic polarization scans. The corrosion products were identified using scanning electron microscopy (SEM) and x-ray analysis. Results show that the solution pH has the most marked effect on electrochemical behavior and the nature of the corrosion product formed. At a given solution pH, the behavior and products formed are modified according to the concentration of chloride in the solution and the type of iron-zinc alloy layer investigated. The results are discussed in relation to the practical use of galvanized reinforcement in concrete.

Thaumasite formation in limestone filler cements exposed to sodium sulphate solution at 20 °C

2005 ◽  
Vol 27 (1) ◽  
pp. 77-84 ◽  
Author(s):  
E.F. Irassar ◽  
V.L. Bonavetti ◽  
M.A. Trezza ◽  
M.A. González
Keyword(s):  
Sodium Sulphate ◽  
Sulphate Solution ◽  
Limestone Filler

scholarly journals Assessment of Bowel Preparation Using Low-Volume Sulphate-Based Preparations in Comparison with Macrogols: A Multicenter, Randomized, Comparative Clinical Study of the 3rd Phase

2019 ◽  
Vol 29 (1) ◽  
pp. 68-83
Author(s):  
Evgeny D. Fedorov ◽  
Viktor V. Veselov ◽  
Sergey V. Kashin ◽  
Ekaterina V. Tikhomirova ◽  
Alexey V. Veselov ◽  
...  
Keyword(s):  
Bowel Preparation ◽  
Sodium Sulphate ◽  
Sulphate Solution ◽  
P Value ◽  
Common Symptom ◽  
Polyp Detection ◽  
Diagnostic Colonoscopy ◽  
Intention To Treat ◽  
Comparative Clinical Study ◽  
Low Volume

Oral sulphate solution(OSS: sodium sulphate, potassium sulphate and magnesium sulphate) is a low-volume osmotic agent for cleansing the intestines.Aim:in a multicentre, prospective, randomized, 3rd phase study with two parallel groups, the effectiveness, safety and tolerability of OSS was evaluated in comparison with Macrogol 4000 with electrolytes (a reference preparation for bowel cleansing in Russia) in adult patients who were scheduled for routine diagnostic colonoscopy.Methods.This study was conducted in three Russian research centres during the March–December, 2015 period. Men and women over the age of 18 scheduled to undergo routine diagnostic colonoscopy were randomly assigned either to the OSS group or to the Macrogol group with a fractional use mode before the colonoscopy. The colonoscopy researchers were not aware of which preparation had been taken by the patients. Anonymized video records were centrally analysed by three experts. The primary end point was the proportion of patients with a successful bowel preparation for colonoscopy ≥6 points, as determined by theBoston Bowel Preparation Scale of quality assessment(BBPS scale).Results.296 patients were randomized in the study (147 patients were treated with OSS, 149 patients received Macrogol); 294 participants were included in theIntention to Treat population(ITT-population), and 274 participants were included in thepopulation of patients who completed the study according to the protocol(Per-Protocol; PP-population) (139 patients received OSS, 135 patients received Macrogol). The proportion of patients with a successful bowel preparation (BBPS ≥6 scores) was high in both groups (OSS [PP-population]: 97.2 % (95 % confidence interval [CI] 89.5–99.3), Macrogol [PP-population]: 97.7 % (95 % CI: 90.7–99.4)). The corrected difference between the groups was -0.5 % (95 % CI: -4.2–3.3), thereby demonstrating “no less effective” of OSS as compared to Macrogol. Compliance with the drug use regime was higher in the OSS group than in the Macrogol group (95.7 % versus 82.3 %, respectively, p-value = 0.0011, ITT-population).The most common symptom reported in patients was nausea (27.9 % in the OSS group and 12.9 % in the Macrogol group). The proportion of patients who developed nausea was significantly higher in the OSS group than in the Macrogol group (25.2 % compared with 10.2 % when taking the first dose of the preparation (p = 0.0008) and 19.7 % compared with 6.8 % when taking the second dose of the preparation (p = 0.0016)). Differences in other symptoms (bloating, abdominal pain or abdominal discomfort) between the groups were not significant, with the severity of symptoms being generally mild. The safety profile of the investigated preparations in patients withinflammatory bowel disease(IBD) in remission did not differ from that in the general patient population.The differences in terms of secondary endpoints were not identified, including BBPS assessment for different sections of the colon, the level of polyp detection, the duration and completeness of colonoscopy, and the investigator’s satisfaction with the procedure. The analysis by subgroups also did not reveal any significant differences.Conclusion.In this study, the “not less effectiveness” of the sulphate solution was demonstrated as compared to Macrogol in a fractional use mode. Both preparations were well tolerated. Despite the higher incidence of nausea in the OSS group, the patients showed significantly higher compliance with the OSS mode as compared to that of Macrogol.This study is registered with the ClinicalTrials.gov Registry of Clinical Trials, No. NCT02321462.

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