The electrochemical formation of mercuric oxide in alkaline solution

1978 ◽  
Vol 56 (3) ◽  
pp. 336-342 ◽  
Author(s):  
Remigio Germano Barradas ◽  
Stephen Fletcher ◽  
John Douglas Porter
Keyword(s):  
Computer Simulations ◽  
Growth Mechanism ◽  
Model Test ◽  
Alkaline Solution ◽  
Reference Electrode ◽  
Electrode System ◽  
Alkaline Solutions ◽  
Mercuric Oxide ◽  
Derived Data ◽  
Theoretical Developments

The electrochemical formation of mercuric oxide on mercury in alkaline solutions is described. The reaction was investigated because of its importance as a reference electrode system, and also because it provides a model test of recent theoretical developments. Various derived data are compared to computer simulations of the growth mechanism.

Evaluation of a molybdenum sulfide reference electrode in hot alkaline solutions

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 35-41
Author(s):  
OUTI A. HYÖKYVIRTA ◽  
TOM E. GUSTAFSSON
Keyword(s):  
Molybdenum Disulfide ◽  
Surface Film ◽  
Reference Electrode ◽  
Exposure Period ◽  
Molybdenum Sulfide ◽  
Alkaline Solutions ◽  
Internal Reference ◽  
Cell Potential ◽  
Pulp Digester ◽  
Alkaline Sulfide

This investigation evaluated the applicability of a molybdenum sulfide reference electrode (MSRE) as an internal reference electrode for use in alkaline sulfide solutions over a range of pulp digester liquors at 170°C. The electrode remained stable during the exposure period of two weeks. The experimentally determined half cell potential of the MSRE is E = -0.91 VSHE. The surface of the MSRE was examined by scanning electron microscope (SEM) and electron spectroscopy for chemical analysis (ESCA) to verify the chemical composition of the thin surface film. Based on ESCA studies, the surface film contained molybdenum disulfide and sodium disulfide. During storage of the specimens, sulfide was partly oxidized to sodium sulfite in air. Next to the metallic molybdenum, a mixed molybdenum disulfide and molybdenum hydroxide layer was detected.

Chemical deposition of hard composite coatings Ni–Cu–P–Cr2O3

2020 ◽  
pp. 179-181
Author(s):  
A.A. Abrashov A.A. ◽  
E.G. Vinokurov ◽  
M.A. Egupova ◽  
V.D. Skopintsev
Keyword(s):  
Chromium Oxide ◽  
Alkaline Solution ◽  
Composite Coatings ◽  
Chemical Deposition ◽  
Alkaline Solutions ◽  
Functional Surface ◽  
Heat Treated ◽  
Weakly Acid Solution ◽  
Coating Composition ◽  
Weakly Acidic Solution

The technological (deposition rate, coating composition) and functional (surface roughness, microhardness) characteristics of chemical composite coatings Ni—Cu—P—Cr2O3 obtained from weakly acidic and slightly alkaline solutions are compared. It is shown that coatings deposited from slightly alkaline solution contain slightly less phosphorus and chromium oxide than coatings deposited from weakly acid solution (2...3 % wt. phosphorus and up to 3.4 % wt. chromium oxide), formed at higher rate (24...25 microns per 1 hour of deposition at temperature of 80 °C), are characte rized by lower roughness and increased microhardness. The Vickers microhardness at 0.05 N load of composite coatings obtained from slightly alkaline solution and heat-treated at 400 °C for 1 hour is 13.5...15.2 GPa, which is higher than values for coatings deposited made of weakly acidic solution. The maximum microhardness of coatings is achieved at concentration 20 g/l of Cr2O3 particles. The technology of chemical deposition of Ni—Cu—P—Cr2O3 coatings formed in slightly alkaline solution is promising for obtaining of materials with increased hardness and wear resistance.

scholarly journals Screen-printed Paper-based Three-electrode System with Long-term Stable and Instantaneously Usable Reference Electrode

2018 ◽  
Vol 47 (12) ◽  
pp. 1502-1504 ◽  
Author(s):  
Isao Shitanda ◽  
Masato Komoda ◽  
Yoshinao Hoshi ◽  
Masayuki Itagaki
Keyword(s):  
Reference Electrode ◽  
Electrode System ◽  
Screen Printed

scholarly journals Two Electrode ECG And EOG System For Monitoring Applications

2019 ◽  
Vol 8 (11) ◽  
pp. 262-265
Keyword(s):  
Reference Electrode ◽  
Cost Effective ◽  
Electrode System ◽  
Ecg Signal ◽  
Biomedical Signal ◽  
Ecg Signals ◽  
Arm Position ◽  
The Stability ◽  
Electrocardiogram Ecg ◽  
Total Gain

Heart and Eye are two vital organs in the human system. By knowing the Electrocardiogram (ECG) and Electro-oculogram (EOG), one will be able to tell the stability of the heart and eye respectively. In this project, we have developed a circuit to pick the ECG and EOG signal using two wet electrodes. Here no reference electrode is used. EOG and ECG signals have been acquired from ten healthy subjects. The ECG signal is obtained from two positions, namely wrist and arm position respectively. The picked-up biomedical signal is recorded and heart rate information is extracted from ECG signal using the biomedical workbench. The result found to be promising and acquired stable EOG and ECG signal from the subjects. The total gain required for the arm position is higher than the wrist position for the ECG signal. The total gain necessary for the EOG signal is higher than the ECG signal since the ECG signal is in the range of millivolts whereas EOG signal in the range of microvolts. This two-electrode system is stable, cost-effective and portable while still maintaining high common-mode rejection ratio (CMRR).

scholarly journals A novel experimental approach for studying spontaneous imbibition processes with alkaline solutions

2019 ◽  
Vol 89 ◽  
pp. 04004
Author(s):  
T. Chevalier ◽  
J. Labaume ◽  
A. Delbos ◽  
T. Clemens ◽  
V. M. Waeger ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Alkaline Solution ◽  
Recovery Process ◽  
Oil Field ◽  
Spontaneous Imbibition ◽  
Alkaline Solutions ◽  
Vienna Basin ◽  
Natural Surfactants ◽  
Current Flows ◽  
Kinetics Of

Spontaneous imbibition processes can play an important role in oil production. It can be enhanced or influenced by wettability changes generated by properly designed chemicals or by the natural surfactants resulting from reactive crude oils in the presence of alkaline solutions. The reaction of basic salts with some components of oil can, indeed, lead to the formation of natural soaps that reduces the interfacial tension between oil and brine. The latter scenario is studied herein on samples and oil from the St Ulrich oil field in the Vienna basin. To that end, spontaneous imbibition experiments were performed with two brines differing by the absence or presence of alkali. We first present a general novel technique to monitor saturation changes on small rock samples for the purpose of assessing the efficiency of a given recovery process. Samples of only 15 mm in diameter and 20 mm in length and set at irreducible saturation were fully immersed in the solution of interest, and the evolution of the samples’ saturation with time was monitored thanks to a dedicated NMR technique involving the quantification of the sole oil phase present within the sample. A fully-3D imbibition configuration was adopted, involving counter-current flows through all faces of the sample. The experimental method is fast for two reasons: (i) the kinetics of capillary imbibition process is proportional to the square of sample size, i.e. very rapid if accurate measurements can be acquired on tiny samples, (ii) the present 3D situation also involves faster kinetics than the 1D configuration often used. The NMR technique was crucial to achieve such conditions that cannot be satisfied with conventional volumetric methods. The kinetics of oil desaturation during spontaneous imbibition is interpreted with the help of an analytical 3D diffusion model. For the alkaline solution, the diffusion coefficient is reduced by a factor of only two compared to the non-alkaline brine, although the interfacial tension between the oil and the imbibing solution is reduced by a factor of 10. Hence, a wettability change to a more water wet state has to be assumed when the alkaline solution replaces the non-alkaline solution in the imbibition process. However, no significant impact on the final saturation was observed.

Effect of surfactants on capacitance properties of carbon electrodes

2011 ◽  
Vol 1333 ◽  
Author(s):  
Krzysztof Fic ◽  
Grzegorz Lota ◽  
Elzbieta Frackowiak
Keyword(s):  
Surface Tension ◽  
Alkaline Solution ◽  
Surfactant Concentration ◽  
Alkaline Solutions ◽  
Carbon Electrodes ◽  
Current Load ◽  
Target Concentration ◽  
Electrolyte Additives ◽  
Different Types ◽  
Triton X

ABSTRACTEffect of surfactants present in alkaline solutions on the capacitance of carbon electrodes has been studied. Different types of surfactants have been selected for this target. Concentration of these electrolyte additives was 0.005 mol L-1. Decreasing the surface tension in the electrode/electrolyte interface allows better penetration of electrolyte into the pores. Detailed analysis of capacitance versus current load, frequency dependence as well as self-discharge, cyclability and behaviour in wider voltage window proved a useful effect of Triton X-100 on capacitor operating in alkaline solution. Influence of surfactant concentration has also been investigated.

All-Solid-State Reference Electrode Based on Polymer Composites for Corrosion Monitoring of Steel in Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 2945-2948
Author(s):  
Li Juan Kong ◽  
Tong Zhang ◽  
Guang Pin Song
Keyword(s):  
Solid State ◽  
Civil Engineering ◽  
Reference Electrode ◽  
Steel Corrosion ◽  
Steel Structures ◽  
Electrode System ◽  
Corrosion Monitoring ◽  
Steel Bar ◽  
State Reference ◽  
Corrosion Of Steel

Corrosion of steel structures has been found to be a problem Corrosion can be managed but not eliminated, so detecting corrosion will remain an issue no matter how effective corrosion prevention programs become. Electrochemical reaction is the basically process of steel corrosion in civil engineering, so electrochemical method is the best way to monitor corrosion grade. Liquid state reference is often used in lab to study steel corrosion by triple electrode system, but it is very difficultly used in steel bar corrosion monitoring in civil engineering. Firstly, liquid reference’s life is, generally speaking, very short. The steel corrosion is a very slow process, corrosion monitoring should be tens of years, so the liquid reference’s life is not long enough for corrosion monitoring; Secondly, the reference electrode’s strength have to be very high. Obviously, liquid electrode reference can not meet the requirement. In this paper, a novel all solid state reference electrode (ASSRE) has been developed. There are three layers in the electrode. Four kinds of components have been included in first and second layer. Additional AgCl powder has been used to inhibit AgCl decrease which is on the surface of Ag wire by complexing effect. There is only one kind of component in third layer. There are four steps to prepare the reference electrode: electrolyze, pre-mixed components, modelling and sintering. Finally, the potential of ASSR has been measured by SCE.

The hydrolysis of maleimide in alkaline solution

1976 ◽  
Vol 54 (9) ◽  
pp. 1400-1404 ◽  
Author(s):  
Remigio Germano Barradas ◽  
Stephen Fletcher ◽  
John Douglas Porter
Keyword(s):  
Alkaline Solution ◽  
Reaction Scheme ◽  
Rate Equations ◽  
Bulk Concentration ◽  
Rate Of Reaction ◽  
Ph Range ◽  
Derived Data ◽  
Hydrolysis Of

The hydrolysis of maleimide has been investigated in the pH range 8.5–14. Polarographic limiting currents were well-defined, so that the bulk concentration of reactant during reduction could be clearly followed as a function of time. Logarithmic analysis of derived data indicated an arrest in the rate of reaction at circa pH 12, and a reaction scheme is proposed to explain this. In this scheme, the neutral maleimide molecule exists in equilibrium with its anion, and both of these species may undergo hydrolysis at the appropriate pH. From derived rate equations, the pKa of maleimide was found to be 10.0, whilst estimates of the rates of hydrolysis were also calculated.

scholarly journals Front Cover: Simultaneous Multiplex Potentiostatic Electroanalysis with Liquid-Junction-Removed Reference Electrode System using a Closed Bipolar Electrode (ChemElectroChem 16/2018)

2018 ◽  
Vol 5 (16) ◽  
pp. 2157-2157
Author(s):  
Kumi Y. Inoue ◽  
Miho Ikegawa ◽  
Takahiro Ito-Sasaki ◽  
Shinichiro Takano ◽  
Hitoshi Shiku ◽  
...  
Keyword(s):  
Reference Electrode ◽  
Electrode System ◽  
Bipolar Electrode ◽  
Liquid Junction ◽  
Front Cover
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