Electrode Behaviour of a Suspension of Insoluble Material

Dausheva, M R; Songina, O.A.

doi:10.1070/rc1973v042n02abeh002570

Cited by 15 publications

(2 citation statements)

References 15 publications

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“…7 Results of DD analysis of an atmospheric aerosol: kinetic curves for dissolution of all elements constituting the aerosol (a); time dependences of the Ca, Sr, Ba, Mg, and Si dissolution degree (b). Dotted lines indicate the dissolution periods of phases with composition shown in Table 2 Fig [17]. Micka was the first to suppose that polarography of suspensions could be used for phase analysis of inorganic solids and compete with X-ray diffraction method.…”

Section: Polarography Of Insoluble Suspensionsmentioning

confidence: 98%

Determination of chemical composition of solid inorganic substances and materials using the principles of stoichiography and voltammetry

Malakhov

2012

J Solid State Electrochem

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The state of the art in determination of the phase composition of complex inorganic solids by chemical and electrochemical methods is discussed. The theoretical and practical essentials of stoichiography and the new stoichiographic method of differential dissolution (DD) are reported. The unique feature of this method is that reference samples of the analyzed solid phases are not necessary. The development of this stoichiographic method was strongly affected by voltammetry. The application of the DD method for determining the chemical composition of various substances and materials is presented. The complementary use of voltammetry and DD for the detection, identification, and quantitative determination of inhomogeneity of the chemical composition of hightemperature superconductors was shown to be efficient.

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Section: Polarography Of Insoluble Suspensionsmentioning

confidence: 98%

Determination of chemical composition of solid inorganic substances and materials using the principles of stoichiography and voltammetry

Malakhov

2012

J Solid State Electrochem

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“…This constitutes what is commonly named "partially blocked electrode" (24,25). It is obvious that adhesion of the particles between them or to the electrode, cannot occur, because of their indeformabilJties, through capillary forces (26) but through electrical and roughness forces.…”

Section: Partial Blockage Of the Interface With Respect To The Diffus...mentioning

confidence: 99%

Mass Transfer in Laminar Flow at a Rotating Disk Electrode in Suspensions of Inert Particles: II . Theoretical Evaluation of Experimental Results

Caprani

Ficquelmont‐Loïzos

Tamisier

et al. 1988

J. Electrochem. Soc.

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In a previous publication, we studied mass transfer at a rotating disk electrode in "inert" particle suspensions. We now account for the variations of the limiting diffusion current with numerous parameters by different phenomena. These involved either the topography of the interface through adhesion of the particles to the electrode or the mass exchanges in the diffusion layer through changes in the velocity field and/or diffusion coefficient. Each phenomenon, considered separately, gives rise to one or more linear segments for the variations of current with the rotation speed ft, in logarithmic coordinates. Considering all the invoked phenomena, we would expect more segments than the four observed in experimental log I vs. log gt plots. Analyzing the consequences of each phenomenon in the whole f~ range allows one to disregard some of them for certain ft values and to account for most of the experimental results. At low ft values, two predominant phenomena, with antagonistic effects, explain the deviations from the one-phase media behavior: the reduction of the exchange area and the increase of the apparent diffusion coefficient through changes in the size of aggregates along the streamlines. Moreover. for small-size particles or for particle concentrations sufficiently high, deviations from newtonian behavior are also observed. At intermediate and high ~ values, the predominant phenomenon is the variation of the diffusion coefficient with the shear rate. Depending on the ratio of the diffusion layer thickness over the particle size (g/a), two different laws can describe this variation.In the first paper of this series (1), we determined, using an electrochemical method, the influence of several parameters on mass transfer in two-phase media. These parameters are inherent in the particle, the medium, and the rotating disk electrode (RDE). The fact that the influence of each of them is closely dependent on the influence of the others suggests that various phenomena must take place at the interface, with shear rate dependent relative weights.We present here a general model in order to take into account most of our experimental results and to interpret the "particle-wall-flow" interactions which control the mass transfer to the wall.The particles are known to induce discrepancies on mass transfer with respect to the supernatant. Three different approaches have been used in the literature to account for these discrepancies: a hydrodynamic approach, a diffusional approach, and a third approach in which blocking of the exchange area is invoked. The two first approaches disregard the role of the electrode surface, and lead to an increase of mass transfer. The third approach only takes into account the phenomena at the interface and leads to a decrease of mass transfer. This last approach ignores the particle-induced perturbations of the volume-related phenomena.The first and most microscopic approach was employed in the case of the rotating disk electrode (2, 3). It consists in solving with important approximations th...

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Development of analytical procedures based on abrasive stripping coulometry and voltammetry for solid state phase microanalysis of natural and synthetic tin‐, arsenic‐, and antimony‐bearing sulfosalts and sulfides of thallium, tin, lead, and silver

et al. 1995

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Analytical procedures are described for the solid state phase microanalysis of synthetic and natural tin-, arsenic-, and antimony-bearing sulfosalts and sulfides of thallium, tin, lead, and silver. In these procedures, abrasive stripping voltammetry and coulometry of the solid phases are applied. Trace amounts of the sample compounds were transferred onto the surface of a graphite electrode and the electrochemical reduction or oxidation was followed by voltammetric techniques. The most valuable technique for distinguishing different mineral phases is to record the anodic dissolution voltammograms after a preliminary electrolytic reduction of the sulfides or sulfosalts to the elementary metals which are still confined to the electrode surface. For various compounds an approach was developed in which the ratio of charges consumed during reduction and oxidation of the solid phases is used for unambiguous identification. Coulometric measurements are also used for the determination of the quantitative composition of the solid phases.

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Electrode Behaviour of a Suspension of Insoluble Material

Cited by 15 publications

References 15 publications

Determination of chemical composition of solid inorganic substances and materials using the principles of stoichiography and voltammetry

Determination of chemical composition of solid inorganic substances and materials using the principles of stoichiography and voltammetry

Mass Transfer in Laminar Flow at a Rotating Disk Electrode in Suspensions of Inert Particles: II . Theoretical Evaluation of Experimental Results

Development of analytical procedures based on abrasive stripping coulometry and voltammetry for solid state phase microanalysis of natural and synthetic tin‐, arsenic‐, and antimony‐bearing sulfosalts and sulfides of thallium, tin, lead, and silver

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