K. A. Kazdobin

National Academy of Sciences of Ukraine | ISP · V. I. Vernadsky Institute of General and Inorganic Chemistry

The studies of electrochemical properties of electrolyte system - sodium bis[salicylato(2-)]-borate - γ-butyrolactone (NaBSB-GBL) in the temperature range 17÷60 °C have been presented. The influence of the temperature on the conductivity of Na bis[salicylato(2-)]-borate - γ-butyrolactone electrolytes has been quantified. Probable types of charge tr...

Paper is aimed on seek-up of new “green” energy sources. The changes in the mechanism and the selectivity of components binding from the enzyme mixture extracted from Black Horseradish adsorbed on the kaolin and aerosil are proved. The differences in the binding mechanisms of metal-containing sites of enzyme molecules based on the implementation of...

Our studies of quaternary ammonium bis(chelato)borate Me 4 NBSB in DMFA and DMAA showed that depending on the solvent obtained electrolytes may exhibit different properties. For the design of an electrolyte with desired properties the structural and chemical properties of salt and solvent and the possibility of chemical interaction leading to the f...

By the methods of cyclic voltammetry and electrochemical impedance spectroscopy, it is shown that the oxidation of electrodes made of an AB2 -type zirconium alloy in air reduces the activation period and increases the electrochemical capacity. The improvement of the charge-discharge characteristics of zirconium alloys after mechanical activation is...

The changes in the mechanism and the selectivity of binding of the components from the enzyme preparation from Raphanus sativus L. var. niger adsorbed on both the natural bentonite and bentonite modified by phosphate ions are proved by several physical and chemical methods. The influence of the amphoterity of the acid–base properties of the support...

The synthesis of lithium, sodium, and potassium bis(salicilato)borates (LiBSB, NaBSB, and KBSB) is carried out by a microwave method, whose application makes it possible to shorten the synthesis duration by 8–10 times and to obtain the product yield close to the quantitative one. The product purity and the nature of impurities are determined by the...

Concentrations of hydrogen peroxide in dynamic (flowing) electrolytes and suspension systems have been determined using the methods of potentiometric redox-titration and cyclic voltammetry. The quantitative determination of H2O2 up to concentration ≈ 10–6 M was shown to be possible by using microelectrodes polarized in the convective diffusion mode...

In a study of the interaction between an enzyme preparation of black horseradish and various inorganic substrates (kaolin, aerosil, bentonite and its modified form) by electrochemical impedance spectroscopy, it has been shown that the presence of strong proton-conducting properties of the substrate accelerates the conversion of a proton-donor subst...

The possibility of applying the method of SEI in modeling and diagnosing the properties of multiphase systems, including aqueous and non-aqueous electrolytes of complex composition, the solid electrolyte membranes, etc., are shown.

The authors investigated the possibility of generation of hydrogen peroxide in seawater of various salinity under mechanochemical effects. Electrochemical methods determined inhomogeneities of the seawater structure. Proposed is possible mechanism of generation of H2O2 at multiple interfaces both in the complex electrolyte and in the presence of th...

Tetramethylammonium bis(salicylo)borate was prepared via exchange reactions in alkaline solution. The purity and structure of the samples obtained were characterized by thermal gravimetric analysis and NMR. The electrochemical stability and electrical conductivity of solutions of tetramethylammonium bis(salicylo)borate in acetonitrile and propylene...

On studies of the adsorption of the enzyme composition of Raphanus sativus L. Var. niger on substrates with different acid-base properties (bentonite and its acid modified form) it was shown that by controlling electron or proton conductivity of the substrate the redox – activity of the immobilized native enzyme could be controlled. By the calculat...

The synthesis of Na-, K-, Rb-, Cs - bis(oxalato)borates (NaBOB, KBOB, RbBOB and CsBOB) was carried out by microwave method. Application of the method allowed to shorten the synthesis duration in 8-10 times and to obtain the product with the product yield near to quantitative. The structure of compounds was proved by IR- and NMR - spectroscopy, the...

We have measured the maximum ionic conduction in distilled water of hydrated compounds based on ZrO2 containing as the second component zirconium phosphate, zirconium phosphomolybdenum acid as well as hydrated aluminum oxide in a maximum saturated form after absorption of Cu(II) ions. The conduction value of ion–exchange materials constitutes 0.01–...

The influence of the chemical composition of water on the rate of volatilization and degradation of trichloroacetic acid (TCA) has been investigated. The schemes of possible secondary pollution of territories adjacent to the polluted water bodies were discussed on the basis of measuring the surface tension, TCA distribution in solution, and the ana...

The peculiarities of the stepwise preparation of cryoconcentrates from grape must (test) and liqueurs from sugar (control) used in sparkling wine production via electrochemical impedance spectroscopy is considered. The application of a measuring system with platinum electrodes and models considering the heterogeneity of the electrode’s surface in e...

Overview of the state-of-art representations of water structure and its electrical conductivity are given from the standpoint of its heterogeneous structure. The water structure is fractal, it has water molecules coupled together in clusters with some variable quantity. Clusters are alternating with voids (holes). Basic structural element of cluste...

The existence of supramolecular complex with the dissolved oxygen in water which is a source of hydrogen peroxide generation is theoretically and experimentally proved. Formation of such paramagnetic complex is accompanied by significant propagation of water conductivity (up to 4 orders) and fixed on electrochemical impedance spectra as inductive i...

The conductivity of distilled water and dilute electrolyte solutions in the presence and absence of dissolved oxygen is studied. It is found that the circuit can be implemented with equal probability as a capacitive circuit with physically different current carriers and as an inductive circuit in water and dilute aqueous solutions of oxygen-contain...

Electrochemical Impedance Spectroscopy (SEI) is a modern tool for basic and applied studies of solid and liquid materials with ionic, mixed ionic-electronic conductivity, semiconductors and even insulators. SEI is used to study the charge transfer in heterogeneous systems with interphase boundaries, electrode/electrolyte interphases, as well as ele...

When studying the electrochemical properties of diluted suspensions of natural and modified bentonite, the correlation between the inductive component of the system’s resistance and the temperature has been established. It confirms the hypothesis on the presence of paramagnetic particles in the system, whose solubility decreases with the growth of...

The paper has investigated adsorption of peat fulvic acids from distilled and tap water on activated carbons with different chemistry of the surface when using potentiometric control. It has been shown that water purification of fulvic acids is most expedient on activated carbons having passed “soft” oxidizing treatment. This is enhanced by the cha...

The influence of water to increase the number of charge carriers in dilute suspensions of modified phosphate ions of bentonite is shown. Experimentally established the existence of a high redox potential in such systems. Shows the difference in the redox properties of suspensions of natural and modified bentonite. Kinetic studies have established t...

Problems of basin self-remediation and its control are discused

The participation of water in the formation of the multicomponent double electric layer (DEL) on the electrode is experimentally fixed at the presence of the dispersion of alumosilicate. The equivalent circuit of DEL formation in the frame structures saturated with water containing hydroxyl groups and oxides of polyvalent metals in the channels of...

In this paper we propose a model that clarifies the mechanism of formation of active oxidizing agents on the measuring electrode and the bulk of the solution in the presence of dissolved oxygen and ions of polyvalent metals, which explains the reason to an error of measurement of the redox potential of natural water

We have conducted potentiometric and voltamperometric research of strongly diluted aqueous solutions of electrolytes in stationary and dynamic conditions. We have found a mechanochemical effect on the readings of a standard redox electrode in model solutions and natural waters, which is absent in degassed solutions. Cyclic voltamperometric investig...

We have considered the evolution of idea about electric conductivity and basic-acidic properties of liquid water based on the data of its cluster structure. We have also discussed the mechanisms of conductivity in the presence of different ions and the impact of physical fields on electrical conductivity and the pH status of water.

It has been shown that within a broad interval of the rates of the electrolyte flow in a fluidized bed of inert particles the mass transfer rate of electroreduction of ions of nonferrous metals varies insignificantly. Based on the constancy of the flow rate of the electrolyte in the bulk of the fluidized bed of inert particles we have proposed a si...

On the example of kinetics of phenols transformation in natural waters in conditions of weak mineralization the model for the mass-transfer calculations in presence of interphase boundaries, merging the principle of quasi-stationary state for calculation of limiting stages of chemical processes in homogeneous medium with kinetic parameters of sorpt...

The fundamentals of electrochemical ion-exchange process control in flow-through and dynamic beds of ion-exchange materials are recovered. The applica-tion of current on the bed of inorganic ion-exchanger particles with protonic con-ductivity is shown to allow the effective adsorption and desorption of non-ferrous metal ions.

The state-of-the-art in red-ox models of natural water, estimating in a whole the system of oxidizing and reducing agents discussed. Criteria of the choice of basic potential - determining components is given. The deficiency of all existing models in the absence of the account of the effect of рН values on forms of the presence of metal ions of var...

The effect of solution acidity, particle size and impurity exchange Fe3+ cations of montmorillonite on its acid-base and catalytic properties in water solutions is investigated. The effect of hydrolytic processes on the amount of hydroxide groups in the composition of the mineral, reinforcing the adsorption properties and creating an opportunity of...

The brief overview of results obtained on electrochemical control in adsorption phenomena on carbon electrodes presented. As the examples, adsorption of phenol, benzoic acid and chloroform on the fixed flow-through beds of granulated and fiber carbon materials studied. The ability of surface charge control on electrochemically controlled adsorption...

The study of adsorptive and chemical immobilization of beta-cyclodextrin on a surface of hydroxylated silicas with various porous structure is described. Using IR spectroscopy, thermal gravimetrical analysis with a programmed heating, and chemical analysis of the silica surface, it is shown that the process of adsorption-desorption of beta-cyclodex...

The synthesis of mono-tosyl-beta-cyclodextrin (Ts-beta-CD) and its attachment to the surface of aminopropylsilica are reported. The resulting material was characterized by IR spectroscopy, elemental analysis, and quantitative evaluation of the surface compounds. The maximum amount of beta-cyclodextrin (beta-CD) grafted on the surface of silica was...

Some fundamentals and applications of electrochemical systems containing 3—dimensional electrode systems with dynamic matrix, fluidized beds, consisting of particles possessing different conductivity, namely: nonconductive (glass or plastics), conductive (metal granules), semi-conductive (various carbon materials) and ion conductive (ion exchangers...

The diffusion coefficients of Ni2+ and H+ in macroporous cation-exchange resin were determined. It was shown that the ion mobility grows with increase in a superficial solution flow rate. The Ni2+ and H+ diffusion coefficients were found to be 2.33·10-12 and 1.76·10-11 m2/s at the flow rate of 2·10-3 m/s.

Comparison of values of the mobility designed from specific conductivity and a migration in ion exchange materials of the various nature, both industrially released organic, and inorganic, based on the amorphous zirconium phosphate. For the majority of materials mobility makes 1,0-5,0·10-11m2·B-1 ·c-1. Proceeding from operational advantages of inor...

In the paper, the activity of the Department of Chemical and Information Analysis of the Vernadskii Institute of General and Inorganic Chemistry, National Academy of Sciences of Ukraine, is discussed. It is shown that the presence of a full spectrum of information services allowed the successful international cooperation of the researchers. It is n...

The effect of an external electric field on the sorption processes occurring on the materials with different types of conductivity (carbonaceous adsorbents, proton-conductive materials, and composite carbon-oxide sorbents) was studied. A possibility to optimize the sorption process and to carry out the multiple adsorption-desorption cycles was esta...

The effect of particle-wall collision on the mass transfer rate mechanism in liquid fluidized bed electrochemical cells was studied. Collision frequencies and currents were measured at microelectrodes set in the bed wall. It is postulated that, at each particle–electrode collision, a specific microvolume of bulk concentration electrolyte is introdu...

The mass transfer rate in fluidized beds of inert particles (FIB) is shown to be dependent on the electrolyte flow velocity and the intensity of particle collisions with the electrode. The influence of particle size and density on the ratio of the magnitude of these two influences on the mass transfer rate in a FIB was studied. Use of particle mate...

A comparative analysis of electrochemical cells containing fluidized-bed electrodes (FBEs) is made. The influence of the arrangement of the working space on the manner of particle movement and distribution of polarization inside of the FBE is taken into account. The configuration of the FBE working space is chosen in accordance with the hydrodynami...

Fluidized bed electrochemical reactors with nonconducting (glass, sand or plastics granules), conducting (metal or metal-coated granules), semiconductor (different carbon materials), and ion conductive (ion-exchange resins or inorganic ion exchangers) are widely studied and used for different separation processes. Each type of fluidized bed electro...

A study of the sorption of d-metal ions by titanium phosphate on a platinum electrode shows that the potential of the platinum electrode significantly influences the uptake of cations by the ion-exchanger. Cathodic polarization leads to a significant increase of the sorption whereas anodic polarization is accompanied by desorption. Therefore it is...

The data on the rate of mass transfer towards electrodes in the fluidized layer of non-conducting grains are analyzed, as well as the frequencies and amplitudes of grain-electrode single collisions, are considered. The contribution of collision current in the mass transfer rate is confirmed quantitatively. The equation yielded to calculate a single...

The mode of carbon material synthesis and treatment gives the possibility of varying electrode zero charge potential (ZCP), acid-base properties and surface charge in a wide range. This is induced by different carbon matrix perfections and modification of it by heteroatoms and surface groups. The dependence of surface charge and the electrode poten...

Zero charge potentials and electrode potentials in electrolyte solutions for oxidized activated carbons of different origin, are measured. Quantum-mechanical calculations of carbon matrix energies for different surface functional groups, are carried out. Ion exchange on oxidized carbon occurs not only by local interactions with functional groups, b...

Dicyanoargentate ion adsorption from electrolytes imitated Ag ore leaching solutions on carbon matrix of different perfection is studied. Ag sorption kinetics and time dependences of carbon electrode potential are investigated. Carbon surface pretreatment influence is considered in terms of oxygen electrode theory. Ca ion presence in system causes...

Regularities of the mass transfer to a plane electrode in a fluidized bed of glass particles during the electrochemical reduction of silver were studied at various rates of the flow of electrolyte, various sizes of particles of the layer, and compositions of the electrolyte. Coefficients of mass transfer, limiting currents of the silver reduction w...

The possibility of palladium and tin combined electrodeposition on solid electrode has been examined by voltammetry and preparative electrolysis. The process has been carried out using hydrochloric solutions and pseudo-liquid layer of glass particles. Polarization curves for Sn(IY) → Sn(II), Sn(II) → Sn(0) reduction with and without Pd(II) in the s...

The electron-donor properties of ordinary and modified activated carbons were compared on the basis of quantum-chemical calculations and electrochemical investigations. The mechanisms of the effect of heteroatoms and functional groups on the aromatic system of the carbon matrix were shown on the electronic level.

A comparative investigation of zero-charge potentials (ZCP) of activated carbons of different origin in the acidity range of 2 ≤ pH ≤ 11 was carried out by the method of potentiometric titration under isoelectric conditions. ZCP of carbons in the absence of electrochemically active gases are only realized in the region of average pH values (4-9). T...

In studies of the mechanism of action of CHS on biological fluids their electrochemical properties (sign of the surface charge and value of the electrode potential) have been almost entirely disregarded. In view of this, the authors carried out a study of the kinetics of formation of the electrode potentials of a number of CHS made from IGI and SKT...

An analytical expression for mass-transport rate to fluidized-bed electrodes is derived from results obtained when examining mass transport to a single sphere in flowing electrolyte, and allowing for the laws of flow past the particles and the goodness of fit of different computed and experimental data is demonstrated.

The distribution of polarization of the metallic phase of pseudofluidized electrodes (PFE) of different heights was examined upon electrolytic reduction of copper ions from acidic sulfate solutions, containing 3 multiplied by (times) 10** minus **3 mole/l of Cu. It was shown that in the general case reduction of copper ions of PFE occurs in a mixed...