Name
Zabolotskiy Victor Ivanovich
Scholastic degree
•
Academic rank
professor
Honorary rank
—
Organization, job position
Kuban State University
Web site url
—
—
Articles count: 11
The stability of strongly basic anion-exchange membranes MA-41-2P (JSC "Schekino-Nitrogen", Russia) and AMX (Tokuyama Soda, Japan) under intensive current regimes was investigated in the
current study. The process of water molecules dissociation at current densities above the limiting one in 0.01 M sodium chloride solution was studied in detail. The length of the electroconvective instability at the membrane / solution interface at currents
exceeding the limiting current was measured by laser interferometry
The results of study of bipolar membrane – analogue
of MB-2, modified with chemically introduced chromium
(III), iron (III) and nickel (II) hydroxides by the
method of frequency spectrum of electrochemical impedance,
by infrared spectroscopy and scanning electron
microscopy in combination with X-ray spectrum
analysis are presented. It is shown, that sequential
treatment of cation-exchanger, contained in cationexchange
membrane, with metal salt solution and alkali
solution does not result in formation of complex
compounds of these metals with ionic groups of ion
exchanger. It was found that in these conditions the
presence of heavy metals in the phase of cationexchanger
confirmed by X-ray analysis, however,
crystals of hydroxides of heavy metals are not detected
in the size range of 1000 nm to 20 nm. These heavy
metal compounds are thermally unstable and their
catalytic activity in the reaction of dissociation of water
molecules decreases with increasing temperature
during heat treatment. The introduction of low-soluble
hydroxides of d-metals (chromium (III), iron (III),
nickel(II)) by chemical method can significantly improve
the electrochemical characteristics of a bipolar
membrane. The most effective catalysts in water dissociation
reaction are the hydroxides of chromium (III)
and iron (III) and, as a consequence, membranes with
these hydroxides have a lower value of overpotential
compared with original membrane at the same current
density
The article discusses results of experimental research
of the influence of aprotic and proton solvents on reaction
rate of water molecules dissociation in the bipolar
membrane MB-1 by the method of electrochemical
impedance frequency spectrum. It was discovered, that
addition of organic component in aqueous solutions results
in significant influence on the parameters of water
dissociation in a bipolar region of the membrane.
The reason for this influence is the reduction of the
mass fraction of water in solution and, consequently,
in a bipolar region of the membrane, which itself reduces
the rate of the dissociation reaction. Another
reason for the influence of the organic solvent is its effect
on the network of hydrogen bonds existing in water
and aqueous solutions. Depending on the nature of
organic solvent and its concentration, the network of
hydrogen bonds may be strengthened, or destroyed,
thus facilitating removal of the proton involved in the
reactions between water molecules and catalytic centers
in cation-exchange and anion-exchange layer of
bipolar membrane, or retarding removal of proton.
This leads respectively to speed up or slow down the
rate of dissociation in the bipolar region of the membrane,
as well as changing the constants of the dissociation
reaction of water. Introduction of organic solvent
in solutions, which are in the contact with bipolar
membrane, is a convenient method of investigating the
role of solution composition on the rate of proton
transfer between water molecules and catalytic centers
in the membranes
This work is a continuation of [1], which was devoted to
the investigation of the hydrodynamics of the experimental electrochemical cell with rotating disk cation exchange membrane. This article focuses on the transport of salt ions in a closed cell at different initial experimentation with modes of exact current regimes. The main regularities of transport of salt ions and membrane equal accessible surface were set
The article presents a mathematical model of the ion transport across phase boundary exchange membrane / solution. The border is considered as an object in space, endowed with all the physical and chemical properties that are inherent physical and chemical phases. It is regarded as a special physical and chemical environment, having a distributed exchange capacity in which there is space charge dissociation of water molecules. The size of this object is estimated in the range of 1-300 nm. The surface morphology of industrial membrane type MK-40, ÐœA-41 and ÐœA-41P was investigated experimentally by scanning electron microscopy (REM). There was analyzed the amplitude of average surface roughness. In this article, the reaction layer is modeled as a region that forms as a relief morphology of the membrane. Membrane properties are due to the properties of the solution and the properties of the membrane. To determine the dependence of Q(x) is proposed procedure for assessing the proportion of solid phase in the total volume of which can be seen in the vertical cross section microprofile on the membrane surface line. Height multivendors determine the reaction layer zone on frame of model. Influence of surface morphology on the V-A characteristics and the sizes of the convective instability of cation-exchange membrane evaluated numerically simulating the hydrodynamic flow conditions using a solution of the Navier-Stokes equations. The transfer of a strong electrolyte such as NaCl ions through the thin layer of the reaction layer is considered. The place of nanomodel in the structure of a three-layer membrane system is showed. The distribution of the concentration of ions in the system, the charge density distribution and the dependence of the integrate charge with extent nanolayer is present. How to change the shape of the space charge and its integral value with one is investigated
Theoretically and experimentally, we investigated the
process of adjusting the pH of natural water of
hydrocarbonate class electrodialyzer with bipolar
membranes with channel length of 40 cm. We
experimentally measured concentration of
components, pH of the solutions in alkaline and acid
channels of electrodeposition depending on the current
density. The article describes a mathematical model
for long channels; to scale the mass transfer
characteristics of the process there was applied and
verified a method of compartmentalization, which
gave the possibility to calculate the dependence of the
component along the channel length at different
velocities of flow of the solution. Numerical
calculations were compared with experimental data on
electrodialyser of 10 cm and 40 cm length
This article investigates hydrodynamic of experimental electrochemical cell with rotating disk in the cation exchange membrane. We have also investigated the flow in open, with the free surface of the solution and in hermetically closed cells. The main regularities of the hydrodynamics of the experimental cell at its real size were set
This article continues the works [1,2], devoted to the theoretical study of the basic laws of electroconvection
caused by natural or artificial inhomogeneous conductivity of ion-exchange membranes in a smooth rectangular channel electrodialysis desalination unit. For this purpose, a mathematical model was created for a binary electrolyte electroconvection at overlimiting current modes in the form of a boundary value problem for a coupled system of the Nernst-Planck-Poisson and Navier-Stokes equations. We have studied the influence of heterogeneity on the ion-exchange membranes and ion transport electroconvection salt, calculated currentvoltage characteristic. The possibility of intensification of mass transfer due to the surface modification of ion exchange membranes was also shown
The present work describes the chemical synthesis of
poly-N,N-diallyl pyrrolidinium bromide and polyN,N-diallyl
morpholinium bromide - high-molecular
compounds containing quaternary nitrogen atoms,
which included in two five- and/or six-membered
heterocyclic rings. These polymers are perspective
modifiers for industrially produced anion-exchange
membranes, the use of which should significantly
improve the resistance to degradation of the
membranes at over-limiting current regimes. The
structure of obtained polymers was characterized by
FTIR, 1H and 13C NMR spectroscopy. The optimal
reaction conditions, which increase the yield of desired
products, were defined. It is shown that is preferable to
use 1-butanol as a solvent and benzoyl peroxide as an
initiator
In the article the mathematical model of the space charge region in the bipolar membrane is considered. The structure of the space charge region under passing of electric current, and without electric current is discussed. The results of experimental studies of water dissociation in the bipolar membrane in the presence of chromium(III) are discussed