Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current Modes

The study of ion transport in membrane systems in overlimiting current modes is an important problem of physical chemistry and has an important application value. The influence of the space charge on the transport of salt ions under overlimiting current modes was first studied in the work of Rubinst...

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Main Authors: Makhamet Urtenov, Natalia Chubyr, Vitaly Gudza
Format: Article
Language:English
Published: MDPI AG 2020-08-01
Series:Membranes
Subjects:
Online Access:https://www.mdpi.com/2077-0375/10/8/189
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author Makhamet Urtenov
Natalia Chubyr
Vitaly Gudza
author_facet Makhamet Urtenov
Natalia Chubyr
Vitaly Gudza
author_sort Makhamet Urtenov
collection DOAJ
description The study of ion transport in membrane systems in overlimiting current modes is an important problem of physical chemistry and has an important application value. The influence of the space charge on the transport of salt ions under overlimiting current modes was first studied in the work of Rubinstein and Shtilman and later in the works of many authors. The purpose of this research is to study, using the method of mathematical modeling, the reasons of formation and properties of the local maximum (minimum) space charge in membrane systems under overlimiting current conditions. It is shown that, in the diffusion layer of the cation-exchange membrane (CEM), the local maximum of the space charge appears due to the limited capacity (exchange capacity) of the membrane at a given potential jump, i.e., the local maximum of space charge appears due to the presence of a local minimum of space charge at the surface of the CEM. The local maximum of the space charge moves as a single soliton-like wave into the depth of the solution. Unlike real solitons, this charged wave changes its size and shape, albeit quite slowly. In the section of the desalination channel, the situation is completely different. First, the space charge of the anion-exchange membrane (AEM) has a negative value, so we should be talking about the local minimum (or the maximum of the absolute value of the charge). However, this is an insignificant clarification. Secondly, the space charge waves of different signs begin to interact, which leads to a new effect, namely the effect of the breakdown of the space charge. The dependence of the local maximum on the input parameters—the cation diffusion coefficient, the growth rate of the potential jump, and the initial and boundary concentrations—is studied.
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spelling doaj.art-574ac1106d4f47419282f557fab553682023-11-20T10:19:40ZengMDPI AGMembranes2077-03752020-08-0110818910.3390/membranes10080189Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current ModesMakhamet Urtenov0Natalia Chubyr1Vitaly Gudza2Department of Applied Mathematics, Kuban State University, Krasnodar 350040, RussiaDepartment of Applied Mathematics, Kuban State Technological University, Krasnodar 350042, RussiaDepartment of Applied Mathematics, Kuban State University, Krasnodar 350040, RussiaThe study of ion transport in membrane systems in overlimiting current modes is an important problem of physical chemistry and has an important application value. The influence of the space charge on the transport of salt ions under overlimiting current modes was first studied in the work of Rubinstein and Shtilman and later in the works of many authors. The purpose of this research is to study, using the method of mathematical modeling, the reasons of formation and properties of the local maximum (minimum) space charge in membrane systems under overlimiting current conditions. It is shown that, in the diffusion layer of the cation-exchange membrane (CEM), the local maximum of the space charge appears due to the limited capacity (exchange capacity) of the membrane at a given potential jump, i.e., the local maximum of space charge appears due to the presence of a local minimum of space charge at the surface of the CEM. The local maximum of the space charge moves as a single soliton-like wave into the depth of the solution. Unlike real solitons, this charged wave changes its size and shape, albeit quite slowly. In the section of the desalination channel, the situation is completely different. First, the space charge of the anion-exchange membrane (AEM) has a negative value, so we should be talking about the local minimum (or the maximum of the absolute value of the charge). However, this is an insignificant clarification. Secondly, the space charge waves of different signs begin to interact, which leads to a new effect, namely the effect of the breakdown of the space charge. The dependence of the local maximum on the input parameters—the cation diffusion coefficient, the growth rate of the potential jump, and the initial and boundary concentrations—is studied.https://www.mdpi.com/2077-0375/10/8/189ion-exchange membranemathematical modellingusing overlimiting current modesmembrane systemscation-exchange membraneeffect of the breakdown of the space charge
spellingShingle Makhamet Urtenov
Natalia Chubyr
Vitaly Gudza
Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current Modes
Membranes
ion-exchange membrane
mathematical modelling
using overlimiting current modes
membrane systems
cation-exchange membrane
effect of the breakdown of the space charge
title Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current Modes
title_full Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current Modes
title_fullStr Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current Modes
title_full_unstemmed Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current Modes
title_short Reasons for the Formation and Properties of Soliton-Like Charge Waves in Membrane Systems When Using Overlimiting Current Modes
title_sort reasons for the formation and properties of soliton like charge waves in membrane systems when using overlimiting current modes
topic ion-exchange membrane
mathematical modelling
using overlimiting current modes
membrane systems
cation-exchange membrane
effect of the breakdown of the space charge
url https://www.mdpi.com/2077-0375/10/8/189
work_keys_str_mv AT makhameturtenov reasonsfortheformationandpropertiesofsolitonlikechargewavesinmembranesystemswhenusingoverlimitingcurrentmodes
AT nataliachubyr reasonsfortheformationandpropertiesofsolitonlikechargewavesinmembranesystemswhenusingoverlimitingcurrentmodes
AT vitalygudza reasonsfortheformationandpropertiesofsolitonlikechargewavesinmembranesystemswhenusingoverlimitingcurrentmodes