How bulk and surface properties of sulfonated cation-exchange membranes response to their exposure to electric current during electrodialysis of a Ca2+ containing solution

Titorova, Valentina; Moroz, Ilya A.; Mareev, Semyon; Pismenskaya, Natalia; Саббатовский, К. Г.; Wang, Y.; Xu, Tongwen; Nikonenko, Victor

doi:10.1016/j.memsci.2021.120149

Cited by 18 publications

(4 citation statements)

References 69 publications

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“…As a result, the section of negative conductivity on the CVC practically disappears (insert in Figure 9 a). Small vortices developing by the mechanism of “electroosmosis I” begin to rotate in the opposite direction and prevent the development of non-equilibrium electroconvection [ 93 ]. It is known [ 90 ] that carboxylic groups have exhibit highly catalytic activity towards water splitting.…”

Section: Resultsmentioning

confidence: 99%

Comparison of the Electrodialysis Performance in Tartrate Stabilization of a Red Wine Using Aliphatic and Aromatic Commercial and Modified Ion-Exchange Membranes

et al. 2023

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The application of electrodialysis for tartrate stabilization and reagent-free acidity correction of wine and juices is attracting increasing interest. New aliphatic membranes CJMC-3 and CJMA-3 and aromatic membranes CSE and ASE were tested to determine their suitability for use in these electrodialysis processes and to evaluate the fouling of these membranes by wine components for a short (6–8 h) operating time. Using IR spectroscopy, optical indication and measurement of surface contact angles, the chemical composition of the studied membranes, as well as some details about their fouling by wine components, was clarified. The current–voltage charsacteristics, conductivity and water-splitting capacity of the membranes before and after electrodialysis were analyzed. We found that in the case of cation-exchange membranes, complexes of anthocyanins with metal ions penetrate into the bulk (CJMC-3) or are localized on the surface (CSE), depending on the degree of crosslinking of the polymer matrix. Adsorption of wine components by the surface of anion-exchange membranes CJMA-3 and ASE causes an increase in water splitting. Despite fouling under identical conditions of electrodialysis, membrane pair CJMC-3 and CJMA-3 provided 18 ± 1 tartrate recovery with 31 · 10−3 energy consumption, whereas CSE and ASE provided 20 ± 1% tartrate recovery with an energy consumption of 28 · 10−3 Wh, in addition to reducing the conductivity of wine by 20 ± 1%. The casting of aliphatic polyelectrolyte films on the surface of aromatic membranes reduces fouling with a relatively small increase in energy consumption and approximately the same degree of tartrate recovery compared to pristine CSE and ASE.

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Section: Resultsmentioning

confidence: 99%

Comparison of the Electrodialysis Performance in Tartrate Stabilization of a Red Wine Using Aliphatic and Aromatic Commercial and Modified Ion-Exchange Membranes

et al. 2023

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“…In our model, the thickness of each cation-exchange modification layer was taken equal to 50 nm. The thickness of each anion-exchange modification layer was taken equal to 5 nm, being approximately comparable with the layer of Ca 2+ ions adsorbed on the surface of ion-exchange membranes [46]. Such a layer has a charge of opposite sign with respect to the sub- strate membrane and can potentially increase its specific permselectivity to the transport of singly charged ions.…”

Section: Parameters Of the Substrate Membrane And Modification Layersmentioning

confidence: 99%

“…Since the concentration of fixed ion groups in such layer Q AEL can not be sufficiently precisely estimated, it is assumed in our model as a parameter variable within a range of 5-10 mol/L of a pore solution (i.e., the pore space fraction filled with a charged solution is approximately 1/3 and, therefore, the concentration of fixed groups per 1 L of membrane volume is multiplied by 3). The lower limit (5 mol/L) was estimated from the experimental data on the zeta-potential ζ of the CMX substrate membrane, on which Ca 2+ were adsorbed [46]. According to these data, ζ changes from -28.3 to +48 mV after 12 h of membrane operation in a CaCl 2 solution to evidence not only the change of the charge sign, but also an essential increment in the surface charge by absolute value.…”

Section: Parameters Of the Substrate Membrane And Modification Layersmentioning

confidence: 99%

Mathematical Modeling of the Selective Transport of Singly Charged Ions Through Multilayer Composite Ion-Exchange Membrane during Electrodialysis

Gorobchenko

Gil²,

Nikonenko³

et al. 2022

Membr. Membr. Technol.

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The deposition of several alternating anion- and cation-exchange surface layers (layer-by-layer method) is a promising technique for the modification of ion-exchange membranes, which makes it possible to essentially increase their selectivity to singly charged ions. This paper presents a one-dimensional model, which is based on the Nernst–Planck–Poisson equations and describes the competitive transfer of singly and doubly charged ions through a multilayer composite ion-exchange membrane. It has been revealed for the first time that, as in the earlier studied case of a bilayer membrane, the dependence of the specific permselectivity coefficient (P1/2) of a multilayer membrane on the electrical current density passes through a maximum $$\left( {P_{{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0em} 2}}}^{{\max }}} \right).$$ It has been shown that an increase in the number of nanosized modification bilayers n leads to the growth of $$P_{{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0em} 2}}}^{{\max }},$$ but the flux of a preferably transferred ion decreases in this case. It has been established that $$P_{{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0em} 2}}}^{{\max }}$$ is attained at underlimiting current densities and relatively low potential drop. The simulated dependences $$P_{{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-0em} 2}}}^{{\max }}$$(n) qualitatively agree with the known literature experimental and theoretical results.

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“…First theoretically developed by Rubinstein et al, − electroconvection is experimentally observed as vortices in the ion depletion layer at the membrane/solution interface under overlimiting currents . The physical origin of electroconvection has been attributed to electro-osmosis and the formation of the extended space charge region at ion-selective surfaces. , A variety of setups with different membranes, − resin contents, and electrodes/electrolyte chemistries − have been used in experimental studies to date. The choice of electrode/electrolyte determines the electrochemical reactions (e.g., water splitting, electrodeposition) occurring in the system, which may directly influence the onset and/or nature of electroconvection.…”

Section: Introductionmentioning

confidence: 99%

Influence of Concentration Gradients on Electroconvection at a Cation-Exchange Membrane Surface

Wang,

Chun,

Subban

2024

Langmuir

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Membrane-based systems, such as electrodialysis, play an important role in desalination and industrial separation processes. Electrodialysis uses alternating anion-and cationexchange membranes with a perpendicular electric field to generate concentrated and diluate streams from a feed solution. It is known that under overlimiting current conditions, reduced charge and mass transfer at the membrane interface leads to regions of high ion depletion generating instability and vortices termed electroconvection. While electroconvective mixing is known to directly impact the separation efficiency of electrodialysis, the influence of ion concentration gradients across the membrane experienced in a functional electrodialysis system is not known. Here, we report the influence of ion concentration gradients across a cation exchange membrane (Nafion) that is both aligned with and opposed to the applied electric field. Experiments were conducted by coflowing NaCl solutions of different concentrations (0.1−100 mM) on each side of the membrane, and electroconvection was visualized with a fluorescence dye (Rhodamine 6G). We obtained concentration profiles from fluorescence image data and systematically measured the thickness of the depletion boundary layer d BL under different conditions. We found smaller d BL values at a higher flow rate both with and without concentration gradients. Our results show that electroconvection is enhanced when the electric field is opposite to the direction of the concentration gradient.

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How bulk and surface properties of sulfonated cation-exchange membranes response to their exposure to electric current during electrodialysis of a Ca2+ containing solution

Cited by 18 publications

References 69 publications

Comparison of the Electrodialysis Performance in Tartrate Stabilization of a Red Wine Using Aliphatic and Aromatic Commercial and Modified Ion-Exchange Membranes

Comparison of the Electrodialysis Performance in Tartrate Stabilization of a Red Wine Using Aliphatic and Aromatic Commercial and Modified Ion-Exchange Membranes

Mathematical Modeling of the Selective Transport of Singly Charged Ions Through Multilayer Composite Ion-Exchange Membrane during Electrodialysis

Influence of Concentration Gradients on Electroconvection at a Cation-Exchange Membrane Surface

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