Electrodialysis through nafion membranes coated with polyelectrolyte multilayers yields &gt;99% pure monovalent ions at high recoveries

Ding, Dong; Yaroshchuk, Andriy; Bruening, Merlin L.

doi:10.1016/j.memsci.2022.120294

Cited by 37 publications

(23 citation statements)

References 49 publications

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“…Nowadays, membrane-based separation processes are used to address many problems associated with water resource management, organic and inorganic acid recovery, wastewater treatment, flow batteries, and energy applications. − Electrodialysis (ED), an electric-potential-driven membrane-based separation process, has drawn more attention because of its separation efficacy, ease of application, energy efficiency, and higher water recovery compared to pressure-driven membrane processes like thin film composite nanofiltration and reverse osmosis. − ED stack is composed of an alternate arrangement of anion-exchange membranes (AEMs) and cation-exchange membranes (CEMs) between two electrodes. In recent days, more attention has been given to the preparation of ion-selective ion exchange membranes. − The desire for monovalent selective AEM preparation is one of the trending topics. − The selectivity of AEM through the membrane mainly depends on electrostatic interaction between the fixed charges on the membrane and the co-ions in the solution, the effect of ion channels, and the hydrated size along with the degree of hydration of the anions passing through the AEM. ,− As anions are hydrated in an aqueous solution, their transport in the membrane matrix depends upon the transport of water .…”

Section: Introductionmentioning

confidence: 99%

Cross-Linked, Monovalent Selective Anion Exchange Membrane: Effect of Prealkylation and Co-ions on Selectivity

Sarkar

Patnaik

Mondal

et al. 2023

ACS Appl. Polym. Mater.

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Tuning of hydrophobicity, water uptake, and size of the ion channel is very crucial for the monovalent anion-selective membrane (MASM) preparation. In this work, we report the preparation of MASM from the crosslinked polyacrylonitrile-co-polyvinylimidazole (PAN-co-PVI) copolymer. The copolymer was in situ quaternized and cross-linked using the polyacrylonitrileco-polychloromethylstyrene (PAN-co-PCMSt) copolymer as cross-linker. The benzyl chloride moiety (Ar-CH 2 Cl) of PAN-co-PCMSt reacts with imidazolium nitrogen of PAN-co-PVI and provides a positive charge on the membrane matrix, whereas the PAN moiety provides greater compatibility with the PAN-co-PVI copolymer matrix. The faster cross-linking without external prealkylation forms a strong network structure with a low ionic charge on the membrane surface. Judicious extent of prealkylation followed by crosslinking forms a controlled network structure and small-sized ionic channel with moderate water uptake and good mechanical stability. The representative AEM0Q and AEM17Q membranes with 0 and 17% prealkylation exhibited a permselectivity (P SOd 4 2− Cld − ) value of 4.39 and 15.40, respectively, during the separation of 0.01 M NaCl + 0.01 M Na 2 SO 4 by electrodialysis. Upon further increase of prealkylation to 27 and 32%, the water uptake of the membrane increased, which in turn allowed the passage of SO 4 2− along with Cl − and decreased the P SOd 4 2− Cld − value to 4.12 and 2.45, respectively. Similar trends were observed during the separation of NaCl + MgSO 4 , MgCl 2 + Na 2 SO 4 , and MgCl 2 + MgSO 4 mixtures of each 0.01 M concentration.

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Section: Introductionmentioning

confidence: 99%

Cross-Linked, Monovalent Selective Anion Exchange Membrane: Effect of Prealkylation and Co-ions on Selectivity

Sarkar

Patnaik

Mondal

et al. 2023

ACS Appl. Polym. Mater.

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Section: Introductionmentioning

confidence: 99%

“…Many studies have demonstrated that membranes can effectively separate monovalent and multivalent ions [7][8][9][10][11][12][13]. For example, membranes with a dense, positively charged polyelectrolyte coating showed remarkable Li + /Mg 2+ selectivities around 1000, and electrodialysis with such membranes can recover 60% of the Li + from a source-phase solution while creating 99.9% pure Li + in the receiving phase [7]. The dense structure of the polyelectrolyte film greatly impedes Mg 2+ migration because of its large hydrodynamic radius, and the positive surface charge also excludes multivalent Mg 2+ more than singly charged Li + (Donnan exclusion) [14,15].…”

Section: Introductionmentioning

confidence: 99%

Ion Separations Based on Spontaneously Arising Streaming Potentials in Rotating Isoporous Membranes

2022

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Highly selective ion separations are vital for producing pure salts, and membrane-based separations are promising alternatives to conventional ion-separation techniques. Our previous work demonstrated that simple pressure-driven flow through negatively charged isoporous membranes can separate Li+ and K+ with selectivities as high as 70 in dilute solutions. The separation mechanism relies on spontaneously arising streaming potentials that induce electromigration, which opposes advection and separates cations based on differences in their electrophoretic mobilities. Although the separation technique is simple, this work shows that high selectivities are possible only with careful consideration of experimental conditions including transmembrane pressure, solution ionic strength, the K+/Li+ ratio in the feed, and the extent of concentration polarization. Separations conducted with a rotating membrane show Li+/K+ selectivities as high as 150 with a 1000 rpm membrane rotation rate, but the selectivity decreases to 1.3 at 95 rpm. These results demonstrate the benefits and necessity of quantitative control of concentration polarization in highly selective separations. Increases in solution ionic strength or the K+/Li+ feed ratio can also decrease selectivities more than an order of magnitude.

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“…The producing of membranes with the deposition of alternating anion-and cation-exchange surface layers (layer-by-layer (LbL) method) is promising [14,[32][33][34][35][36][37]. An advantage of this method is very high selectivity attained due to the sequentially alternated Donnan exclusion effect in each layers.…”

Section: Introductionmentioning

confidence: 99%

“…White et al [37] modified the Nafion 115 commercial cationexchange membrane with several alternating layers of poly-4-styrenesulfonate/protonated polyallylamine to attain selectivity in the electrodialysis separation of ions K + /Mg 2+ > 1000. Ding et al [34] have demonstrated that Nafion membranes modified with several films of identical modifiers can separate equimolar K + -Mg 2+ or Li + -Mg 2+ mixtures to obtain a 99.5-% output concentration of singly charged ions. In this case, the current efficiency for such separation is nearly 70%.…”

Section: Introductionmentioning

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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Electrodialysis through nafion membranes coated with polyelectrolyte multilayers yields >99% pure monovalent ions at high recoveries

Cited by 37 publications

References 49 publications

Cross-Linked, Monovalent Selective Anion Exchange Membrane: Effect of Prealkylation and Co-ions on Selectivity

Cross-Linked, Monovalent Selective Anion Exchange Membrane: Effect of Prealkylation and Co-ions on Selectivity

Ion Separations Based on Spontaneously Arising Streaming Potentials in Rotating Isoporous Membranes

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

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