TY - JOUR
T1 - Mobile ion partitioning in ion exchange membranes immersed in saline solutions
AU - Yu, Yue
AU - Yan, Ni
AU - Freeman, Benny D.
AU - Chen, Chau-Chyun
N1 - Funding Information:
Funding support is provided by the U. S. Department of Energy under the grant DE-EE0007888 . The authors gratefully acknowledge the financial support of the Jack Maddox Distinguished Engineering Chair Professorship in Sustainable Energy sponsored by the J.F Maddox Foundation .
Funding Information:
Funding support is provided by the U. S. Department of Energy under the grant DE-EE0007888. The authors gratefully acknowledge the financial support of the Jack Maddox Distinguished Engineering Chair Professorship in Sustainable Energy sponsored by the J.F Maddox Foundation.
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/2/15
Y1 - 2021/2/15
N2 - Ion exchange membranes (IEMs) are extensively used in separation and energy storage systems. Prior studies have suggested that rigorous thermodynamic modeling is essential to describe mobile ion partitioning in IEMs, especially weakly charged ionic membranes, immersed in aqueous salt solutions. Based on a recently developed polyelectrolyte nonrandom two-liquid (NRTL) activity coefficient model, this work presents a thermodynamic analysis for the mobile ion partitioning between external salt solutions with ionic strength from 0.01 to 1 molal and membranes of poly (ethylene glycol diacrylate) (PEGDA) copolymerized with 2-acrylamido-2-methylpropanesulfonic acid (AMPS). We show that mobile ion partitioning in the uncharged membranes and the weakly charged membranes immersed in saline solutions is controlled by the long-range “point-to-point” electrostatic interactions and the short-range van der Waals interactions in the membrane phase. For the strongly charged membrane samples, the long-range “point-to-line” electrostatic interactions also play a role, the mobile ion mean ionic activity coefficients are close to unity, and the ion sorption data may be qualitatively interpreted with either the ideal Donnan equilibrium model or Manning's limiting law.
AB - Ion exchange membranes (IEMs) are extensively used in separation and energy storage systems. Prior studies have suggested that rigorous thermodynamic modeling is essential to describe mobile ion partitioning in IEMs, especially weakly charged ionic membranes, immersed in aqueous salt solutions. Based on a recently developed polyelectrolyte nonrandom two-liquid (NRTL) activity coefficient model, this work presents a thermodynamic analysis for the mobile ion partitioning between external salt solutions with ionic strength from 0.01 to 1 molal and membranes of poly (ethylene glycol diacrylate) (PEGDA) copolymerized with 2-acrylamido-2-methylpropanesulfonic acid (AMPS). We show that mobile ion partitioning in the uncharged membranes and the weakly charged membranes immersed in saline solutions is controlled by the long-range “point-to-point” electrostatic interactions and the short-range van der Waals interactions in the membrane phase. For the strongly charged membrane samples, the long-range “point-to-line” electrostatic interactions also play a role, the mobile ion mean ionic activity coefficients are close to unity, and the ion sorption data may be qualitatively interpreted with either the ideal Donnan equilibrium model or Manning's limiting law.
KW - Ion exchange membrane
KW - Ion sorption
KW - Manning's limiting law
KW - Mobile ion partition
KW - Polyelectrolyte NRTL Model
UR - http://www.scopus.com/inward/record.url?scp=85094609445&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2020.118760
DO - 10.1016/j.memsci.2020.118760
M3 - Article
AN - SCOPUS:85094609445
VL - 620
JO - Journal of Membrane Science
JF - Journal of Membrane Science
SN - 0376-7388
M1 - 118760
ER -