Jump to main content
Jump to site search

Issue 8, 2016
Previous Article Next Article

Partitioning of mobile ions between ion exchange polymers and aqueous salt solutions: importance of counter-ion condensation

Author affiliations

Abstract

Equilibrium partitioning of ions between a membrane and a contiguous external solution strongly influences transport properties of polymeric membranes used for water purification and energy generation applications. This study presents a theoretical framework to quantitatively predict ion sorption from aqueous electrolytes (e.g., NaCl, MgCl2) into charged (i.e., ion exchange) polymers. The model was compared with experimental NaCl, MgCl2, and CaCl2 sorption data in commercial cation and anion exchange membranes. Ion sorption in charged polymers was modeled using a thermodynamic approach based on Donnan theory coupled with Manning's counter-ion condensation theory to describe non-ideal behavior of ions in the membrane. Ion activity coefficients in solution were calculated using the Pitzer model. The resulting model, with no adjustable parameters, provides remarkably good agreement with experimental values of membrane mobile salt concentration. The generality of the model was further demonstrated using literature data for ion sorption of various electrolytes in charged polymers, including HCl sorption in Nafion.

Graphical abstract: Partitioning of mobile ions between ion exchange polymers and aqueous salt solutions: importance of counter-ion condensation

Back to tab navigation

Supplementary files

Publication details

The article was received on 05 Nov 2015, accepted on 14 Jan 2016 and first published on 19 Jan 2016


Article type: Paper
DOI: 10.1039/C5CP06747B
Citation: Phys. Chem. Chem. Phys., 2016,18, 6021-6031
  •   Request permissions

    Partitioning of mobile ions between ion exchange polymers and aqueous salt solutions: importance of counter-ion condensation

    J. Kamcev, M. Galizia, F. M. Benedetti, E. Jang, D. R. Paul, B. D. Freeman and G. S. Manning, Phys. Chem. Chem. Phys., 2016, 18, 6021
    DOI: 10.1039/C5CP06747B

Search articles by author

Spotlight

Advertisements