Influence of water content on alkali metal chloride transport in cross-linked Poly(ethylene glycol) diacrylate.2. Ion diffusion

POLYMER

卷:192

Article

Jang, Eui-Soung¹  Kamcev, Jovan¹  Kobayashi, Kentaro¹  Yan, Ni¹  Sujanani, Rahul¹  Dilenschneider, Theodore J.¹  Park, Ho Bum²  Paul, Donald R.¹  Freeman, Benny D.¹ 

[1] Univ Texas Austin, Ctr Mat Water & Energy Syst M WET, McKetta Dept Chem Engn, 2501 Speedway,EERBIdg 4-614, Austin, TX 78712 USA

[2] Hanyang Univ, Dept Energy Engn, Seoul 04763, South Korea

关键词: Alkali metal chlorides;    Diffusion;    Hydrogel;   

DOI  :  10.1016/j.polymer.2020.122316

来源: Elsevier

【 摘 要 】

In this study, the influence of polymer water content on ion diffusion coefficients of alkali metal chlorides (LiCl, NaCl, and KCl) in cross-linked poly(ethylene glycol) diacrylate (XLPEGDA) hydrogels was investigated. This research is part of a broader effort to understand the fundamentals of water and ion transport in hydrated polymers. Salt diffusion coefficients were calculated from salt permeability and sorption measurements. XLPEGDA hydrogels were synthesized with three different water contents (50, 67, and 93 g water/g dry polymer). The diffusion coefficients of alkali metal chlorides in XLPEGDA polymers increased as water content increased. The Mackie and Meares model, which accounts for polymer chain obstruction (i.e., tortuosity) effects on salt diffusion in hydrated polymers, was used to interpret salt diffusion coefficients. The general trend of the experimentally determined salt diffusion coefficients in these polymers is consistent with the model. Individual ion diffusion coefficients in the samples were obtained by combining salt permeability/sorption data with ionic conductivity results. The chloride ion diffusion coefficients were similar for all salts. The relative order of alkali metal ion diffusion coefficients in these polymers was different from that in aqueous solution (i.e., D-K+(s) > D-Na+(s) > D-Li+(s)). Moreover, this order changes as polymer water content varies, suggesting that alkali metal chloride diffusion behavior in XLPEGDA polymers is influenced by both ion hydration and polymer-ion specific interactions.

【 授权许可】

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