Redox flow deionization using Prussian blue and functionalized ion exchange membrane for enhanced selective ion recovery

Desalination, Год журнала: 2024, Номер 578, С. 117444 - 117444

Опубликована: Фев. 23, 2024

Язык: Английский

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Water content of ion-exchange membranes: Measurement technique and influence on the ion mobility

Journal of Membrane Science, Год журнала: 2024, Номер 698, С. 122538 - 122538

Опубликована: Фев. 14, 2024

Ion-exchange membranes (IEMs) are essential components of several electrochemical water technologies where they promote the transport certain ionic species over others. A characteristic property IEMs concerns their charge density (ICD) which is a key parameter for modeling ion transport. In literature, significant variations in ICD similar reported. We analyzed sources this and traced those back to content measurement. manuscript, we developed new technique measuring content, i.e., via stacking layers membranes. This reduces impact surface film on Using technique, measured CEMs at different counter-ion forms contribution hydration shells inside membrane. The relative change studied counter-ions (K+, Mg2+, or Ca2+) was below 23 % Na+ value. Furthermore, examined relation between volume fraction membrane tortuosity, compared theoretical predictions mobility based Mackie Meares theory values calculated resistance measurements.

Язык: Английский

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Amine-Modified ZIF Composite Membranes: Regulated Nanochannel Interactions for Enhanced Cation Transport and Precise Separation

Environmental Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Фев. 20, 2025

Electromembrane water treatment technologies are attracting attention for their energy efficiency and precise separation of counterions. However, ion-exchange membranes exhibit low ionic conductance selectivity ions with similar charges. In this study, we developed a novel ZIF-8 composite membrane amine-modified nanochannels through an in situ PEI-assisted seeding secondary growth method. An integral uniform selective layer was formed, the induced differential transport Li+, Na+, K+, Mg2+ via dehydration-hydration process. The possessed lower barrier Na+ (Ea = 13 kJ mol-1) compared to 17 mol-1), showing flux 3.7 × 10-8 mol·cm-2·s-1 Na+/Mg2+ permselectivity 52 (∼60 times higher than commercial membrane). physicochemical electrochemical properties were systematically characterized, revealing significant role increasing repulsion facilitating diffusion. Besides, DFT simulation interaction calculation elucidated that moderate binding compensation effect between nanochannels, which can be precisely regulated by PEI incorporation, crucial favorable passage while maintaining high rejection. also demonstrated performance stability during 5-day test maintained across varying salinity pH conditions. This work advances development efficient cation sustainable desalination resource recovery.

Язык: Английский

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Modification of Cation-Exchange Membranes with Polyelectrolyte Multilayers to Tune Ion Selectivity in Capacitive Deionization

ACS Applied Materials & Interfaces, Год журнала: 2020, Номер 12(31), С. 34746 - 34754

Опубликована: Июнь 26, 2020

Capacitive deionization (CDI) is a desalination technique that can be applied for the separation of target ions from water streams. For instance, mono- and divalent cation selectivities were studied by other research groups in context softening. Another focus on removing Na+ recirculated irrigation (IW) greenhouses, aiming to maintain nutrients. This important as an excess has toxic effects plant growth decreasing uptake In this study, we investigated selective sodium (Na+) magnesium (Mg2+) MCDI using polyelectrolyte multilayer (PEM) standard grade cation-exchange membrane (Neosepta, CMX). Alternating layers poly(allylamine hydrochloride) (PAH) poly(styrene sulfonate) (PSS) coated CMX (CMX-PEM) layer-by-layer (LbL) technique. The layer formation was examined with X-ray photoelectron spectroscopy (XPS) static contact angle measurements (SWA) each layer. membrane, i.e., CMX-PEM special-grade CIMS), Na+/Mg2+ selectivity performing experiments, values 2.8 ± 0.2, 0.5 0.04, 0.4 0.1 found, respectively, over up 40 cycles. These indicate flexible switching Mg2+-selective Na+-selective straightforward modification PEM. We anticipate our modular functionalization method may facilitate further development ion-selective membranes electrodes.

Язык: Английский

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Layer-by-layer modification of aliphatic polyamide anion-exchange membranes to increase Cl−/SO42− selectivity

Journal of Membrane Science, Год журнала: 2019, Номер 578, С. 209 - 219

Опубликована: Фев. 16, 2019

Язык: Английский

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