The effect of an ac sinusoidal perturbation of known amplitude and frequency superimposed on the usual dc applied electric voltage difference on the electroosmotic flow through a typical cation-exchange membrane has been studied using different monovalent electrolytes. As a general trend, the presence of the ac perturbation increases the value of the electroosmotic flow with respect to the value in the absence of ac perturbation. A dispersion of the electroosmotic permeability on the frequency of the applied ac signal has been found for the three studied electrolytes, observing that the electroosmotic permeability reaches maximum values for some characteristic values of the frequency. This behavior may be related to the different relaxation processes in heterogeneous mediums. Copyright 2001 Academic Press.
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http://dx.doi.org/10.1006/jcis.2001.7610 | DOI Listing |
J Phys Chem B
January 2025
Chemical Sciences Department, Homi Bhabha National Institute, Mumbai 400094, India.
This study delves into the interplay of temperature, composition, tortuosity, and electrostatic interactions on ion diffusion within cation exchange membranes. It explores the temperature dependence (16-60 °C) of the self-diffusion coefficients (SDCs) of Ba and Eu ions within the Nafion 117 cation exchange membrane, particularly in the presence of Na ions. Radiotracer techniques and electrochemical impedance spectroscopy were employed to investigate these SDCs.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.
Electrochemical CO reduction in acidic media attracts extensive research attention due to its potential in increasing carbon efficiency. In most reports, alkali cations are introduced to suppress hydrogen evolution and to promote CO reduction. However, the mass transport of alkali cations through cation exchange membrane induces the change of electrolyte compositions.
View Article and Find Full Text PDFNat Commun
January 2025
School of Environment and Energy, State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, South China University of Technology, Guangzhou, 510006, China.
Challenges in CO capture, CO crossover, product separation, and electrolyte recovery hinder electrocatalytic CO reduction (COR). Here, we present an integrated electrochemical recovery and separation system (ERSS) with an ion separation module (ISM) between the anode and cathode of a water electrolysis system. During ERSS operation, protons from the anolyte flow through the anodic cation exchange membrane (CEM) into the ISM, acidifying the COR effluent electrolyte.
View Article and Find Full Text PDFFood Res Int
January 2025
Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Denmark. Electronic address:
The efficiency of ultrafiltration (UF) of acidified skim milk (SM) is impaired by protein aggregation and mineral scaling. The aim of this study is to assess the potential of acidification by electrodialysis with bipolar membranes (EDBM), in comparison with citric acid (CA), prior to the UF process on filtration performance, fouling and composition of the protein concentrates. Electro-acidification, facilitated by a water-splitting reaction, decreased the pH of milk to ∼ 5.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Membrane-assisted direct seawater splitting (DSS) technologies are actively studied as a promising route to produce green hydrogen (H), whereas the indispensable use of supporting electrolytes that help to extract water and provide electrochemically-accelerated reaction media results in a severe energy penalty, consuming up to 12.5 % of energy input when using a typical KOH electrolyte. We bypass this issue by designing a zero-gap electrolyzer configuration based on the integration of cation exchange membrane and bipolar membrane assemblies, which protects stable DSS operation against the precipitates and corrosion in the absence of additional supporting electrolytes.
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