Concentration polarization around polyelectrolyte-coated electrodes. Model and observations Lirio Piñar, Juan Antonio Orozco Barrera, Sergio Delgado Mora, Ángel Vicente Ahualli Yapur, Silvia Alejandra Activated carbon Capacitive deionization Concentration polarization Polyelectrolyte coating Conducting porous particles CDI Financial support of this investigation by FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Spain (Grant No. P20_00233) and Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía, Spain (Grant No. A-FQM492-UGR20) is gratefully acknowledged. Thanks are also due for the grant TED2021-131855BI00/AEI/10.13039/501100011033/Unión Europea Next Generation EU/PRTR. An investigation on the phenomenon of concentration polarization (CP) in conducting porous particles is presented in this work, considering both bare and polyelectrolyte-coated particles. The conducting nature of the porous structure brings about the induction of a surface (and hence volume) charge distribution by the applied external field. The polymer charge (with its counterions from solution) is superimposed on this field-induced component. From the solution of Poisson’s equation, the concentration and potential profiles are evaluated, and from them, the concentration polarization can be calculated. The results are presented as concentration perturbation as a function of time after application of the field, both for bare and coated particles. Experiments are also performed aimed at measuring the CP using a solution of fluorescent dye (rhodamine B). From the increase or decrease of fluorescence, the concentration perturbations are observed around the particle. Importantly, depletion of concentration is observed on both sides of the particle when this is bare. In contrast, if the particles are coated, the classical pattern of a pole of increased concentration and an opposite one of decreased concentration is found. Dielectric dispersion experiments in suspensions of bare and brush-coated particles confirm this fact. 2024-04-24T10:35:53Z 2024-04-24T10:35:53Z 2023-12-15 journal article Published version: Lirio-Piñar, J. A., Orozco-Barrera, S., Delgado, A. V., & Ahualli, S. (2024). Concentration polarization around polyelectrolyte-coated electrodes. Model and observations. Journal of Molecular Liquids, 395, 123757. https://doi.org/10.1016/j.molliq.2023.123757 https://hdl.handle.net/10481/91123 10.1016/j.molliq.2023.123757 spa info:eu-repo/grantAgreement/EC/NextGenerationEU/TED2021-131855BI00 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier