title: Use of Soft Electrodes in Capacitive Deionization of Solutions.
abstract: All efforts to obtain, reuse or purify water are extremely significant for society. Recently, researchers have begun to delve in an idea born decades ago: the desalination of water using highly porous electrodes. It is based on a fundamental aspect of electrical double layers, namely, their huge capacitance. The ions of a solution can be partially removed under the application of an electric field when the solution fills the space between porous electrodes, either bare (CDI, or capacitive deionization), coated with ionic exchange membranes (MCDI) or chemically treated (inverted-CDI or i-CDI). One of the challenges of the last years was to explore new materials and arrangements to improve the efficiency of the system. In this work, we propose a new approach inspired in the electrokinetics of soft particles: a layer of polyelectrolyte (cationic on one electrode, anionic on the opposite one) coats the carbon electrodes, converting them in a sort of "soft" electrode pair. We present a theoretical model and a set of experiments showing how soft electrodes can be successfully employed in capacitive deionization.
authors.affiliation: Department of Applied Physics, School of Science, Campus Fuentenueva University of Granada , 18071 Granada, Spain.
authors.forename: Silvia
authors.identifier: http://orcid.org/0000-0002-7329-0817
authors.initials: S
authors.lastname: Ahualli
authors.affiliation: Department of Applied Physics, School of Science, Campus Fuentenueva University of Granada , 18071 Granada, Spain.
authors.forename: Guillermo R
authors.initials: GR
authors.lastname: Iglesias
authors.affiliation: Department of Applied Physics, School of Science, Campus Fuentenueva University of Granada , 18071 Granada, Spain.
authors.forename: María M
authors.initials: MM
authors.lastname: Fernández
authors.affiliation: Department of Applied Physics, School of Science, Campus Fuentenueva University of Granada , 18071 Granada, Spain.
authors.forename: María L
authors.identifier: http://orcid.org/0000-0002-5185-0465
authors.initials: ML
authors.lastname: Jiménez
authors.affiliation: Department of Applied Physics, School of Science, Campus Fuentenueva University of Granada , 18071 Granada, Spain.
authors.forename: Ángel V
authors.initials: ÁV
authors.lastname: Delgado
mesh_terms: D002244:Carbon; D025802:Electric Capacitance; D004566:Electrodes; D016062:Porosity; D018508:Water Purification
chemical_list: D002244:Carbon