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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Modeling hydration-mediated ion-ion interactions in electrolytes through oscillating Yukawa potentials

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Spaight, John [1] ; Downing, Rachel [1] ; May, Sylvio [1] ; de Carvalho, Sidney J. [2] ; Bossa, Guilherme Volpe [2]
Total Authors: 5
[1] North Dakota State Univ, Dept Phys, Fargo, ND 58108 - USA
[2] Sao Paulo State Univ, Dept Phys, Inst Biosci Humanities & Exact Sci, Sao Jose Do Rio Preto, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Physical Review E; v. 101, n. 5 MAY 8 2020.
Web of Science Citations: 0

Classical Poisson-Boltzmann theory represents a mean-field description of the electric double layer in the presence of only Coulomb interactions. However, aqueous solvents hydrate ions, which gives rise to additional hydration-mediated ion-ion interactions. Experimental and computational studies suggest damped oscillations to be a characteristic feature of these hydration-mediated interactions. We have therefore incorporated oscillating Yukawa potentials into the mean-field description of the electric double layer. This is accomplished by allowing the decay length of the Yukawa potential to be complex valued. Ion specificity emerges from assigning individual strengths and phases to the Yukawa potential for anion-anion, anion-cation, and cation-cation pairs as well as for anions and cations interacting with an electrode or macroion. Excluded volume interactions between ions are approximated by replacing the ideal gas entropy by that of a lattice gas. We derive mean-field equations for the Coulomb and Yukawa potentials and use their solutions to compute the differential capacitance for an isolated planar electrode and the pressure that acts between two planar, like-charged macroion surfaces. Attractive interactions appear if the surface charge density of the macroions is sufficiently small. (AU)

FAPESP's process: 17/21772-2 - Extensions of the Poisson-Boltzmann Theory to the study of the differential capacitance of an electrical double layer
Grantee:Guilherme Volpe Bossa
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 18/01841-2 - Computational Simulation Studies on the Interaction Between Polyelectrolytes and Macromolecules
Grantee:Sidney Jurado de Carvalho
Support type: Regular Research Grants