Ions and dipoles in electric field: nonlinear polarization and field-dependent chemical reaction.

Autor: Onuki A; Department of Physics, Kyoto University, Kyoto, 606-8502, Japan. onuki@scphys.kyoto-u.ac.jp.
Jazyk: angličtina
Zdroj: The European physical journal. E, Soft matter [Eur Phys J E Soft Matter] 2024 Jan 11; Vol. 47 (1), pp. 3. Date of Electronic Publication: 2024 Jan 11.
DOI: 10.1140/epje/s10189-023-00398-0
Abstrakt: We investigate electric-field effects in dilute electrolytes with nonlinear polarization. As a first example of such systems, we add a dipolar component with a relatively large dipole moment [Formula: see text] to an aqueous electrolyte. As a second example, the solvent itself exhibits nonlinear polarization near charged objects. For such systems, we present a Ginzburg-Landau free energy and introduce field-dependent chemical potentials, entropy density, and stress tensor, which satisfy general thermodynamic relations. In the first example, the dipoles accumulate in high-field regions, as predicted by Abrashikin et al.[Phys.Rev.Lett. 99, 077801 (2007)]. Finally, we consider the case, where Bjerrum ion pairs form a dipolar component with nonlinear polarization. The Bjerrum dipoles accumulate in high-field regions, while field-induced dissociation was predicted by Onsager [J. Chem. Phys.2, 599 (1934)]. We present an expression for the field-dependent association constant K(E), which depends on the field strength nonmonotonically.
(© 2024. The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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