Europhys. Lett.
Volume 73, Number 6, March 2006
Page(s) 864 - 870
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 February 2006
Europhys. Lett., 73 (6), pp. 864-870 (2006)
DOI: 10.1209/epl/i2005-10468-4

Localisation-delocalisation transition of electrolytes between micro-electrodes

A. Esztermann, R. Messina and H. Löwen

Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf Universitätsstraße 1, D-40225 Düsseldorf, Germany

received 20 October 2005; accepted in final form 17 January 2006
published online 1 February 2006

Employing computer simulations and Poisson-Boltzmann theory, we show that a symmetric electrolyte in an electric condenser undergoes a localisation-delocalisation transition as a function of the external voltage U. The transition occurs at the critical voltage $U_\text{c}$ corresponding to the situation where the surface charge density of the plates equals the area charge density of completely charge-separated electrolytes. The average distance of the electrolyte ions to the plates diverges logarithmically for $U \searrow U_\text{c}$. This transition is expected to be observable in micro-electrodes.

61.20.Qg - Structure of associated liquids: electrolytes, molten salts, etc.
61.20.Ja - Computer simulation of liquid structure.
82.70.Dd - Colloids.

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