Europhys. Lett.
Volume 63, Number 4, August 2003
Page(s) 616 - 622
Section Interdisciplinary physics and related areas of science and technology
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00557-x
Europhys. Lett., 63 (4) , pp. 616-622 (2003)

Conduction and diffusion in two-dimensional electrolytes

R. R. Netz

Sektion Physik, LMU - Theresienstr. 37, 80333 München, Germany

(Received 5 February 2003; accepted in final form 12 June 2003)

Using Brownian-Dynamics simulations, a two-dimensional mixture of charged soft spheres is considered as a model system for cat-anionic lipid layers in tangential electric fields. Electrophoretic mobilities and diffusion constants are determined for a wide range of densities, electric field and Coulomb coupling strengths; the experimentally discovered violation of the Nernst-Einstein relation is reproduced for elevated densities. At large driving fields, a non-equilibrium transition into a charge-modulated structure (at finite Coulomb interaction between particles) or a macroscopic phase separation (at vanishing Coulomb coupling) is found, which might be experimentally reached with mixtures of rather incompatible cationic and anionic lipids.

82.70.-y - Disperse systems; complex fluids.
87.15.-v - Biomolecules: structure and physical properties.
82.45.-h - Electrochemistry and electrophoresis.

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