Europhys. Lett.
Volume 70, Number 3, May 2005
Page(s) 341 - 347
Section Condensed matter: structural, mechanical and thermal properties
Published online 13 April 2005
Europhys. Lett., 70 (3), pp. 341-347 (2005)
DOI: 10.1209/epl/i2004-10500-3

Counterions at disordered charged planar surfaces

C. C. Fleck1 and R. R. Netz2

1  Fachbereich Physik, Universität Konstanz Universitätsstr. 10, 78457 Konstanz, Germany
2  Physik Department, TU Munich - 85748 Garching, Germany

received 16 December 2004; accepted in final form 15 March 2005
published online 13 April 2005

Using field-theoretic and numerical methods, we study counterion density profiles at planar surfaces with disordered surface-charge distributions. Experimental examples include mixed lipid bilayers and weakly charged surfaces where pH-controlled charge regulation takes place. Quenched as well as annealed disordered surface charge distributions exhibit markedly enhanced counterion densities close to the surface even for weak coupling parameter, in contrast to ordered dilute substrates where the counterion surface enhancement is relatively weak.

61.20.Qg - Structure of associated liquids: electrolytes, molten salts, etc.
87.16.Dg - Membranes, bilayers, and vesicles.
87.15.Aa - Theory and modeling; computer simulation.

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