title: Charge fluctuations and counterion condensation.
abstract: We predict a condensation phenomenon in an overall neutral system, consisting of a single charged plate and its oppositely charged counterions. Based on the "two-fluid" model, in which the counterions are divided into a "free" and a "condensed" fraction, we argue that for high surface charge, fluctuations can lead to a phase transition in which a large fraction of counterions is condensed. Furthermore, we show that depending on the valence, the condensation is either a first-order or a smooth transition.
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pensylvania 19104, USA.
authors.forename: A W C
authors.initials: AW
authors.lastname: Lau
authors.forename: D B
authors.initials: DB
authors.lastname: Lukatsky
authors.forename: P
authors.initials: P
authors.lastname: Pincus
authors.forename: S A
authors.initials: SA
authors.lastname: Safran