title: Interaction regimes for oppositely charged plates with multivalent counterions.
abstract: Within a mean-field treatment of the interaction between two oppositely charged plates in a salt-free solution, the distance at which a transition from an attractive to a repulsive regime appears can be computed analytically. The mean-field description, however, breaks down under strong Coulombic couplings, which can be achieved at room temperature with multivalent counterions and highly charged surfaces. Making use of the contact theorem and simple physical arguments, we propose explicit expressions for the equation of state in several situations at short distances. The possibility of Bjerrum pair formation is addressed and is shown to have profound consequences on the interactions. To complete the picture, we consider the large-distance limit, from which schematic phase diagram discriminating attractive from repulsive regions can be proposed.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: Fabien
authors.initials: F
authors.lastname: Paillusson
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Trizac
mesh_terms: D000465:Algorithms; D001703:Biophysics / Q000379:methods*; D003102:Colloids / Q000737:chemistry*; D007477:Ions; D015233:Models, Statistical; D008962:Models, Theoretical; D009995:Osmosis; D010316:Particle Size; D016012:Poisson Distribution; D011312:Pressure; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003102:Colloids; D007477:Ions; D012997:Solvents