title: Capillary bridging and long-range attractive forces in a mean-field approach.
abstract: When a mixture is confined, one of the phases can condense out. This condensate, which is otherwise metastable in the bulk, is stabilized by the presence of surfaces. In a sphere-plane geometry, routinely used in atomic force microscope and surface force apparatus, it can form a bridge connecting the surfaces. The pressure drop in the bridge gives rise to additional long-range attractive forces between them. By minimizing the free energy of a binary mixture we obtain the force-distance curves as well as the structural phase diagram of the configuration with the bridge. Numerical results predict a discontinuous transition between the states with and without the bridge and linear force-distance curves with hysteresis. We also show that similar phenomenon can be observed in a number of different systems, e.g., liquid crystals and polymer mixtures.
authors.affiliation: Max-Planck-Institut fur Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Andrienko
authors.forename: P
authors.initials: P
authors.lastname: Patricio
authors.forename: O I
authors.initials: OI
authors.lastname: Vinogradova