Colloid-polymer mixtures between asymmetric walls: Evidence for an interface localization transitionA. De Virgiliis1, R. L. C. Vink1, 2, J. Horbach1 and K. Binder1
1 Institut für Physik, Johannes-Gutenberg-Universität Mainz - Staudinger Weg 7, 55099 Mainz, Germany
2 Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf - Universitätsstr. 1, 40225 Düsseldorf, Germany
received 13 September 2006; accepted in final form 26 January 2007; published March 2007
published online 28 February 2007
We demonstrate via computer simulation that mixtures of colloids and polymers confined to thin films have the ability to undergo an interface localization transition. While one wall of the film is assumed to be hard for both particles, at the other wall, an additional repulsive potential acts, but on the colloids only. By varying the strength of this repulsion, a crossover from capillary condensation to interface localization is found. The latter occurs under conditions where in the bulk almost complete phase separation has occurred.
05.70.Jk - Critical point phenomena.
64.60.Fr - Equilibrium properties near critical points, critical exponents.
68.08.Bc - Wetting.
© Europhysics Letters Association 2007