8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Thu 811:10-14:00P7.73Critical Casimir forces in many-body systemsThiago Mattos, 1 Ludger Harnau, 1 and Siegfried Dietrich 11 Max-Planck-Institut for Intelligent Systems, Hauptstrasse 52, 70563, Stuttgart,GermanyThe confinement of a binary liquid mixture close to its critical (demixing) point leads to effectivecritical Casimir forces between the confining boundaries. These long-ranged forces can be eitherattractive or repulsive depending on the choice of the boundary conditions, i. e. the preference ofthe confining surfaces in adsorbing one of the two components of the liquid mixture. We investigatethe effect of many-body interactions in the Casimir force, which is expected to be non-additive,for two spherical colloids close to a wall immersed in a binary liquid mixture close to criticality.We calculate this force for three different systems: (i) single spherical colloid close to a wall, (ii)two spherical colloids and (iii) two spherical colloids close to a wall. For all systems we considerseveral combinations of boundary conditions for the colloids and for the wall.73