Binary fluid mixture confined between macroparticles: surface-induced phase transition and long-range surface forces

A binary fluid mixture of components 1 and 2, which is confined between macroparticles separated by distance L, is analyzed using the RISM theory. Hard-sphere interaction is assumed for all the pairs except for particles of component 1 interacting through attractive potential. Component 2, the minor component, is enriched near each macroparticle. When the concentration of component 2 in the bulk Y-2 is sufficiently high, the following is observed. As L decreases component 2 is further enriched in the confined domain, and at L = L-T the theory exhibits a signal of the surface-induced phase transition. As Y-2 increases L-T becomes larger. (C) 2000 Elsevier Science B.V. All lights reserved.