Demixing and the force between parallel plates immersed in binary liquid mixtures

Grand Canonical Monte Carlo calculations are used to examine the phase behavior of model binary liquid mixtures confined between parallel plates. The stable and metastable states are identified by direct evaluation of the grand potential. It is shown that demixing transitions can lead to long-range attractive forces acting between the plates, verifying earlier predictions based on approximate integral equation theories. The nature of these transitions and the physical origin of the accompanying attractive forces are discussed. (C) 2001 American Institute of Physics.