Abstract
We investigate the fluid-fluid demixing phase transition of the Asakura-Oosawa model colloid-polymer mixture confined between two smooth parallel hard walls using density functional theory and computer simulations. Comparing fluid density profiles for statepoints away from colloidal gas-liquid coexistence yields good agreement of the theoretical results with simulation data. Theoretical and simulation results predict consistently a shift of the demixing binodal and the critical point towards higher polymer reservoir packing fraction and towards higher colloid fugacities upon decreasing the plate separation distance. This implies capillary condensation of the colloid liquid phase, which should be experimentally observable inside slitlike micropores in contact with a bulk colloidal gas.