Vapor–liquid phase diagrams and structure of a square-well fluid confined in weakly attractive cylindrical pores

Using canonical Monte Carlo simulations, the vapor-liquid phase diagrams of a square-well fluid confined in hard and weakly attractive cylindrical pores are calculated. The critical temperature shows a maximum as a function of the attraction strength between the fluid particle and the pore wall. This maximum is located where the fluid–fluid equals the wall–fluid interaction strengths. With the aid of combined density profiles in the axial and radial directions the maximum of the critical temperature is correlated with the structure of the confined fluid.

► The VL equilibrium diagrams of a square-well fluid confined in cylindrical pores are calculated by MC simulation.
► The non-monotonic behavior of the critical temperature is discussed in terms of the confined fluid structure.
► The fluid structure is determined with a joint view of the density profiles in the axial and radial directions of the pore.
► A change of the shape of the VL interface is observed as the pore wall becomes more attractive.