The phase behaviors of two-site associating Lennard-Jones(LJ) fluid confined in slit pores were investigated by using the modified fundamental measure theory (MFMT) and density functional theory (DFT). The phase equilibria were determined according to the requirement that temperature, chemical potential and grand potential in both phases should be equal. The influences of association energy and pore width on the thermodynamic properties including equilibrium density distributions of molecules and monomers, adsorption and desorption isotherms, and vapor-liquid coexistence were demonstrated.

Key words: two-site associating Lennard-Jones fluid, slit pore, phase behavior, density functional theory