The excess Helmholtz free energy functional was formulated in terms of a modified fundamental measure theory (MFMT) for short ranged repulsion while a functional Taylor expansion for long ranged attractions. The interaction between fluid molecules and the pore wall was expressed by the 10-4-3 potential. The density profiles and the excess adsorption for Lennard-Jones (LJ) fluid inside slit pores were determined by minimizing the grand potential and the results agreed well with the simulation data. The phase equilibria for LJ fluid confined in slit pores were calculated according to the requirement that temperature, chemical potential and grand potential in both phases should be equal.

Key words: Lennard-Jones fluid, slit pore, phase equilibria, density functional theory