The study of uniaxial–biaxial phase transition of confined hard ellipsoids using density functional theory

Abstract

The density profiles and corresponding order parameters of the hard ellipsoids confined between two hard walls and also in contact with a single hard wall are studied using the density functional theory (DFT). The hypernetted-chain (HNC) approximation is used to write excess grand potential of the system with respect to the bulk value. To simplify the calculations, we use restricted orientation model (ROM) for the orientation of ellipsoids to find the density profiles and order parameters. DFT shows that there is a uniaxial–biaxial (U–B) phase transition near a single hard wall and also between two hard walls for a fluid consisting of uniaxial hard ellipsoidal particles with finite elongation.