Scaled hard-sphere equations of state for linear fused hard-sphere pure fluids and fluid mixtures

Abstract

The performance of a theoretically based equation of state, previously developed for hard molecular fluids, is analysed on the basis of computer-simulation data which have recently become available for fluids of linear fused hard-sphere molecules with up to eight monomers. The equation allows one to obtain the excess compressibility factor of hard-body fluids by scaling the excess compressibility factor of an equivalent hard-sphere fluid by means of a parameter which can be obtained from the geometry of the molecules. The agreement between theory and simulation was found to be excellent. The extension of the equation of state to fluid mixtures of hard molecules expresses the excess compressibility factor of the mixture as a scaling of the excess compressibility factor of an equivalent hard-sphere fluid mixture. The scaling parameter is again obtained from the geometry of the molecules involved in the mixture. The equation of state obtained in this way is compared with NPT Monte Carlo simulations for several fluid mixtures of linear fused hard-sphere molecules which are also reported.