A modified perturbed hard-sphere-chain equation of state: consideration of attractive contribution Original Research Article

We adapted a new perturbation term reported by Bokis et al. for the modified perturbed hard-sphere-chain (PHSC) equation of state. The new model better agrees with the simulation data for illustrating both repulsive and attractive contributions than those of the PHSC equation of state. Three characteristic parameters, r, σ, and ε, are obtained from thermodynamic properties of pure saturated species and directly used to calculate coexistence curves of given binary systems. Vapor–liquid equilibria and liquid–liquid equilibria of fluids are remarkably well predicted by the model even in the case of polymer solution that shows non-ideal phase behavior.