Liquid–liquid immiscibility loops predicted with the simplified-perturbed-hard-chain theory

Abstract

In this study, it will be shown that in binary mixtures, type VI phase behavior, according to the classification of van Konynenburg and Scott [Philos. Trans. R. Soc. London, Ser. A 298, 495 (1980)], can be obtained from a simple, semitheoretical equation of state. The applied equation of state was derived from the simplified-perturbed-hard-chain theory (SPHCT). In literature, there are no known examples of type VI phase behavior being obtained from a simple equation of state. In addition, the systematic changes in phase behavior from type I via type V towards type VI will be discussed in this contribution. Surprisingly, a new type of phase behavior was found that was foreseen by Schneider [Ber. Bunsenges. Phys. Chem. 70, 497 (1966)]. It is proposed to call this new phase behavior type VIII.