Phase equilibria in binary mixtures. Part 2.—Miscibility gap with two critical temperatures (closed-loop phase diagram)

Abstract

The model outlined in the preceding paper is applied to binary mixtures which feature a miscibility gap with two critical temperatures. By simple modification of the mathematical expressions for the order parameter and the rectilinear diameter, the model accurately describes equilibria between the coexisting phases over the whole range of coexistence. The model has been applied to the following binary systems: tetrahydrofuran + heavy water, 2,6-lutidine + water, s-benzylethylamine + glycerol and bismuth + bismuth trichloride.