Can the Boyle's and critical parameters be unambiguously correlated for polar and associating fluids, liquid metals, ionic liquids?

Abstract

An independent test of thermodynamic consistency applied to a presently widespread methodology of Zeno-line (ZL) has demonstrated its restricted predictive abilities. Unfortunately, a subjective choice of the reference Boyle (B) parameters for the reduced critical temperature Tc/TB and the critical density ρc/ρB as well as the imposed empirical linear constraints on their presumably universal correlation can lead to unadjusted predictions of critical properties for liquid metals, polar and associating fluids, water and many other complicated substances. To study such “difficult” compounds the alternative universal set of correlations between the critical compressibility factor Zc, the Riedel's factor of similarity Ac and both B-parameters ρB,TB is introduced. It follows from the model of fluctuational thermodynamics (FT) and the principle of global fluid asymmetry (GFA) formulated recently as its consequence. This new FT-methodology describes a set of known B-temperatures with an excellent accuracy while the respective B-densities are fixed by the empirical Timmermans correlation. We believe that critical properties for the afore-mentioned “difficult” fluids can be reasonably represented and/or predicted by the proposed universal FT-methodology. The revealed interrelation between the effective potential parameters established in terms of the actual critical properties forces us to disavow the tentative supposition about the violation of PCS (principle of corresponding states) in complex liquids.