abstract
The thermodynamics of asymmetric liquid-liquid criticality is updated by incorporating pressure effects into the complete-scaling formulation earlier developed for incompressible liquid mixtures [C. A. Cerdeirin approximate to a , Chem. Phys. Lett. 424, 414 (2006); J. T. Wang , Phys. Rev. E 77, 031127 (2008)]. Specifically, we show that pressure mixing enters into weakly compressible liquid mixtures as a consequence of the pressure dependence of the critical parameters. The theory is used to analyze experimental coexistence-curve data in the mole fraction-temperature, density-temperature, and partial density-temperature planes for a large number of binary liquid mixtures. It is shown how the asymmetry coefficients in the scaling fields are related to the difference in molecular volumes of the two liquid components. The work resolves the question of the so-called "best order parameter" discussed in the literature during the past decades.
keywords
COEXISTENCE-CURVE DIAMETERS; CRITICAL REGION; CRITICAL-POINT; LIGHT-SCATTERING; THERMODYNAMIC PROPERTIES; DIMETHYL CARBONATE; PHASE-EQUILIBRIA; BINARY-SYSTEMS; TURBIDITY; FLUIDS
subject category
Chemistry; Physics
authors
Perez-Sanchez, G; Losada-Perez, P; Cerdeirina, CA; Sengers, JV; Anisimov, MA
our authors
Germán Pérez-Sánchez
Junior Researcheracknowledgements
Financial support from the "Xunta de Galicia" under Grant No. PGIDIT-06PXIB3832828PR has been greatly appreciated. The research of G.P.-S. and of P.L.-P. was supported by the "Ministerio de Educacion y Ciencia" of Spain under the "Programa Nacional de Formacion del Profesorado Universitario" (Grant Nos. AP-2005-1959 and AP-2004-2947).