Near-critical and supercritical dilute solutions viewed from macroscopic and molecular-scale perspectives

R FERNANDEZ PRINI; M. LAURA JAPAS; ERNESTO MARCECA

JOURNAL OF SUPERCRITICAL FLUIDS

ELSEVIER SCIENCE BV

Lugar: Amsaterdam; Año: 2010 vol. 55 p. 472 - 478

0896-8446

Partial molar properties of dilute solutes in near-critical solvents exhibit a strong dependence on temperatureand density which hinders the description of their behaviour under those conditions. We usedthe well-behaved Krichevskii function, J = (dp/dx)V,T supra infinity, to describe that region of the thermodynamicspace, and have extended its use to ternary solutions (two solutes + one near-critical solvent)successfully. The use of supercritical solvents permits a controlled and continuous exploration of thedensity dependence of solutes’ properties without undergoing phase transitions, hence the availabilityof a non-diverging property like J to describe the systems is greatly important.Weshow its application forbinary and ternary systems that have been studied and also give some information about the molecularstructure of near-critical solutions. This knowledge provides a better understanding about solvation andits dependence on long-range (critical) fluctuations in the presence of intermolecular interactions.