INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
Near-critical and supercritical dilute solutions viewed from macroscopic and molecular-scale perspectives
R. FERNÁNDEZ PRINI; M. L. JAPAS; E. MARCECA
JOURNAL OF SUPERCRITICAL FLUIDS
ELSEVIER SCIENCE BV
Año: 2010 vol. 55 p. 472 - 472
Partial molar properties of dilute solutes in near-critical solvents exhibit a strong dependence on temperature and density which hinders the description of their behaviour under those conditions. We used the well-behaved Krichevskii function, J = (dp / dx2)V,T, to describe that region of the thermodynamic space, 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 the density dependence of solutes properties without undergoing phase transitions, hence the availability of a non-diverging property like J to describe the systems is greatly important. We show its application for binary and ternary systems that have been studied and also give some information about the molecular structure of near-critical solutions. This knowledge provides a better understanding about solvation and its dependence on long-range (critical) fluctuations in the presence of intermolecular interactions.