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

作者：Fernandez Prini R^*; Laura Japas M; Marceca Ernesto

来源：Journal of Supercritical Fluids, 2010, 55(2): 472-478.

DOI：10.1016/j.supflu.2010.10.009

• Near-critical solvents
• Krichevskii's function
• Solvation
• Intermolecular interactions
• Critical behaviour

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/dx)V,T supra infinity, 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.

• 出版日期2010-12