Models of liquid mixtures : Structure , dynamics , and properties *

Models of the structure and properties of liquid mixtures are outlined. The main focus is on quasichemical models for the modeling of supramolecular ordering in mixtures, self-organized by H-bonds, leading to a unified description of their physicochemical properties. Models of polyvariable supramolecular species are discussed with respect to structure and composition of the mixtures, taking into account the cooperativity of H-bonding, and leading to a description of electric (dipole moment) and optic (polarizability) properties. We analyze the interrelations of thermodynamic functions (Gibbs energy, enthalpy, entropy), dielectric (permittivity) and optical properties (refractive index and its fluctuation derivatives, defining Rayleigh light scattering) of nonideal mixtures as well as the microscopic characteristics of the aggregates. Methods are developed in order to obtain both integral and differential parameters of aggregation. Models for the description of supramolecular reorganization, intramolecular transitions, and energy transfer during molecular thermal motion as well as fluctuation and relaxation phenomena are considered. Applications both to liquids and mixtures are outlined. The supramolecular assemblies in liquids with long-range molecular correlations are established. Macroscopic manifestations of the supramolecular organization in the properties of liquids are characterized.