THERMOPHYSICAL AND THERMODYNAMIC BEHAVIOR OF BINARY LIQUID MIXTURES: A CRITICAL REVIEW OF MOLECULAR INTERACTIONS, EXCESS PROPERTIES, AND CORRELATION MODELS

Abstract

The thermodynamic characteristics of two-liquid mixtures are strongly influenced by factors including molecular dispersion forces, polarity, hydrogen bonding, and differences in molecular size and shape between the mixture components․ Ultrasonic velocity, refractive index, and calculated thermodynamic properties such as excess Gibbs free energy, viscosity, Molar volume calculations have also been carried out for these systems. This article reviews information about the thermodynamic properties of liquid mixtures and their relationship to molecular interactions in the mixtures․ The types of binary liquid mixtures discussed include ester-alcohol‚ amine-alcohol‚ and hydrocarbon alcohol mixtures and others․ Thermodynamic data on these and other binary liquid mixtures obtained at various compositions and temperatures are reviewed․ Other topics include the effects of chain length and temperature and other structural features on the physical properties of liquid mixtures and the effects of structural and polar differences on excess molar volume and viscosity of liquid mixtures․ Mathematical methods for modeling thermodynamic nonequilibrium behavior of liquid mixtures‚ including the Redlich-Kister equation and various activity coefficient correlations‚ are discussed․ No one method or data set can fully describe the molecular interactions that occur in liquid mixtures․ Combining thermodynamic data with other types of data can provide more information about thermodynamic nonequilibrium behavior of liquid mixtures․ Recommendations for future research include efforts to develop improved predictive methods and gather additional thermodynamic information on liquid mixtures to help predict the properties of other complex liquid mixtures․