Thermal Expansivity of Ternary Liquid Mixtures: Application of Hard-Sphere Models and Flory's Statistical Theory

Abstract

Seven hard-sphere models and Flory's statistical mechanical theory have been applied to evaluate thermal expansion coefficient of ternary liquid systems involving dimethyl sulfoxide with phenol/o-cresol in carbon tetrachloride at 293.15, 303.15 and 313.15 K. The results thus obtained are compared with the experimental values of thermal expansivity. The relative applicability of all these approaches to the present investigation has been checked and discussed. The excess values of thermal expansivity have also been calculated and utilized to study the presence and strength of intermolecular interactions in the ternary liquid systems under investigation.

Densities and Viscosities at 293.15–373.15 K, Speeds of Sound and Bulk Moduli at 293.15–333.15 K, Surface Tensions, and Flash Points of Binary Mixtures of n-Hexadecane and Alkylbenzenes at 0.1 MPa

“…For use in this relationship, a polynomial expression was fit to the density–temperature data with the results given in Table . The thermal expansion coefficients based on these expressions are also given in Table at 293.15 K. The value for n -hexadecane at 298.15 K is 0.897 × 10 –3 K –1 , which falls between the reported values of 0.884 × 10 –3 K –1 and 0.898 × 10 –3 K –1 . , Using these thermal expansion coefficients, the excess molar expansion coefficients were calculated by where ϕ is the volume fraction given by Here α mixture is the thermal expansion coefficient of the mixture; α 1 , V 1 and x 1 are the thermal expansion coefficient, molar volume, and mole fraction of the aromatic compound, and α 1 , V 2 , and x 2 are the thermal expansion coefficient, molar volume, and mole fraction of n -hexadecane. The calculated excess molar expansion coefficients are given in Table .…”

“…Moravkova et al 63 report values of a similar magnitude (∼ −6 × 10 6 K −1 ) for binary mixtures of toluene and isooctane. Awasthti et al 62 report that the small excess molar expansion coefficients for nonpolar mixtures (less than 1% of the actual value) are not significant for thermodynamic considerations. Only the larger values for polar mixtures indicated strong intermolecular interactions.…”

Correlations among Composition, Temperature, and Density, Viscosity, or Derived Thermodynamic Properties of Binary Mixtures of Tri-n-butyl Phosphate withn-Hexane orn-Dodecane

“…Excess thermal expansion coefficient values describe the packing of the molecules and their orientation in the mixtures. The positive values of α m E describe the self-association of molecules in the mixtures, whereas the negative values imply the presence of hydrogen bonds within the molecules of components present in the mixture . The values of α m E for TBP + hexane mixtures are negative.…”

“…Proposed correlations have been compared with the existing ones to prove the superiority in prediction. Excess properties of both mixtures have been discussed in terms of intramolecular and intermolecular interactions of molecules. − …”