Prediction of density of liquid mixtures using Flory's statistical theory†

Estimation of Ultrasonic Velocity, Density, Internal Pressure, and Thermophysical Parameters of Ionic Liquid Mixtures: Application of Flory's Statistical Theory

Flory's statistical theory (FST) has been employed to estimate the ultrasonic velocity, density, internal pressure, and several important thermophysical parameters such as the energy of vaporization, the heat of vaporization, cohesive energy density, polarity index, and solubility for eight binary mixtures of ionic liquids and water within the temperature range of 288.15 to 308.15 K. The ionic liquids chosen for this investigation are [BMim][dca], [BMim][TfO], [BMpy][TfO], [BMpyr][dca], [BMpyr][TfO], [EEPy][ESO4], [HMim][dca], and [MPy][MSO4]. The predicted values of ultrasonic velocity and density show good agreement with the data reported in the literature. It endorses the applicability of FST to these binary mixtures. A comparative analysis of the internal pressure values (Pi) determined by using FST and the standard thermodynamic approach is also presented. The results obtained for Pi using both approaches show good agreement. Besides, for the mixtures under study, the correlation between ultrasonic velocity, density, and surface tension has also been examined. The variation of thermophysical parameters with concentration and temperature changes has been utilized to explore the nature and strength of the solute-solvent interactions prevalent in these mixtures. It is pointed out that A-A-type interactions dominate over A-B-type interactions in water-rich regions of the mixtures.

Prediction of Internal Pressure of Binary Liquid Mixtures Using Flory's Statistical Theory

Internal pressures of a number of binary liquid mixtures of varying natures of component liquids have been predicted using Flory's statistical theory. The predicted values have been compared with the experimentally calculated ones. Good approximation has been observed.

Application of Flory's Statistical Theory for the Estimation of Internal Pressure of the Liquid Mixtures

Flory's Statistical Theory has been employed for the evaluation of internal pressure of liquid mixtures at varying conditions. The method used for the evaluation does not use any empirical relation, unlike the approaches of previous workers. The computed values have been compared against the values obtained from thermodynamic relation taken as an experimental method. To the best of our knowledge, the present approach has not been employed previously by any worker. The excellent agreements between the computed and experimental values prove the applicability of this approach for the evaluation of internal pressure in liquid mixtures.