From accurate data of activities (a), partial molar volumes (V), and compressibility (K) of binary aqueous mixtures, the so‐called Kirkwood–Buff integrals Gij defined by Gij=∫∞0 [ gij(r) −1] 4πr2 dr=f(a,V,K), (i=1,2; j=1,2), have been calculated in the whole concentration range Fourteen water(1)‐organic cosolvent(2) systems [methanol, ethanol, 1‐propanol, 1‐butanol, 2‐methyl‐2‐propanol, acetonitrile, acetone, dimethylsulfoxide, tetrahydrofuran, piperidine, pyridine, 1,4‐dioxane, 2‐aminoethanol, 2‐(dimethylamino)ethanol] have been studied at 25 °C, and two (methanol and ethanol) also at different temperatures The Gij functions show these features in relation to the molecular structures of component 2: (1) when this component presents a large nonpolar moiety, extrema are exhibited by Gij’s at certain concentrations the more marked the larger the nonpolar portion; (2) when component two is bifunctional, Gij trend is monotonic with concentration; (3) in the temperature range 0–90 °C, G22 increases and G12

Solute–solute interactions in water. II. An analysis through the Kirkwood–Buff integrals for 14 organic solutes

The classical formulation of homogeneous nucleation theory has been tested in the methylcyclohexane‐perfluoromethylcyclohexane liquid‐liquid gap miscibility system. The theory was found to be invalid for temperatures above 35°C. The discrepancy between theory and experiment (critical undercoolings are predicted which are less than those observed) can not be explained by simple modifications of the theory. These results confirm the discrepancy found by Sundquist and Oriani.

Experimental test of classical nucleation theory in a liquid-liquid miscibility gap system

A quality assessment algorithm for vapor−liquid equilibrium (VLE) data has been developed. The proposed algorithm combines four widely used tests of VLE consistency based on the requirements of the Gibbs−Duhem equation, with a check of consistency between the VLE binary data and the pure compound vapor pressures. A VLE data-quality criterion is proposed based on the developed algorithm, and it has been implemented in a software application in support of dynamic data evaluation. VLE predictions (NRTL and UNIFAC) were deployed to detect possible anomalies in the data sets. The proposed algorithm can be applied to VLE data sets with at least three state variables reported (pressure, temperature, plus liquid and/or vapor composition) and is applicable to all nonreacting chemical systems at subcritical conditions. Application of the developed algorithms to identification of erroneous published VLE data sets is demonstrated.

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Quality Assessment Algorithm for Vapor-Liquid Equilibrium Data

Extended UNIQUAC model for thermodynamic modeling of CO2 absorption in aqueous alkanolamine solutions

Thermodynamic properties of aqueous mixtures of hydrophilic compounds 2. Aminoethanol and its methyl derivatives

A method of least squares is described for calculating activity coefficients from results of total vapour pressure measurements.

JA Barker

Papers

Determination of Activity Coefficients from total pressure measurements