Isothermal (vapor+liquid) equilibria of four binary mixtures

Abstract: The Kirkwood–Buff integrals and the volume-corrected preferential solvation parameters for the first solvation shell of binary mixtures of tetrahydrofuran with many organic solvents, calculated from reported thermodynamic data at the temperatures for which these data were available, are reported. The co-solvents include c-hexane, methyl-c-hexane, n-heptane, i-octane, benzene, toluene, ethylbenzene, 1-chlorobutane, dichloromethane, 1,2-dichloroethane, chloroform, 1,1,1-trichloroethane, tetrachlorom-ethane, tetrachloroethene, hexafluoro benzene, ethanol, 1-propanol, 2-propanol, dibutyl ether, acetic acid, acetone, dimethyl sulfoxide, tetramethylene sulfone (sulfolane), acetonitrile, pyrrolidine, and triethylamine. The preferential solvation parameters of these mixtures are discussed in terms of the interactions that occur.

Abstract: Literature data on partitioning of compounds from the gas phase to ketones and from water to ketones has been collected and analyzed through the Abraham solvation equations. It is shown that for partition into both dry and wet ketones the main solvent factors that aid partitioning into the ketones are the polarizability/dipolarity, hydrogen-bond basicity and hydrophobicity (size) of the ketones. Reliable equations have been established for partitioning from the gas phase and from water to dry acetone, dry butanone, dry cyclohexanone and to wet methyl isobutyl ketone. It is further shown that partitioning into dry butanone and dry cyclohexanone leads to different equations than partitioning into the wet solvents, and that data on partitioning into the wet and dry ketones cannot be combined.

Abstract: The potential large-scale production of fullerene C60 and its widespread use in consumer products may translate into occupational and public exposure and in long-term environmental exposure. To assess the risk and fate of C60 in the environment, it is important to understand its solvate formation in common industrial solvents as the solvates may affect various properties of C60 including reactivity and toxicity, particularly when solvates occur in C60 clusters. In this study, the solubility measurements in mixed solvent system can provide useful information about solvate formation. The solubility of C60 was measured in pure toluene, tetrahydrofuran, ethanol, and acetonitrile to be 3000, 11, 1.4, and 0.04 mg/L, respectively. Additionally, the solubility of C60 was measured in mixtures of toluene−acetonitrile, toluene−ethanol, toluene−tetrahydrofuran, and acetonitrile−tetrahydrofuran. The solubility data were modeled with some accuracy using Wohl’s equation. The estimated crystal energy term for C60 in tetr...

Abstract: The Kirkwood–Buff integrals and the volume-corrected preferential solvation parameters for the first solvation shell of binary mixtures of tetrahydrofuran with many organic solvents, calculated from reported thermodynamic data at the temperatures for which these data were available, are reported. The co-solvents include c-hexane, methyl-c-hexane, n-heptane, i-octane, benzene, toluene, ethylbenzene, 1-chlorobutane, dichloromethane, 1,2-dichloroethane, chloroform, 1,1,1-trichloroethane, tetrachlorom-ethane, tetrachloroethene, hexafluoro benzene, ethanol, 1-propanol, 2-propanol, dibutyl ether, acetic acid, acetone, dimethyl sulfoxide, tetramethylene sulfone (sulfolane), acetonitrile, pyrrolidine, and triethylamine. The preferential solvation parameters of these mixtures are discussed in terms of the interactions that occur.

Abstract: Data have been compiled from the published literature on the partition coefficients of solutes and vapors into 1,2-dichloroethane from both water and from the gas phase. The logarithms of the water-to-1,2-dichloroethane partition coefficients (log P ) and gas-to-1,2-dichloroethane partition coefficients (log K ) are correlated with the Abraham solvation parameter model. The derived correlations describe the observed log P and log K values to with standard deviations of 0.16 and 0.18 log units, respectively. The predictive abilities of the derived correlations are assessed by dividing the database into a separate training set and test set.

Abstract: Chapter 1: The Estimation of Physical Properties. Chapter 2: Pure Component Constants. Chapter 3: Thermodynamic Properties of Ideal Gases. Chapter 4: Pressure-Volume-Temperature Relationships of Pure Gases and Liquids. Chapter 5: Pressure-Volume-Temperature Relationships of Mixtures. Chapter 6: Thermodynamic Properties of Pure Components and Mixtures. Chapter 7: Vapor Pressures and Enthalpies of Vaporization of Pure Fluids. Chapter 8: Fluid Phase Equilibria in Multicomponent Systems. Chapter 9: Viscosity. Chapter 10: Thermal Conductivity. Chapter 11: Diffusion Coefficients. Chapter 12: Surface Tension.

Abstract: A critical discussion is given of the use of local compositions for representation of excess Gibbs energies of liquid mixtures. A new equation is derived, based on Scott's two-liquid model and on an assumption of nonrandomness similar to that used by Wilson. For the same activity coefficients at infinite dilution, the Gibbs energy of mixing is calculated with the new equation as well as the equations of van Laar, Wilson, and Heil; these four equations give similar results for mixtures of moderate nonideality but they differ appreciably for strongly nonideal systems, especially for those with limited miscibility. The new equation contains a nonrandomness parameter α12 which makes it applicable to a large variety of mixtures. By proper selection of α12, the new equation gives an excellent representation of many types of liquid mixtures while other local composition equations appear to be limited to specific types. Consideration is given to prediction of ternary vapor-liquid and ternary liquid-liquid equilibria based on binary data alone.

Abstract: To obtain a semi-theoretical equation for the excess Gibbs energy of a liquid mixture, Guggenheim's quasi-chemical analysis is generalized through introduction of the local area fraction as the primary concentration variable. The resulting universal quasi-chemical (UNIQUAC) equation uses only two adjustable parameters per binary. Extension to multicomponent systems requires no ternary (or higher) parameters. The UNIQUAC equation gives good representation of both vapor-liquid and liquid-liquid equilibria for binary and multicomponent mixtures containing a variety of nonelectrolyte components such as hydrocarbons, ketones, esters, amines, alcohols, nitriles, etc., and water. When well-defined simplifying assumptions are introduced into the generalized quasi-chemical treatment, the UNIQUAC equation reduces to any one of several well-known equations for the excess Gibbs energy, including the Wilson, Margules, van Laar, and NRTL equations. The effects of molecular size and shape are introduced through structural parameters obtained from pure-component data and through use of Staverman's combinatorial entropy as a boundary condition for athermal mixtures. The UNIQUAC equation, therefore, is applicable also to polymer solutions.

Abstract: A new correlation of second virial coefficients of both polar and nonpolar systems is presented. It uses the Pitzer-Curl correlation for nonpolar compounds, but in a modified form. The second virial coefficient of nonhydrogen bonding compounds (ketones, acetaldehyde, acetonitrile, ethers) and weakly hydrogen bonding compounds (phenol) is fitted satisfactorily with only one additional parameter per compound, which is shown to be a strong function of the reduced dipole moment. Two parameters are needed for hydrogen bonding compounds (alcohols, water), but for alcohols, one parameter has been kept constant and the other expressed as a function of the reduced dipole moment. The extension of the correlation to mixtures is satisfactory, direct, and involves only one coefficient per binary.