Application of the Prigogine-Flory-Patterson theory part I. Mixtures ofn-alkanes with bicyclic compounds,benzene, cyclohexane andn-hexane

The Prigogine-Flory-Patterson theory of liquid mixtures has been applied to the H _m ^E and V _m ^E for binary mixtures of an n-alkane with decalin, bicyclohexyl, tetralin, cyclohexylbenzene, benzene, cyclohexane and n-hexane. Furthermore the Prigogine-Flory theory has been used to predict activity coefficients at infinite dilution from the experimentally determined H _m ^E at 25°C and at finite concentrations for n-hexane and n-heptane with decalin, bicyclohexyl, tetralin and cyclohexylbenzene.     

The thermodynamics of mixing C6 and C7 compounds with a bicyclic compound at infinite dilution

The activity coefficients at infinite dilution have been measured at 25°C for cyclohexane, cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, benzene, n-hexane, 1-hexene, 1-hexyne, n-heptane, 1-heptene and 1-heptyne in decahydronaphthalene, bicyclohexyl, 1,2,3,4-tetrahydronaphthalene and cyclohexylbenzene. These results, together with previously determined H _m ^E and V _m ^E have been used to calculate the partial molar excess thermodynamic properties of mixing at infinite dilution.     

Excess volumes and enthalpies of mixing benzene with various bicyclic compounds

The V _m ^E and H _m ^E for solutions of benzene in decahydronaphthalene, in bicyclohexyl, in cyclohexylbezene and in 1,2,3,4-tetrahydronaphthalene have been measured over the complete composition range at 25°C. The results have been fitted to the Flory theory of liquid mixtures.     

The excess volumes of decahydronaphthalene + cyclopentane, + cyclohexane, + cycloheptane and + cyclooctane at two temperatures

The excess volumes of decahydronaphthalene (decalin) + cyclopentane, + cyclohexane, + cycloheptane and + cyclooctane have been measured over the whole composition range at two temperatures. These measurements show many similarities to the V_m^E results of bicyclohexyl + a cycloalkane and 1,2,3,4-tetrahydronaphthalene (tetralin) + a cycloalkane.     

Application of the Prigogine-Flory-Patterson theory part III. Mixtures of a bicyclic compound,benzene, cyclohexane,n-hexane with a cycloalkane,cyclohexene, a cycloalkadiene and benzene

The Prigogine-Flory-Patterson theory of liquid mixtures has been qpplied to the H _m ^E and V _m ^E for binary mixtures of a bicyclic compound, benzene, cyclohexane and n-hexane with a cycloalkane, cyclohexene, a cycloalkadiene and benzene. Furthermore the Prigogine-Flory theory has been used to predict activity coefficients at infinite dilution from the experimentally determined H _m ^E at 25°C for the mixtures cyclohexane, cyclohexene, 1,3-cyclohexadiene, 1,4-cyclohexadiene and benzene with a bicyclic compound. The predictions are compared to experimental results.     

Heats of mixing of 2,2-dimethoxypropane and diethoxymethane with some 1-alkenes

The excess enthalpies of 2,2-dimethoxypropane + 1-hexene, + 1-heptene and + 1-octene, and of diethoxymethane + 1-hexene + 1-octene have been measured at 298.15 K. The values of H^E for all the systems are positive and increase with increasing chain length of the alkene. The results are analysed in term of the quasi-lattice theory of mixtures using the zeroth approximation.     

Excess enthalpies of decahydronaphthalene in cycloalkanes and inn-Alkanes at two temperatures

The H _m ^E of decahydronaphthalene in cyclopentane, cyclohexane, cycloheptane, cyclooctane, n-hexane, n-heptane, n-octane, n-dodecane and in n-hexadecane have been measured over the whole composition range at two temperatures. These results together with previously reported V _m ^E results for the same systems have been fitted to the Flory theory of liquid mixtures.     

Excess molar volumes of 1-nonanol withn-heptane at 25, 35 and 45°C1

The excess molar volumes V _m ^E at atmospheric pressure and at 25, 35 and 45°C for binary mixtures of 1-nonanol, with n-heptane have been obtained over the whole mole fraction range from densities measured with a vibrating-tube densimeter. The measurements at 25°C were extended to high dilution of 1-nonanol. The V _m ^E are sigmoid for the three temperatures, with a small maximum at low mole fractions of the alkanol. The absolute values of V _m ^E increase with temperature from 25 to 45°C.Communicated in part at the 4^th International Conference on Thermodynamics of Solution of Non-Electrolytes, Santiago de Compostela, Spain (1989).     

Activity coefficients of hydrocarbon solutes at infinite dilution in the ionic liquid, 1-methyl-3-octyl-imidazolium chloride from gas–liquid chromatography

Activity coefficients for hydrocarbon solutes at infinite dilution in 1-methyl-3-octyl-imidazolium chloride have been measured using the medium pressure gas–liquid chromatography method. The hydrocarbon solutes used were n-pentane, n-hexane, n-heptane, n-octane, 1-hexene, 1-heptene, 1-octene, 1-hexyne, 1-heptyne, 1-octyne, cyclopentane, cyclohexane, cycloheptane, benzene, and toluene. Activity coefficients at infinite dilution were determined at the following three temperatures (298.15, 308.15, and 318.15) K. Selectivities for benzene and the hydrocarbons are presented and the results indicate that 1-methyl-3-octyl-imidazolium chloride is a reasonable solvent for the separation of an alkane or an alkene from benzene.     

Excess enthalpies of mixing tetrahydrofuran and tetrahydropyran with some chloroalkanes at 26.9°C

Excess enthalpies of mixing H _m ^E of tetrahydrofuran and tetrahydropyran with trichloromethane, tetrachloromethane, 1,2-dichloroethane, 1,1,2-trichloroethane and 1,1,2,2-tetrachloroethane have been determined at 26.9°C and are found to be negative over the entire composition range for both sets of the ether mixtures. H _m ^E decreases in the sequence; dichloroethane > tetrachloromethane > trichloroethane > trichloromethane > tetrachloroethane. The results are explained on the basis of strong O...H-C and weak Cl...O specific interactions. Flory's theory has been used to correlate the experimental data with good agreement found between the theoretical and experimental values of H _m ^E .     

Thermodynamics of Mixtures with Strongly Negative Deviations from Raoult's Law. VII. Excess Molar Volumes at 25°C for 1-Alkanol + N-Methylbutylamine Systems—Characterization in Terms of the ERAS Model

Excess molar volumes, V ^E _m, at 25^°C and atmospheric pressure, over the entire composition range for binary mixtures of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol with-methylbutylamine are reported. They are calculated from densities measured with a vibrating-tube densimeter. All the excess volumes are large and negative over the entire composition range. This indicates strong interactions between unlike molecules, which are greatest for the system involving methanol, characterized by the most negative V ^E _m. For the other solutions, V ^E _m at equimolar composition, is approximately the same. The V ^E _m curves vs. mole fraction are nearly symmetrical. The ERAS model is applied to 1-alkanol + N-methylbutylamine, and 1-alkanol + diethylamine systems. The ERAS parameters confirm that the strongest interactions between unlike molecules are encountered in solutions with methanol. The model consistently describes V ^E _m and excess molar enthalpies H ^E _m of the mixtures studied.     

A Study of Excess Molar Enthalpies and Excess Molar Volumes of Binary Mixtures of 1-Chloropentane + 1-Alkanol (from 1-Butanol to 1-Octanol) at 25°C.

Excess molar enthalpies H ^E _mand excess molar volumes V ^E _m at 25°Cand normal atmospheric pressure for the binary mixtures 1-chloropentane + 1-alkanol(from 1-butanol to 1-octanol) have been determined using a Calvet microcalorimeterand from density measurements using a vibrating tube densimeter. The H ^E _m valuesfor all the mixtures are positive and V ^E _m values are positive or negative dependingon the mole fraction of the chloroalkane. Experimental H ^E _m results are comparedwith the predictions of UNIFAC group-contribution models proposed by Dang andTassios and by Larsen et al., and are discussed in terms of molecular interactions.     

Excess Molar Volumes of Binary Mixtures of 1-Heptanol or 1-Nonanol with n-Polyethers at 25°C

Excess molar volumes V ^E _m at 25°C and atmospheric pressure over the entirecomposition range for binary mixtures of 1-heptanol with 2,5-dioxahexane, 2,5,8-trioxanonane,5,8,11-trioxapentadecane, 2,5,8,11-tetraoxadodecane,or 2,5,8,11,14-pentaoxapentadecane, and mixtures of 1-nonanol with 2,5-dioxahexane,3,6-dioxaoctane, 2,5,8-trioxanonane, 3,6,9-trioxaundecane, 5,8,11-trioxapentadecane,2,5,8,11-tetraoxadodecane, or 2,5,8,11,14-pentaoxapentadecane are reportedfrom densities measured with a vibrating-tube densimeter.V ^E _m curves are nearlysymmetrical at about 0.5 mole fraction. Excess molar volumes are usually positive,indicating predominance of positive contributions to V ^E _m from the disruption ofH bonds of alcohols and from physical interactions. When chain lengths ofboth components of the mixture are increased, the contribution from interstitialaccommodation appears to be sufficiently negative, such that V ^E _m becomes negative(e.g., l-nonanol + 5,8,11-tetraoxapentadecane).     

Volumetric and Transport Properties of Ternary Mixtures Containing 1-Butanol or 1-Pentanol,Triethylamine and Cyclohexane at 303.15 K: Experimental Data,Correlation and Prediction by the ERAS Model

The excess molar volumes, V _m^E, viscosity deviations, Δη, and excess Gibbs energies of activation, ΔG ^*E, of viscous flow have been investigated from density and viscosity measurements for two ternary mixtures, 1-butanol + triethylamine + cyclohexane and 1-pentanol + triethylamine + cyclohexane, and corresponding binaries at 303.15 K and atmospheric pressure over the entire range of composition. The empirical equations due to Redlich-Kister, Kohler, Rastogi et al., Jacob-Fitzner, Tsao-Smith, Lark et al., Heric-Brewer, and Singh et al. have been employed to correlate V _m^E, Δη and ΔG ^*E of the ternary mixtures with their corresponding binary parameters. The results are discussed in terms of the molecular interactions between the components of the mixture. Further, the Extended Real Associated Solution, ERAS, model has been applied to V _m^E for the present binary and ternary mixtures, and the results are compared with experimental data.     

Experimental Study of the Excess Molar Enthalpy of Ternary Mixtures Containing Water + (1,2-Propanediol, or 1,3-Propanediol, or 1,2-Butanediol, or 1,3-Butanediol, or 1,4-Butanediol, or 2,3-Butanediol)+Electrolytes at 298.15 K and Atmospheric Pressure

Excess molar enthalpies (H _m ^E) of ternary mixtures containing water+(1,2-propanediol or 1,3-propanediol or 1,2-butanediol or 1,3-butanediol or 1,4-butanediol or 2,3-butanediol)+(sodium bromide, or ammonium bromide, or tetraethyl ammonium bromide, or 1-n-butyl-3-methylimidazolium bromide at 0.1 mol⋅dm⁻³) at 298.15 K and atmospheric pressure have been determined as a function of composition using a modified 1455 Parr mixture calorimeter. The H _m ^E values are negative for all mixtures over the whole composition range. The influence of the electrolyte on the hydrophobic and hydrophilic effects as well as on the behavior of H _m ^E is discussed.     

Excess Molar Volumes and Excess Logarithm Viscosities for Binary Mixtures of the Ionic Liquid 1-Butyl-3-methylimidazolium Hexaflurophosphate with Some Organic Compounds

Experimental data of densities and viscosities are presented for the mixtures of the ionic liquid 1-butyl-3-methylimidazolium hexaflurophosphate, [C₄mim][PF₆], with acetone, 2-butanone, 3-pentanone, cyclopentanone and ethyl acetate at 298.15 K. Based on these data, excess molar volumes, V_m^E, and excess logarithm viscosities, (lnη)^E, have been determined for the binaries. It is shown that all values of V_m^E are negative but those of (lnη)^E are positive. Interestingly, a minimum in V_m^E and a maximum in (lnη)^E are observed at about the same mole fraction of the ionic liquid (x = 0.3) for every mixture investigated. Combined with the V_m^E data reported in literature, the effects of the [PF₆]⁻ and [BF₄]⁻ anions are compared. The results have been discussed in terms of the ion–dipole interactions of the cations of the ionic liquids with the organic compounds as well as their influence on the association of [C₄mim]⁺ and [PF₆]⁻ in the ionic liquid.     

Excess Molar Enthalpies and Excess Molar Volumes of Binary Mixtures of Benzene and Alkanols with Quinoline

Molar excess enthalpies H _m ^E have been determined over the whole composition range for mixtures of benzene, methanol, ethanol, 1-propanol, 2-propanol and 1-butanol with quinoline at 298.15 K using a Thermometric flow calorimeter. The results reflect a strong H-bond association between an alkanol and quinoline which decreases with increasing length of the alkanol chain. The small H _m ^E for (benzene+quinoline) reflects the similarity of the two molecules. This revised version was published online in August 2006 with corrections to the Cover Date.     

Volumetric and optical study of molecular association in binary mixtures of dimethyl sulphoxide with carboxylic acid

Density and refractive index have been measured for the binary mixture of dimethyl sulphoxide (DMSO) with propanoic acid and n-butyric acid at three temperatures, 293, 303 and 313 K, over the entire composition range. Excess parameters such as excess molar volume (V ^E) and molar refraction deviation (ΔR _m) have been calculated from the measured density and refractive index to study the molecular association between the component molecules. The V ^E and ΔR _m values of these mixtures were fitted to the Redlich–Kister polynomial equation. Both excess parameters were plotted against the mole fraction of DMSO over the whole composition range. The values of V ^E and ΔR _m have been found to be negative for both mixtures over the entire composition range, which suggests the presence of strong intermolecular interaction. The experimental refractive data of these mixtures were also used to test the validity of the empirical relations for the refractive index.     

Excess Molar Volumes and Excess Partial Molar Volumes of Triethylene Glycol Monoethyl Ether–n-Alcohol Mixtures at 25°C

We have measured excess molar volumes V^E _m of binary mixtures of triethylene glycol monoethyl ether with methanol, ethanol, 1-propanol, 1-pentanol, and 1-hexanol over the full range of compositions at 25°C. The measurements were carried out with a continuous-dilution dilatometer. The excess molar volumes V^E _m are negative over the entire range of composition for the systems triethylene glycol monoethyl ether + methanol, + ethanol, and + 1-propanol and positive for the remaining systems, triethylene glycol monoethyl ether + 1-pentanol, and + 1-hexanol. The excess V^E _m increases in the positive direction with increasing chain length of the n-alcohol. The measured excess volumes have been compared to our previous published data with an effort to assess the effects of replacing methyl by ethyl groups and of inserting oxyethylene groups. The results have been used to estimate the excess partial molar volumes V^E _m,i of the components. The behavior of V^E _m and V^E _m,i with composition and the number of carbon atoms in the alcohol molecule is discussed.     

Densities and Volumetric Properties of Binary Mixtures of Formamide with 1-Butanol, 2-Butanol, 1,3-Butanediol and 1,4-Butanediol at Temperatures between 293.15 and 318.15 K

The densities of binary mixtures of formamide (FA) with 1-butanol, 2-butanol, 1,3-butanediol, and 1,4-butanediol, including those of the pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. From the experimental data, the excess molar volume, V _m ^E, partial molar volumes, and , at infinite dilution, and excess partial molar volumes, and , at infinite dilution were calculated. The variation of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions in these mixtures. The partial molar expansivities, and , at infinite dilution and excess partial molar expansivities, and , at infinite dilution were also calculated. The V _m ^E values were found to be positive for all the mixtures at each temperature studied, except for FA + 1-butanol which exhibits a sigmoid trend wherein V _m ^E values change sign from positive to negative as the concentration of FA in the mixture is increased. The V _m ^E values for these mixtures follow the order: 1-butanol < 2-butanol < 1,3-butanediol < 1,4-butanediol. It is observed that the V _m ^E values depend upon the number and position of hydroxyl groups in these alkanol molecules.