VmE Values Research Articles

Density and Viscosity of Ketones with Toluene at Different Temperatures and at Atmospheric Pressure

Densities and viscosities of binary mixtures of toluene with acetone, ethyl methyl ketone, and acetophenone including those of pure liquids are measured over the entire composition range at temperatures (298.15, 303.15, and 308.15) K, respectively, at atmospheric pressure. From these experimental data, the values of excess molar volume VmE and the deviations in viscosity Δη are calculated and fitted to the Redlich−Kister polynomial equation. The variation of these properties shows strong interaction between the molecules of the mixtures.

Density, Viscosity, and Vapor Pressure for Binary Mixtures of Tricyclo [5.2.1.02.6] Decane and Diethyl Carbonate

The density, viscosity, and vapor pressure for binary mixtures of tricyclo [5.2.1.02.6] decane (JP-10), a high-energy density hydrocarbon fuel, with diethyl carbonate are presented. Excess volume, VmE, and viscosity deviation, Δη, for the binary mixtures have been calculated. Positive values of VmE, negative values of Δη, and positive deviations from Raoult’s law for the vapor pressures are observed. The deviation results are discussed in terms of the changes of molecular interactions in the mixtures, and they are fitted with the Redlich−Kister equation. The viscosities have also been correlated with several semiempirical equations. These physical property data and calculations provide valuable information on the development and application of new high-energy density hydrocarbon fuels.

Experimental Thermodynamic Properties of 1-Butyl-2-methylpyridinium Tetrafluoroborate [b2mpy][BF4] with Water and with Alkan-1-ol and Their Interpretation with the COSMO-RS Methodology

This work provides experimental data on liquid−liquid equilibria in the range 288−328 K and data of HmE and VmE at temperatures of 298.15 and 318.15 K, for binary mixtures corresponding to 1-butyl-2-methylpyridinium tetrafluoroborate, [b2mpy][BF4], with alkanols (methanol to pentan-1-ol) and water. The [b2mpy][BF4] is completely miscible in water, and all the mixtures give positive values of HmE and VmE, giving increasing values of excess quantities with temperature. For mixtures with alkanols, values of HmE > 0 are obtained with VmE < 0, endothermic effects accompanied by contraction, with temperature changes represented by (dHmE/dT)p > 0 and (dVmE/dT)p > 0. Experimental data are correlated with a suitable equation and are presented together with those obtained in previous works for another two isomers, [b3mpy][BF4] and [b4mpy][BF4], and the properties of all of them are compared and discussed along with their behavior. The quantum-chemical method COSMO-RS is applied for the first time to predict excess properties of these mixtures containing ionic liquids, and the results show a significant contribution of hydrogen bond interactions in the behavior of the mixtures studied here, generically referred to as [bXmpy][BF4] (X = 2, 3, 4) + H2O or + CvH2v+1(OH) (v = 1−5).

Densities, Excess Molar Volumes, Viscosity, and Refractive Indices of Binary and Ternary Liquid Mixtures of Methanol (1) + Ethanol (2) + 1,2-Propanediol (3) at P = 81.5 kPa

Excess molar volume, VmE, and excess partial molar volume, ViE, of the ternary mixtures of methanol (1) + ethanol (2) + 1,2-propanediol (3) and of two binaries of methanol (1) + 1,2-propanediol (3) and ethanol (2) + 1,2-propanediol (3) have been investigated from the density, ρ, measurements over the entire range of compositions at temperatures (298.15, 303.15, and 308.15) K and at P = 81.5 kPa. The limiting values of the excess partial molar volumes at infinite dilution, ViE,∞, and thermal expansion coefficients, α, of the pure components are also evaluated. The dynamic viscosity, η, of the ternary and the relevant binary mixtures and the refractive indices, nD, of the binary mixtures at temperature 303.15 K were measured. The measured systems exhibited negative values of VmE and become more negative with increasing temperatures. The excess molar volumes, dynamic viscosity, and refractive index deviations were correlated with the Redlich−Kister and the Cibulka equations for the binary and ternary system, respectively. The excess molar volumes, VmE, of the binary mixtures were compared with values from the literature in the region of overlap.

Densities and Viscosities of 1-Butyl-3-methylimidazolium Tetrafluoroborate + Molecular Solvent Binary Mixtures

The densities and viscosities of 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] ionic liquid with methyl formate, methyl acetate, ethyl formate, and acetone have been measured at 298.15 K. The excess molar volume VmE and the viscosity deviations Δη for the binary mixture have been calculated and were fitted to the Redlich−Kister polynomials. The values of VmE and Δη are negative over the whole composition range. The minima in VmE and Δη are observed at about mole fraction of the ionic liquid, x ≈ 0.3 and 0.7, respectively.

Volumetric Properties of Binary and Ternary Liquid Mixtures of 1-Propanol (1) + 2-Propanol (2) + Water (3) at Different Temperatures and Ambient Pressure (81.5 kPa)

Excess molar volume, VmE, and excess partial molar volume, ViE, of the ternary mixtures of 1-propanol (1) + 2-propanol (2) + water (3) and of two binaries of 1-propanol (1) + water (3) and 2-propanol (2) + water (3) have been investigated from the density, ρ, measurements over the entire range of composition at temperatures (293.15, 303.15, 313.15, and 323.15) K and at ambient pressure (81.5 kPa). The limiting values of the excess partial molar volumes at infinite dilution, ViE,0, and thermal expansion coefficients, α, of the pure component are also evaluated. The systems exhibited negative values of VmE that increase with increasing temperatures. The excess molar volumes were correlated with the Redlich−Kister equation and the Cibulka equation for binary and ternary systems, respectively. The excess molar volumes, VmE, of the binary mixtures were compared with values from the literature in the region of overlap.

(p, Vm, T) measurements of (octane + benzene) at temperatures from (298.15 to 328.15) K and at pressures up to 40 MPa

The densities of (octane+benzene) were measured at elevated pressures (0.1 to 40)MPa at four temperatures over the range (298.15 to 328.15)K with a high-pressure apparatus. The high-pressure density data were fitted to the Tait equation and the isothermal compressibilities were calculated with a novel computation procedure with the aid of this equation. The low- and high-pressure values of excess molar volume VmE calculated from the density data show that the deviations from ideal behaviour in the system are practically independent of temperature and decreases slightly as the pressure is raised. The VmE data were fitted to the fourth-order Redlich–Kister equation, with the maximum likelihood principle being applied for the determination of the adjustable parameters.

Excess molar volumes of (octane + benzene, or toluene, or 1,3-xylene, or 1,3,5-trimethylbenzene) at temperatures between (298.15 and 328.15) K

The densities of (octane+benzene, or toluene, or 1,3-xylene, or 1,3,5-trimethylbenzene) were measured at temperatures (298.15, 308.15, 318.15, and 328.15)K by means of a vibrating-tube densimeter. The excess molar volumes VmE calculated from the density data provide the temperature dependence of VmE in the temperature range of (298 to 328)K. The VmE results were correlated using the fourth-order Redlich–Kister equation, with the maximum likelihood principle being applied for the determination of the adjustable parameters. It was found that the values of VmE are not very much dependent on temperature and in all cases decrease with the number of methyl groups on benzene ring of the alkylbenzene.

Liquid Densities and Excess Molar Volumes for Binary Systems (Ionic Liquids + Methanol or Water) at 298.15, 303.15 and 313.15 K, and at Atmospheric Pressure

Binary excess molar volumes, VmE, have been evaluated from density measurements, using a vibrating tube densimeter over the entire composition range for binary liquid mixtures of ionic liquids 1-ethyl-3-methyl-imidazolium diethyleneglycol monomethylethersulphate [EMIM]+[CH3(OCH2CH2)2OSO3]− or 1-butyl-3-methyl-imidazolium diethyleneglycol monomethylethersulphate [BMIM]+[CH3(OCH2CH2)2OSO3]− or 1-methyl-3-octyl-imidazolium diethyleneglycol monomethylethersulphate [MOIM]+[CH3(OCH2CH2)2OSO3]−+methanol and [EMIM]+[CH3(OCH2CH2)2OSO3]−+water at 298.15, 303.15 and 313.15 K. The VmE values were found to be negative for all systems studied. The VmE results are explained in terms of intermolecular interactions and packing effects. The experimental data were fitted by the Redlich-Kister polynomial.

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, VmE, partial molar volumes, \(\smash{\overline V _{m,1}^\circ }\) and \(\smash{\overline V _{m,2}^\circ }\), at infinite dilution, and excess partial molar volumes, \(\smash{\overline V _{m,1}^{\circ {\rm E}}}\) and \(\smash{\overline V _{m,2}^{\circ {\rm E}}}\), 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, \(\smash{\overline E _1^\circ}\) and \(\smash{\overline E _2^\circ}\), at infinite dilution and excess partial molar expansivities, \(\smash{\overline E _1^{\circ {\rm E}}}\) and \(\smash{\overline E _2^{\circ {\rm E}}}\), at infinite dilution were also calculated. The VmE 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 VmE values change sign from positive to negative as the concentration of FA in the mixture is increased. The VmE values for these mixtures follow the order: 1-butanol < 2-butanol < 1,3-butanediol < 1,4-butanediol. It is observed that the VmE values depend upon the number and position of hydroxyl groups in these alkanol molecules.

Volumetric properties of 1-iodoperfluorohexane+n-octane binary system at several temperatures

New densities are reported over the whole composition range for 1-iodoperfluorohexane+n-octane system at temperatures from 288.15 to 308.15 K at atmospheric pressure. These data have been used to compute the excess molar volumes, VmE. Large positive VmE values have been obtained over the entire range of composition, which increases when the temperature rises. The experimental data were used to calculate the isobaric thermal expansivity, and the quantities (∂VmE/∂T)p and (∂HmE/∂p)T. Furthermore, the results have been used to investigate the volumetric prediction ability of the equations of state Soave–Redlich–Kwong, Peng–Robinson, Patel–Teja and Soave–Redlich–Kwong with volume translation.

Volumetric Properties of Binary Mixtures of Isomeric Butanols and C8 Solvents at 298.15 K

Excess molar volumes, VmE, over the whole composition range for binary mixtures of 1-butanol, 2-butanol, and 2-methyl-2-propanol + 1-octanol, or 2-octanol, or di-n-butyl ether, or n-hexylacetate were determined at 298.15 K from density measurements carried out with a vibrating-tube densimeter. Small VmE values, both positive and negative, are displayed by mixtures containing 1- or 2-octanol, whereas positive and larger values are always found for mixtures containing dibutyl ether and hexylacetate. These results can be justified in terms of H-bonding interactions and/or steric hindrance due to the branched alkyl chains. Partial molar volumes at infinite dilution of the isomeric butanols in the C8 compounds were also calculated from the apparent molar volumes in dilute solution. The solute-solvent interactions and the effects of the local organisation of the solvent around the butanol molecules were discussed using the void and cavity volumes as different estimates of the intrinsic volume of the molecules. The volumetric behavior of butanols seems to be determined by the solute-solvent interactions rather than packaging effects.

Liquid Solution Densities of Ternary-Pseudobinary Mixtures of (Benzene + Cyclohexane) in the Presence of Tetrachloromethane or n-Hexane

Densities have been obtained as a function of composition for ternary-pseudobinary mixtures of [(benzene + tetrachloromethane or n-hexane) + (cyclohexane + tetrachloromethane or n-hexane)] at atmospheric pressure and the temperature 298.15 K, by means of a vibrating-tube densimeter. Excess molar volumes, VmE, partial molar volumes and excess partial molar volumes were calculated from the density data. The values of VmE have been correlated using the Redlich–Kister equation and the coefficients and standard errors were estimated. The experimental and calculated quantities are used to discuss the mixing behavior of the components. The results show that the third component, CCl4 or n-C6H14, have quite different influences on the volumetric properties of binary liquid mixtures of benzene with cyclohexane.

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, VmE, and excess logarithm viscosities, (lnη)E, have been determined for the binaries. It is shown that all values of VmE are negative but those of (lnη)E are positive. Interestingly, a minimum in VmE 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 VmE 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.

Effects of the Presence of Cyclohexane or Methylcyclohexane on the Densities and Volumetric Properties of the Mixture (Benzene + Propionitrile)

Excess molar volumes, VmE, have been obtained as a function of composition for ternary-pseudobinary mixtures of [(benzene + cyclohexane or methylcyclohexane) + (propionitrile + cyclohexane or methylcyclohexane)] from the densities measured by means of a vibrating-tube densimeter at atmospheric pressure and a temperature of 298.15 K. The values of VmE have been correlated using the Redlich–Kister equation to estimate the coefficients and standard errors. The experimental and calculated quantities are used to discuss the mixing behavior of the components. The results show that the third component, cyclohexane or methylcyclohexane, has a significant effect on the interaction between benzene and propionitrile.

Densities and Excess Molar Volumes of Binary and Ternary Mixtures of Aqueous Solutions of 2,2,2-Trifluoroethanol with Acetone and Alcohols at the Temperature of 298.15 K and Pressure of 101 kPa

Excess molar volumes VmE of the binary mixtures of (trifluoroethanol + 1-propanol), (trifluoroethanol + 2-propanol), (acetone + water), (methanol + water), (ethanol + water), (1-propanol + water), (2-propanol + water), and the ternary mixtures of (trifluoroethanol + methanol + water), (trifluoroethanol + ethanol + water), (trifluoroethanol~+ 1-propanol + water), (trifluoroethanol + 2-propanol + water) and (trifluoroethanol + acetone + water) were measured with a vibrating tube densimeter at the temperature of 298.15 K and the pressure 101 kPa. The extrema in VmE of trifluoroethanol mixtures occur at −0.690 cm3-mol−1 for (trifluoroethanol + 1-propanol), at −0.990~cm3-mol−1 for (trifluoroethanol + 2-propanol); at 0.562 and −0.973 cm3-mol−1 for (trifluoroethanol + methanol + water), at 0.629 and −0.973 cm3-mol−1 for (trifluoroethanol + ethanol + water), at 1.082 and −0.659 cm3-mol−1 for (trifluoroethanol~+ 1-propanol + water), at 0.998 and −0.991 cm3-mol−1 for (trifluoroethanol~+ 2-propanol + water), and at 0.515 and −1.472 cm3-mol−1 for (trifluoroethanol + acetone + water). The experimental ternary VmE values were predicted by empirical expressions using binary solution data.

Measurement of densities and excess molar volumes for (1,2-ethanediol, or 1,2-propanediol, or 1,2-butanediol + water) at the temperatures (278.15, 288.15, 298.15, 308.15, and 318.15) K and for (2,3-butanediol + water) at the temperatures (308.15, 313.15, and 318.15) K

Excess molar volumes of VmEof (1,2-ethanediol, or 1,2-propanediol, or 1,2-butanediol, or 2,3-butanediol + water) were measured atp= 0.1 MPa with a faithful copy of the vibrating tube densimeter DMA 602 from Anton Paar. All binary mixtures were measured at the temperatures (278.15, 288.15, 298.15, 308.15, and 318.15) K with exception of 2,3-butanediol + water, which was measured at the temperatures (308.15, 313.15, and 318.15) K, because 2,3-butanediol has a melting temperature of about T= 298.15 K. Values ofVmE are negative for all the mixtures studied over the whole concentration range and for all temperatures. Results were correlated by polynomial equations of Redlich and Kister.

Excess molar enthalpies and volumes of (1-hexyne, or 1-heptyne, or 1-octyne + di-1-methylethyl ether, or 1,1-dimethylethyl methyl ether, or 1,1-dimethylpropyl methyl ether) at the temperature 298.15 K

Excess molar enthalpies HmEand volumes VmEwere measured at T= 298.15 K and atmospheric pressure for (1-hexyne, or 1-heptyne, or 1-octyne + di-1-methylethyl ether, or 1,1-dimethylethyl methyl ether, or 1,1-dimethylpropyl methyl ether). The results were compared with the values of HmEfor the related mixtures, and the possible hydrogen bonding between the alkyne and the ether noted. Various theories of liquid mixtures were fitted with the results. The HmEresults were discussed in terms of the NRTL and UNIQUAC models, and were calculated by using the values of VmE(x= 0.5) by the Prigogine–Flory–Patterson (PFP) theory using Flory’s equation of state and a free volume contribution.

Excess molar volumes of 2-methylethylbenzene with benzene, methylbenzene or ethylbenzene at various temperatures

Excess molar volumes of benzene or methylbenzene + 2-methylethylbenzene at 25, 35 and 45°C and of ethylbenzene + 2-methylethylbenzene at 25°C have been determined from density measurements using a vibrating tube densimeter. Experimental VmE values have been compared with calculated values based on the Flory theory.