Excess properties and vapour pressure of (3-diethylaminopropylamine + n-alkanes)

The vapour pressures of liquid (3-diethylaminopropylamine (3-DEPA) + n-heptane) mixtures were measured by a static method between T = (303.15 and 343.15) K at 10 K intervals. The molar excess enthalpies H^E at T = 303.15 K were measured for the systems {3-DEPA + C_nH_2n+2 (n = 6, 7, 12)}. The molar excess Gibbs free energies G^E were obtained with Barker’s method and fitted to the Redlich–Kister equation. The Wilson equation was also used. Deviations between experimental and predicted G^E and H^E, by using group contribution UNIFAC (Gmehling version) model, were evaluated.     

Thermodynamics of isomeric hexynes + MTBE binary mixtures

The vapor pressures of liquid hex-1-yne or hex-2-yne + methyl 1,1-dimethylethyl ether (MTBE) binary mixtures and of the three pure components were measured by a static method at several temperatures between 263 and 343 K. These data were correlated with the Antoine equation. Excess molar Gibbs energies G^E were calculated for several constant temperatures, taking into account the vapor-phase imperfection in terms of the second molar virial coefficients, and were fitted to the Redlich–Kister equation. Calorimetric excess enthalpy H^E measurements, for these binary mixtures, are also reported at 298.15 K. The experimental VLE and H^E data were used, examining the binary mixtures hex-1-yne or hex-2-yne + MTBE in the framework of the DISQUAC and modified UNIFAC (Do) models. The DISQUAC calculations, reporting a new set of interaction parameters for the contact carbon–carbon triple bond/oxygen ether, is regarded as a preliminary approach.     

(Vapour + liquid) equilibria and excess Gibbs free energies of (cyclohexanone + 1-chlorobutane and + 1,1,1-trichloroethane) binary mixtures at temperatures from (298.15 to 318.15) K

The vapour pressures of binary (cyclohexanone + 1-chlorobutane, + 1,1,1-trichloroethane) mixtures were measured at the temperatures of (298.15, 308.15, and 318.15) K. The vapour pressures vs. liquid phase composition data have been used to calculate the excess molar Gibbs free energies G^E of the investigated systems, using Barker’s method. Redlich–Kister, Wilson, UNIQUAC, and NRTL equations, taking into account the vapour phase imperfection in terms of the 2-nd virial coefficient, have represented the G^E values. No significant difference between G^E values obtained with these equations has been observed.     

Isothermal (vapour + liquid) equilibria and excess Gibbs free energies in some binary (cyclopentanone + chloroalkane) mixtures at temperatures from 298.15 K to 318.15 K

The vapour pressures of binary (cyclopentanone + 1-chlorobutane, +1,3-dichloropropane, and +1,4-dichlorobutane) mixtures, were measured at the temperatures of (298.15, 308.15, and 318.15) K. The vapour pressures vs. liquid phase composition data have been used to calculate the excess molar Gibbs free energies G^E of the investigated systems, using Barker’s method. Redlich–Kister, Wilson and NRTL equations, taking into account the vapor phase imperfection in terms of the second virial coefficient, have represented the G^E values. No significant difference between G^E values obtained with these equations has been observed.     

(Vapor-liquid) equilibria and excess Gibbs free energy functions of (ethanol + glycerol), or (water + glycerol) binary mixtures at several temperatures

The vapor pressures of (ethanol + glycerol) and (water + glycerol) binary mixtures were measured by means of two static devices at temperatures between (273 and 353 (or 363)) K. The data were correlated with the Antoine equation. From these data, excess Gibbs free energy functions (G^E) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker method. The (ethanol + glycerol) binary system exhibits positive deviations in G^E where for the (water + glycerol) mixture, the G^E is negative for all temperatures investigated over the whole composition. Additionally, the NRTL, UNIQUAC and Modified UNIFAC (Do) models have been used for the correlation or prediction of the total pressure.     

Experimental determination of the isothermal (vapour + liquid) equilibria of binary aqueous solutions of sec-butylamine and cyclohexylamine at several temperatures

The vapour pressures of (sec-butylamine + water), (cyclohexylamine + water) binary mixtures, and of pure sec-butylamine and cyclohexylamine components were measured by means of two static devices at temperatures between 293 (or 273) K and 363 K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions (G^E) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker’s method. The (cyclohexylamine + water) system shows positive azeotropic behaviour for all investigated temperatures. The two binary mixtures exhibit positive deviations in G^E for all investigated temperatures over the whole composition range.     

Measurements of HmE and VmE for (n-butane + sulphur hexafluoride) in the supercritical region at the pressure 6.00 MPa

A flow mixing calorimeter followed by a vibrating-tube densimeter has been used to measure excess molar enthalpies H_m^E and excess molar volumes V_m^E of {xC₄H₁₀+(1−x)SF₆}. Measurements over a range of mole fractions x have been made in the supercritical region at the pressure p=6.00 MPa and at seven temperatures in the range T=311.25 K to T=425.55 K. The H_m^E(x) measurements at T=351.35 K were found to exhibit an unusual double maximum. Measurements at all temperatures are compared with the Patel–Teja equation of state with the parameters determined by solving a cubic equation as recommended, and also with parameters determined by the method suggested by Valderamma and Cisternas who proposed equations which are a function of the critical compression factor. The overall fit to the H_m^E and V_m^E measurements obtained using Valderamma and Cisternas equations was found to be better than that obtained using the parameters according to the method suggested by Patel and Teja.     

Study of densities,viscosities, and speeds of sound of binary liquid mixtures of butan-1-ol with n-alkanes (C6, C8, and C10) at T = (298.15, 303.15, and 308.15) K

The densities (ρ) and speeds of sound (u) have been measured over the whole composition range for (butan-1-ol with hexane, or octane, or decane) at T = (298.15, 303.15, and 308.15) K and atmospheric pressure along with the properties of the pure components. Viscosities (η) of these binary mixtures have also been measured over the entire composition range at T = 298.15 K. Experimental values of density, viscosity and speed of sound have been used to evaluate excess properties viz. excess molar volumes (V^E), deviation in viscosity (Δη), deviation in speeds of sound (Δu), deviation in isentropic compressibility (Δκ_s) and excess Gibbs free energy of activation of viscous flow (ΔG^1E). The excess properties have been correlated using the Redlich–Kister polynomial equation. The sign and magnitude of these excess properties have been used to interpret the results in terms of intermolecular interactions and structural effects. The viscosity data have also been correlated by Grunberg and Nissan, Tamura–Kurata, and Hind correlation equations.     

Investigation of the isothermal (vapour + liquid) equilibria of aqueous 2-amino-2-methyl-1-propanol (AMP), N-benzylethanolamine,or 3-dimethylamino-1-propanol solutions at several temperatures

The vapour pressures of (2-amino-2-methyl-1-propanol (AMP) + water), (N-benzylethanolamine + water), or (3-dimethylamino-1-propanol + water) binary mixtures, and of pure AMP and 3-dimethylamino-1-propanol components were measured by means of two static devices at temperatures between 283 K and 363 K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions (G^E) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker’s method. The {2-amino-2-methyl-1-propanol (AMP) + water} binary mixture exhibits negative deviations in G^E (at T < 353.15 K) and a sinusoidal shape for G^E for the higher temperatures over the whole composition range. For the aqueous N-benzylethanolamine solution, a S shape is observed for the G^E for all investigated temperatures over the whole composition range. The (3-dimethylamino-1-propanol + water) binary mixture exhibits negative deviations in G^E (at T < 293.15 K), positive deviations in G^E (for 293.15 K < T < 353.15 K) and a sinusoidal shape for G^E for the higher temperatures over the whole composition range.     

Excess parameters of binary mixtures of anisaldehyde with o-cresol,m-cresol and p-cresol at T = (303.15, 308.15, 313.15, and 318.15) K

The density, ultrasonic velocity, and viscosity of binary mixtures of (anisaldehyde + o-cresol, or +m-cresol, or +p-cresol) have been measured over the entire range of composition at T = (303.15, 308.15, 313.15, and 318.15) K. Using these data, various thermo-acoustic parameters such as deviation in adiabatic compressibility, Δβ, excess molar volume, V^E, viscosity deviation, Δη and excess Gibb’s free energy of activation for viscous flow, ΔG^1E have been calculated. The calculated deviation and excess functions have been fitted to the Redlich–Kister polynomial equation. The negative and positive values of deviation or excess thermo-acoustic parameters observed have been explained on the basis of the intermolecular interactions present in these mixtures.     

(Vapour + liquid) equilibria and excess molar enthalpies for mixtures with strong complex formation. Trichloromethane or 1-bromo-1-chloro-2,2,2-trifluoroethane (halothane) with tetrahydropyran or piperidine

Isothermal (vapour  +  liquid) equilibria were measured for (trichloromethane  +  tetrahydropyran or piperidine) at T =  333.15 K and {1-bromo-1-chloro-2,2,2-trifluoroethane (halothane)  +  tetrahydropyran or piperidine} atT =  323.15 K with a circulation still. The results were verified by effective statistical procedures and used to calculate activity coefficients and excess molar Gibbs free energiesG_m^E . Excess molar enthalpiesH_m^E for these mixtures were determined at T =  298.15 K by means of an isothermal CSC microcalorimeter equipped with recently reconstructed flow mixing cells. Reliable performance of the calorimetric setup was proved by the good agreement of H_m^Efor (hexane  +  cyclohexane), (2-propanone  +  water), and (methanol  +  water), with the best literature results. The trichloromethane- or halothane-containing mixtures exhibit strong negative deviations from Raoult’s law and are highly exothermic, thus indicating that complex formation via hydrogen bonding is a governing nonideality effect. A close similarity in the behaviour of corresponding mixtures with trichloromethane and halothane is observed, but for halothane-containing mixtures,G_m^E and H_m^Eare consistently more negative, confirming that halothane is a more powerful proton donor than chloroform.     

Effect of temperature on the excess molar volumes of some alcohol + aromatic mixtures and modelling by cubic EOS mixing rules

Densities of the (methanol + benzene), (ethanol + benzene), (methanol + chlorobenzene) and (ethanol + chlorobenzene) mixtures have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15 and 313.15 K) and 101.33 kPa. Excess molar volumes V^E were determined and fitted by the Redlich–Kister equation. It was observed that in all cases V^E increases with rising of temperature. The values of limiting excess partial molar volumes have been calculated, as well. The obtained results have been analysed in terms of specific molecular interactions present in these mixtures taking into considerations effect of temperature on them. The correlation of V^E binary data was performed with the Peng–Robinson–Stryjek–Vera cubic equation of state (PRSV CEOS) coupled with the van der Waals (vdW1) and CEOS/G^E mixing rule introduced by Twu, Coon, Bluck and Tilton (TCBT). The experimental values of V^E were compared with those estimated by both mixing rules at the temperature range and on each temperature, separately.     

Excess molar enthalpies of binary systems containing 2-octanone,hexanoic acid,or octanoic acid at T = 298.15 K

An isothermal titration calorimeter was used to measure the excess molar enthalpies (H^E) of six binary systems at T = 298.15 K under atmospheric pressure. The systems investigated include (1-hexanol + 2-octanone), (1-octanol + 2-octanone), (1-hexanol + octanoic acid), (1-hexanol + hexanoic acid), {N,N-dimethylformamide (DMF) + hexanoic acid}, and {dimethyl sulfoxide (DMSO) + hexanoic acid}. The values of excess molar enthalpies are all positive except for the DMSO- and the DMF-containing systems. In the 1-hexanol with hexanoic acid or octanoic acid systems, the maximum values of H^E are located around the mole fraction of 0.4 of 1-hexanol, but the H^E vary nearly symmetrically with composition for other four systems. In addition to the modified Redlich–Kister and the NRTL models, the Peng–Robinson (PR) and the Patel–Teja (PT) equations of state were used to correlate the excess molar enthalpy data. The modified Redlich–Kister equation correlates the H^E data to within about experimental uncertainty. The calculated results from the PR and the PT are comparable. It is indicated that the overall average absolute relative deviations (AARD) of the excess enthalpy calculations are reduced from 18.8% and 18.8% to 6.6% and 7.0%, respectively, as the second adjustable binary interaction parameter, k_bij, is added in the PR and the PT equations. Also, the NRTL model correlates the H^E data to an overall AARD of 10.8% by using two adjustable model parameters.     

Thermodynamics of mixtures with strongly negative deviations from Raoult's law: Part 9. Vapor–liquid equilibria for the system 1-propanol + di-n-propylamine at six temperatures between 293.15 and 318.15 K

Vapor pressures of the 1-propanol + di-n-propylamine (DPA) system at six different temperatures between 293.15 and 318.15 K were measured by a static method. The reduction of the experimental data to obtain molar excess Gibbs energies, G^E was carried out according to Barker's method, assuming that G^E is represented by a Redlich–Kister equation. In the temperature range considered, the mixture shows azeotropic behaviour and negative deviation from the Raoult's law. DISQUAC describes better than the ERAS or UNIFAC (Dortmund version) models the experimental data. The analysis of the mixture structure in terms of the so-called concentration–concentration structure factor, S_cc(0) reveals that interactions between unlike molecules occur in such a way that several molecules of amine interact with one molecule of alcohol.     

Excess molar enthalpies and excess molar volumes of (1,3-dimethyl-2-imidazolidinone + an aromatic hydrocarbon) atT = 298.15 K

Excess molar enthalpies H_m^Eand excess molar volumesV_m^E of (1,3-dimethyl-2-imidazolidinone  +  benzene, or methylbenzene, or 1,2-dimethylbenzene, or 1,3-dimethylbenzene, or 1,4-dimethylbenzene, or 1,3,5-trimethylbenzene, or ethylbenzene) over the whole range of compositions have been measured at T =  298.15 K. The excess molar enthalpy values were positive for five of the seven systems studied and the excess molar volume values were negative for six of the seven systems studied. The excess enthalpy ranged from a maximum of 435 J · mol ^− 1for (1,3-dimethyl-2-imidazoline  +  1,3,5-trimethylbenzene) to a minimum of  − 308 J · mol ^− 1for (1,3-dimethyl-2-imidazoline  +  benzene). The excess molar volume values ranged from a maximum of 0.95cm³mol ^− 1 for (1,3-dimethyl-2-imidazoline  +  ethylbenzene) and a minimum of  − 1.41 cm³mol ^− 1for (1,3-dimethyl-2-imidazoline  +  methylbenzene). The Redlich–Kister polynomial was used to correlate both the excess molar enthalpy and the excess molar volume data and the NRTL and UNIQUAC models were used to correlate the enthalpy of mixing data. The NRTL equation was found to be more suitable than the UNIQUAC equation for these systems. The results are discussed in terms of the polarizability of the aromatic compound and the effect of methyl substituents on the benzene ring.     

Phase equilibrium properties of binary mixtures containing 1,3-pentanediamine (or 1,5-diamino-2-methylpentane) and water at several temperatures

The vapor pressures of (1,3-pentanediamine + water), or (1,5-diamino-2-methylpentane + water) binary mixtures, and of pure 1,3-pentanediamine or 1,5-diamino-2-methylpentane components were measured by means of a static device at temperatures between (273 and 363) K. The data were correlated with the Antoine equation. From these data excess Gibbs functions (G^E) were calculated for several constant temperatures and fitted to a three order Redlich–Kister equation using the Barker’s method. The (1,3-pentanediamine + water) or (1,5-diamino-2-methylpentane + water) binary systems exhibit negative deviations in G^E for all investigated temperatures over the whole composition. Additionally, the NRTL UNIQUAC and Modified UNIFAC (Do) models have been used for the correlation or prediction of the total pressure.     

Phase equilibrium properties of binary aqueous solutions containing ethanediamine, 1,2-diaminopropane, 1,3-diaminopropane,or 1,4-diaminobutane at several temperatures

The vapour pressures of {ethanediamine (EDA) + water}, {1,2-diaminopropane (1,2-DAP) + water}, {1,3-diaminopropane (1,3-DAP) + water} or {1,4-diaminobutane (1,4-DAB) + water} binary mixtures, and of pure EDA, 1,2-DAP, 1,3-DAP, 1,4-DAB, and water components were measured by means of two static devices at temperatures between (293 and 363) K. The data were correlated with the Antoine equation. From these data, the excess Gibbs function (G^E) was calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker’s method. The {ethanediamine (EDA) + water}, and {1,2-diaminopropane (1,2-DAP) + water} binary systems show negative azeotropic behaviour. The aqueous solutions of EDA, 1,2-DAP, or 1,3-DAP exhibit negative deviations in G^E for all investigated temperatures over the whole composition range whereas the (1,4-DAB + water) binary mixture shows negative G^E for temperatures (293.15 < T/K < 353.15) and a sinusoidal shape for G^E at T = 363.15 K.     

Phase equilibrium properties of binary aqueous solutions of benzylamine, 1,2-bis(2-aminoethoxy)ethane,or 2-[2-(dimethylamino)ethoxy]ethanol

The vapour pressures of (benzylamine + water), {1,2-bis(2-aminoethoxy)ethane + water}, or {2-[2-(dimethylamino)ethoxy]ethanol + water} binary mixtures, and pure 2-[2-(dimethylamino)ethoxy]ethanol component were measured by means of two static devices at temperatures between (283.15 and 363.15 (or 323.15)) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions (G^E) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker’s method. The (benzylamine + water) binary mixture exhibits positive deviations in G^E for (303.15 < T/K < 323.15) and a sinusoidal shape in G^E for T > 323.15 K over the whole composition range. The aqueous 1,2-bis(2-aminoethoxy)ethane or {2-[2-(dimethylamino)ethoxy]ethanol + water} solutions exhibit negative deviations in G^E for all investigated temperatures over the whole composition range.     

Excess molar enthalpies of binary mixtures containing 2-decanone or dipentyl ether with long-chain n-alkanes at T = 298.15 K

Excess molar enthalpies (H^E) of binary mixtures of 2-decanone or dipentyl ether with n-alkanes, including n-dodecane, n-tetradecane, and n-hexadecane, were measured with an isothermal titration calorimeter (ITC) at T = 298.15 K under atmospheric pressure. All the measured H^E values are positive over the entire range of composition, indicating that all these mixing processes are endothermic. The H^E values varying with composition are found to be nearly symmetric for each binary system. It was also shown that the H^E values follow the order of n-hexadecane > n-tetradecane > n-dodecane at a given composition in either the 2-decanone or dipentyl ether binary systems. An empirical Redlich–Kister equation correlated quantitatively these new H^E data. The Peng–Robinson and the Patel–Teja equations of state, and the NRTL model were also applied to fit the H^E results. Among these tested correlative models, the Patel–Teja equation of state with two adjustable binary interaction parameters generally yielded the best representation.     

Densities,surface tensions,and derived surface thermodynamics properties of (trimethylbenzene + propyl acetate,or butyl acetate) from T = 298.15 K to 313.15 K

Densities (ρ) for binary systems of (1,2,4-trimethylbenzene, or 1,3,5-trimethylbenzene + propyl acetate, or butyl acetate) were determined at four temperatures (298.15, 303.15, 308.15, and 313.15) K over the full mole fraction range. The excess molar volumes (V^E) calculated from the density data show that the deviations from ideal behaviour in the systems (all being positive, excepting 1,2,4-trimethylbenzene + butyl acetate system) become more positive with the temperature increasing. Surface tensions (σ) of these binary systems were measured at the same temperatures (298.15, 303.15, 308.15, and 313.15) K by the pendant drop method, the surface tension deviations (δσ) for all system are negative, and decrease with the temperature increasing. The V^E and δσ are fitted to the Redlich–Kister polynomial equation. Surface tensions were also used to estimate surface entropy (S_σ) and surface enthalpy (H_σ).