Speeds of sound and isentropic compressibil- ities of cyclohexane+1,3-dioxolane+2-butanol and n-hexane+1,3-dioxolane+2-butanol

Speeds of sound of the ternary mixtures cyclohexane+1,3-dioxolane+2-butanol and n-hexane+1,3-dioxolane+2-butanol have been measured at the temperatures of 298.15 and 313.15 K. Isentropic compressibilities and excess isentropic compressibilities have been calculated from experimental data. We have also compared the experimental isentropic compressibilities with calculated values from the free length theory and the collision factor theory. Experimental results show positive values of excess isentropic compressibilities in almost the whole composition range for the ternary mixture containing cyclohexane, meanwhile they are negative for the mixture containing n-hexane. Such different behaviour of these systems is related to the large free volume shown by n-hexane. This revised version was published online in July 2006 with corrections to the Cover Date.     

Volumetric and acoustic properties of the ternary system (1-butanol+1,4-dioxane+cyclohexane)

Densities and speeds of sound for the ternary system 1-butanol+1,4-dioxane+cyclohexane have been measured at the temperatures of 298.15 and 313.15 K. Excess molar volumes and excess isentropic compressibilities have been calculated from experimental data and fitted by the Redlich-Kister equation for ternary mixtures. The ERAS model has been used to calculate excess molar volumes of the ternary mixture from parameters obtained from the constituent binary mixtures.     

Spectroscopic and acoustic study in binary mixtures of glycerol with several alkanols

Speeds of sound and densities of glycerol + methanol, glycerol + ethanol and glycerol + 2-propanol, were measured over the entire composition range at 298.15 K. The excess volumes, the isentropic compressibilities, molar isentropic compressibilities and excess molar isentropic compressibilities and excess speeds of sound were estimated from the densities and speeds of sound. The results indicated the presence of interactions between unlike molecules through intermolecular hydrogen bonding. The excess volumes, excess molar isentropic compressibilities and excess speeds of sound of the binary mixtures were fitted to the Redlich–Kister equation. The infrared spectra of glycerol + methanol, glycerol + ethanol and glycerol + 2-propanol have been recorded for various concentrations at room temperature. IR stretching frequencies, bandwidths and relative intensities have been estimated and analysed. Acoustic and spectroscopic measurements showed a good correlation to explain the existence of interactions between unlike molecules through intermolecular hydrogen bonding.     

Studies on Intermolecular Interactions in Liquid Mixtures of Alkoxyalkanols and Branched Alcohols by Volumetric and Acoustic Measurements at Different Temperatures

Densities and speeds of sound for binary mixtures of diethylene glycol monomethyl ether and triethylene glycol monomethyl ether with 3-methyl-1-butanol and 2-methyl-2-butanol were measured at 288.15, 298.15 and 308.15 K, over the entire range of compositions at atmospheric pressure, using an Anton Paar DSA 5000 density meter. The experimental densities and speeds of sound have been used to calculate excess molar volumes and excess molar isentropic compressibilities. The speed of sound data are compared with theoretical speeds of sound calculated using several approaches.     

Binary mixtures of cyclohexanone, 2-butanone, 1,4-dioxane and 1,2-dimethoxyethane

Densities and sound velocities of binary mixtures of cyclohexanone, 2-butanone, 1,4-dioxane and 1,2-dimethoxyethane were measured at 298.15 K and also the densities at 303.15 K. Excess volumes were determined from densities. Isentropic compressibilities were determined from densities and sound velocities, and excess thermal expansion factors were determined from excess volumes of two temperatures. Excess isothermal compressibilities and excess isochoric heat capacities were then estimated using excess isobaric heat capacities previously reported. Excess volumes and excess isentropic and isothermal compressibilities were negative except for cyclohexanone+1,4-dioxane system. This revised version was published online in August 2006 with corrections to the Cover Date.     

Densities,speeds of sound and isentropic compressibilities of binary and ternary mixtures containing benzene,cyclohexane and hexane at 298.15 K

Densities, ϱ, and speeds of sound, u, have been measured for the ternary mixture {benzene + cyclohexane + hexane} and the corresponding binary mixtures {benzene + cyclohexane}, {benzene + hexane} and {cyclohexane + hexane}, at the temperature 298.15 K. Using these results, the isentropic compressibilities, κ_s, the excess isentropic compressibilities, κ_s^E, and the speeds of sound deviations, Δu, have been calculated for both the binary mixtures and the ternary system. Excess isentropic compressibilities, κ_s^E, and the speeds of sound deviations, Δu, have been fitted to the Redlich-Kister equation in the case of binary mixtures, while the equation of Cibulka was used to fit the values relating to the ternary system. The empiric equations of Redlich-Kister, Tsao-Smith, Kohler and Colinet have been applied in order to predict the κ_s^E and Δu of ternary mixtures from the binary contributions.     

Volumetric and acoustic behaviour of systems containing n-hexane,or n-heptane and isomeric chlorobutanes

Densities and speeds of sound at atmospheric pressure and temperatures of (283.15, 298.15, and 313.15) K for the binary mixtures formed by n-hexane or n-heptane with isomeric chlorobutanes were determined. Afterwards excess volumes, excess isentropic compressibilities and excess speeds of sound were calculated using the experimental data and correlated using a Redlich–Kister type equation. Finally, the results were studied using the Prigogine–Flory–Patterson theory showing excellent predictions for speed of sound and isentropic compressibility values of mixtures as well as a strong influence of the interactional contribution term for excess volume values.     

Physico-chemical properties of binary mixtures of 1-butanol with chloroethanes or chloroethenes at 298.15 K

The densities ρ, speeds of sound u, and viscosities η, of pure 1-butanol, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene, and tetrachloroethylene and those of their binary mixtures have been measured at 298.15 K and atmospheric pressure over the entire range of compositions. Excess molar volumes V ^E, viscosity deviations Δη, deviation in compressibilities Δκ_s and excess Gibbs energy of activation G*^E, were obtained from the experimental results and those were fitted to Redlich–Kister's type function in terms of mole fractions. Viscosities, speeds of sound and isentropic compressibilities of the binary mixtures have been correlated by means of several empirical and semi-empirical equations. The experimental data are analysed to discuss the nature and strength of intermolecular interactions in these mixtures.     

Excess properties of the ternary system cyclohexane + 1,3-dioxolane + 1-butanol at 298.15 and 313.15 K

Densities, speeds of sound and heats of mixing for the ternary system cyclohexane + 1,3-dioxolane + 1-butanol have been measured at atmospheric pressure at the temperatures of 298.15 and 313.15 K. Excess molar volumes, excess isentropic compressibilities and excess molar enthalpies have been calculated from experimental data and fitted by Cibulka equation. Excess molar properties were analysed in terms of molecular interactions and structural and packing effects.     

Excess properties of the ternary system (hexane + 1,3-dioxolane + 1-butanol) at 298.15 and 313.15 K

Densities, speeds of sound and heats of mixing for the ternary system hexane+1,3-dioxolane+1-butanol have been measured at atmospheric pressure at the temperatures of 298.15 and 313.15 K. Excess molar volumes, excess isentropic compressibilities, and excess molar enthalpies have been calculated from experimental data and fitted by Cibulka equation. Excess molar properties were analysed in terms of molecular interactions as well as structural and packing effects.     

Molar volumes,viscosity, and isentropic compressibility of some primary monoalkanols in aqueous N,N-dimethylformamide solutions

The densities (ρ) and viscosities (η) for the ternary liquid mixtures of water + N,N-dimethylformamide + monoalkanols, have been measured as a function of the composition at 298.15, 308.15, and 318.15 K. From the experimental measurements excess molar volumes (V ^E), Viscosity deviation (Δη), and synergy index (I _s) have been evaluated. The speeds of sound have been also measured and excess isentropic compressibilities (K _s^E) are calculated al 298.15 K. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding, been investigated.     

Isentropic expansion and related thermodynamic properties of non-ionic amphiphile-water mixtures

A concise thermodynamic formalism is developed for the molar isentropic thermal expansion, ES,m = ( partial differential Vm/ partial differential T)(Sm,x), and the ideal and excess quantities for the molar, apparent molar and partial molar isentropic expansions of binary liquid mixtures. Ultrasound speeds were determined by means of the pulse-echo-overlap method in aqueous mixtures of 2-methylpropan-2-ol at 298.15 K over the entire composition range. These data complement selected extensive literature data on density, isobaric heat capacity and ultrasound speed for 9 amphiphile (methanol, ethanol, propan-1-ol, propan-2-ol, 2-methylpropan-2-ol, ethane-1,2-diol, 2-methoxyethanol, 2-ethoxyethanol or 2-butoxyethanol)-water binary systems, which form the basis of tables listing molar and excess molar isobaric expansions and heat capacities, and molar and excess molar isentropic compressions and expansions at 298.15 K and at 65 fixed mole fractions spanning the entire composition range and fine-grained in the water-rich region. The dependence on composition of these 9 systems is graphically depicted for the excess molar isobaric and isentropic expansions and for the excess partial molar isobaric and isentropic expansions of the amphiphile. The analysis shows that isentropic thermal expansion properties give a much stronger response to amphiphile-water molecular interactions than do their isobaric counterparts. Depending on the pair property-system, the maximum excess molar isentropic value is generally twenty- to a hundred-fold greater than the corresponding maximum isobaric value, and occurs at a lower mole fraction of the amphiphile. Values at infinite dilution of the 9 amphiphiles in water are given for the excess partial molar isobaric heat capacity, isentropic compression, isobaric expansion and isentropic expansion. These values are interpreted in terms of the changes occurring when amphiphile molecules cluster into an oligomeric form. Present results are discussed from theoretical and experimental thermodynamic viewpoints. It is concluded that isentropic thermal expansion properties constitute a new distinct resource for revealing particular features and trends in complex mixing processes, and that analyses using these new properties compare favourably with conventional approaches.     

Speed of Sound and Isentropic Compressibilities of N-Methylcyclohexylamine with Benzene and Substituted Benzenes at 303.15 K

Abstract

New experimental sound velocity and density data for binary mixtures of N-methyl-cyclohexylamine with benzene, toluene, o-xylene, m-xylene, p-xylene, chlorobenzene, bromobenzene and nitrobenzene at 303.15K have been reported. The sound velocity data were also used to compute the isentropic compressibilities (K_s ). The deviation in isentropic compressibilities (ΔK_s ) from ideal behaviour suggests that the existence of weak dipole-induced dipole and dipole-dipole interactions between unlike molecules.     

Densities,speeds of sound,excess volumes and viscosities of binary mixtures of mtbe with tetralin and decalin at 303.15 k

Measurements of densities, speeds of sound, excess volumes and viscosities of binary mixture of methyl tert-butyl ether with tetralin and decalin are reported at 303.15?K over the entire range of composition. Excess volumes are measured using batch dilatometer technique. Sound speeds are obtained using ultrasonic interferometer. Densities are computed from excess volume data. Isentropic compressibilities are derived from density and sound speed data. Speeds of sound are evaluated on the basis of Jacobson's free length theory and Schaff's collision factor theory. The predicted values are in good agreement with the experimental results. The viscosity data are analysed on the basis of corresponding states approach. Excess volumes and deviation in isentropic compressibilities are negative and deviation in viscosities are positive over the entire composition range. The experimental results are discussed in terms of possible molecular interactions between unlike molecules.     

Physical Properties of the Ternary Mixture Ethanol+Water+1-Butyl-3-Methylimidazolium Chloride at 298.15 K

In this work densities, refractive indices, speeds of sound and isentropic compressibilities of the ternary mixture ethanol+water+1-butyl-3-methylimidazolium chloride ([C₄mim][Cl]), and of the binary subsystems containing the ionic liquid, have been measured at 298.15 K and atmospheric pressure.     

Acoustical Studies of Binary Liquid Mixtures of Cyclopentane with 1-Alkanol at Different Temperatures and Different Approaches for Ideal Mixing Laws

Speeds of sound have been measured in liquid mixtures of cyclopentane with 1-propanol, with 1-pentanol, and with 1-heptanol across the entire composition range at temperatures of (298.15, 308.15 and 318.15) K and atmospheric pressure. The experimental speed of sound data were used to estimate the isentropic compressibility κ _S for all mixtures. The molar volumes were multiplied by the corresponding isentropic compressibilities to obtain estimates of the molar compressibilities K _S,m. The corresponding K_S,m^EK_{S,\mathrm{m}}^{\mathrm{E}} values have also been calculated. Theoretical values of the speeds of sound were estimated using theories and empirical relations. Deviations of the speed of sound, u ^D, from the values calculated by different approaches for ideal mixing have been obtained for all mole fractions.     

Determination of the second critical micelle concentration of benzyldimethyltridecylazanium chloride in aqueous solution by acoustic and conductometric measurements

Density, speed of sound, and conductivity of benzyldimethyltridecylazanium chloride as a cationic surfactant in aqueous solutions have been measured as a function of concentration at atmospheric pressure and at five temperatures (293.15, 298.15, 303.15, 308.15, and 313.15) K. Isentropic compressibility values have also been calculated from the experimental density and speed of sound results. The critical micelle concentration (cmc) values of investigated cationic surfactant were evaluated by using conductivity measurements. The speed of sound, isentropic compressibility and also the conductivity values of the solutions have been employed to determine the second critical micelle concentrations (2nd cmc). The temperature dependence of the speed of sound and isentropic compressibility is shown to be sensitive to the aggregation process. The 2nd cmc values of the surfactant obtained at different temperatures by conductivity, speeds of sound and isentropic compressibility data are in agreement with each other.     

Isentropic partial molal compressibilities of alcohols in propylene carbonate at 25°C

The isentropic coefficients of compressibility of the homologous series of alcohols and diols R _n CH₂OH (n=2–6), CH₃CHOHR _n (n=1–5), 1,2-propanediol, 1,3- 1,4- and 2,3-butanediol, 1,5-pentanediol, and 1,7-heptanediol dissolved in propylene carbonate have been measured at 25°C. Isentropic partial molal compressibilities and group partial molal compressibilities at infinite dilution have been evaluated. The isentropic partial molal compressibilities of these alcohols and diols have been compared with the corresponding values in water. This comparison shows that the values in propylene carbonate are higher than in water by a factor of 10 due to an increased compressibility of the solvation sheath around nonpolar groups in PC.     

Phase equilibrium and thermophysical properties of mixtures containing a cyclic ether and 1-chloropropane

The phase equilibrium, at T = 298.15 and 313.15 K and several thermophysical properties (density, sound velocity, refractive index) at T = 283.15, 298.15 and 313.5 K of mixtures formed by a cyclic ether (tetrahydropyran, tetrahydrofuran) and 1-chloropropane has been studied. Excess Gibbs functions, excess volumes, excess isentropic compressibilities and refractive index deviations have been obtained from the experimental data. Both the molecular characteristics of the pure compounds and the molecular interactions in the mixing process have been used to analyse the results.