Experimental Excess Molar Volumes Research Articles

Unusual Hydration Properties of Choline Fluoride-Based Deep Eutectic Solvents.

The hydration properties of the fluoride-based deep eutectic solvent ethalineF [a solution of choline fluoride in ethylene glycol (EG) at a 1:2 molar ratio] are studied and compared to the most common deep eutectic solvent ethaline (the solution of choline chloride in EG at 1:2 molar ratio). The densities of the deep eutectic solvent (DES) based on choline fluoride in EG (ethalineF) and its mixtures with water as cosolvent are measured over the temperature range of 298-323 K. The excess properties, including excess molar volumes, excess partial molar volumes, and viscosity deviations from ideal behavior, are calculated for ethalineF/water and ethaline/water mixtures and compared. The experimental excess molar volumes and viscosity deviations of the studied pseudobinary mixtures are fitted using the Redlich-Kister (R-K) equation. The results of the R-K model successfully reproduced the experimentally calculated values with minimal standard deviations. All excess molar volumes and viscosity deviations had negative values, indicating stronger solvation interactions between the mixture components than between each pure DES or water. The excess partial molar volumes show that water molecules are preferentially solvated by the DES environment. We show that the disruption of the DES interactions (primarily OH...halide interactions) by high mole fractions of water is related to the peak ionic conductivity. The stark differences in hydration behavior between fluoride- and chloride-based ethaline are analyzed and discussed.

Study of the thermophysical properties for aqueous alkanediols binary mixtures

The thermophysical properties data as densities, speeds of sound, and refractive indices for aqueous binary mixtures of 1,2-hexanediol and 1,5-pentanediol, have been measured at several temperatures in the range of (298.15–318.15) K, atmospheric pressure, and in the whole domain (0 to 1) of diol molar fractions.From the obtained experimental values, the related excess and deviation quantities, namely the excess molar volumes, the partial/apparent molar volumes, the isentropic compressibilities, the excess isentropic compressibilities and the deviation in refractive indices were calculated.The excess thermodynamic properties were correlated with the Redlich-Kister polynomial equation. The experimental excess molar volumes values have been also used to test the applicability of the Prigogine-Flory-Patterson theory and the results were analyzed in terms of molecular interactions between the components of the mixture.Discussions concerning the experimental and calculated results in relation to the molecular interactions and structural effects between components of mixtures are presented.In the dilute range, at (0 to 0.3) diol mole fractions, the characteristic behavior of the excess and partial molar quantities was related to the structural changes in the mixtures as observed by neutron scattering.

Experimental and theoretical studies of volumetric and viscous properties of n-tetradecane with isomeric pentanols

In this research, we present the experimental measurements of physical properties of two binary liquid mixtures of n-tetradecane with 1-pentanol and 2-pentanol. Density and viscosity were measured at temperatures from (283.15 to 333.15) K with10 K intervals, underatmospheric pressure. Flash point and freezing point were measured over the entire composition range. Excess molar volume, deviation viscosity and excess Gibbs energy of activation of viscous flowof mixtures were calculated and fitted by Redlich-Kister equation. The excess molar volumes are positives, the viscosity deviations and excess Gibbs free energy are negatives over the entire composition range. Experimental excess molar volume was analyzed using Prigogine-Flory-Patterson (PFP) theory. Eyring_NRTL,Katti, Grunberg, Lobe, Heric, and McAllistercorrelations were used to fit viscosity data. Excess Gibbs free energy data were correlated using NRTL and Heil models. Among of used models PFP, Eyring_NRTL, Lobe, NRTL and Heil models gave good agreement with experimental data. All these results provide important information about thermophysical properties of hydrocarbon jet fuelwith green fuel as additives. Finally, the biojet formed by mixing the biomolecule (1-pentanol or 2-pentanol) with n-paraffin (n-tetradecane) can ameliorate the energetic efficacy and reduce dioxide of carbon emission.

Study of molecular interaction of Ethyl propionate with fossil fuels from 298.15 to 323.15 K temperatures

This paper presents the observational report of the authors on measured density (ρ), speed of sound (u) of pure liquids of Ethyl propionate (EP), and various renewable oxygenated fossil fuels (1,2-, 1,3- and 1,4-butanediols) and their mixtures at various temperatures (298.15–323.15 K) at ambient pressure 0.1 MPa. With measured experimental data, various acoustic and excess properties such as excess molar volume (), excess isentropic compressibility (), excess molar isentropic compressibility (), excess speed of sound (uE ) and excess isobaric expansivity () have been calculated. The excess and acoustic parameters have been integrated with the Redlich-Kister polynomial smoothing equation. The partial molar quantities and excess partial molar quantities at infinite dilution have been computed with measured R-K polynomials. The experimental excess molar volume is compared with the help of PFP theory.

Selection and characterization of non-ideal ionic liquids mixtures to be used in CO2 capture

Due to the costs involved, the capture of CO2 in post-combustion is not currently seen as economically viable. Aiming at changing the perception of post-combustion CO2 from a costly and non-profitable process to a valuable commodity and fostering the development of the next-generation of technologies, novel solvents and their mixtures have been investigated. In this work, mixtures of non-volatile ionic liquids were screened by COSMO-RS aiming to find mixtures with positive excess volumes that could present an increased CO2 capture by physical sorption. The most promising mixtures identified by COSMO-RS, [C4C1im][DMP] or [C4C1im][NTf2] + carboxylate-based protic ILs were characterized through the measurement of their thermophysical properties, namely density and viscosity. Both properties were measured for pure ILs and their binary mixtures at different temperatures and compositions. The temperature dependence of density of pure ILs was described using the Gardas and Coutinho model while viscosity was accurately described using the Vogel−Tammann−Fulcher equation. The Redlich-Kister equation was used to predict the excess molar volumes and the non-ideality of the mixtures’ viscosity was assessed using the Grunberg and Nissan mixing law. The excess molar volumes for mixtures containing [C4C1im][DMP] show large positive values all over the range of compositions and temperatures, making them good candidates for CO2 capture. To the best of our knowledge, the excess molar volumes obtained in this work were the highest reported so far. COSMO-RS was able to correctly predict the trend of the experimental excess molar volumes for these mixtures. Regarding viscosity, mixtures of [C4C1im][DMP] with the carboxylate-based protic ILs led to the desired viscosity decrease compared to the pure aprotic IL, and large deviations from ideality were observed. The mixing of ILs is thus an efficient way to fine-tune the properties, in this case decreasing the viscosity while increasing the sorption capacity.

Comments on “Reply to comments on study of density, dynamic viscosity, excess property and intermolecular interplay studies for 1,4-butanediol + dimethyl sulfoxide binary mixture”

A polemic is given regarding the volumetric properties reported in the authors' reply to an earlier commentary. The recalculated partial molar volumes of the individual mixture components, given in the authors' reply, are found to be thermodynamically inconsistent with the experimental excess molar volumes.

Thermodynamic study of interactions between 1-alkanol and butanone

To obtain the new perspectives on the molecular interactions in the binary systems of butanone and a homologous series of 1-alkanol from 1-pentanol up to 1-decanol, these mixtures were studied using the Kirkwood–Buff (KB) formalism and preferential solvation analysis. The results were confirmed using the experimental excess molar volumes. KB integralsGij, the excess or deficit numberΔnij, and solvation coefficients δijare reported here. Analysis of obtained data regarding the KB formalism and preferential solvation reveals that interactions strength in mixtures depends on the butanone concentration and size of 1-alkanol. Also, interactions between similar molecules are remarkable and become stronger as the length of the alcohol increases. Furthermore, mixtures structure was studied using the concentration-concentration structure factor, SCC(0). Results from application of this parameter show that the homocoordination occurs in solutions. Steric effects lead to the stronger orientations in the mentioned mixtures.

Investigation of molecular interactions in binary liquid mixture: Measurements and correlation through thermo physicochemical study

Density (ρ)/acoustic speed (u) of sound have been experimentally measured over the complete mole fraction on (dimethyl carbonate + diisopropyl ether) mixture at T = (308.15/313.15/318.15) K and atmospheric pressure. Investigational data have been used to gauge excess molar volume /partial molar volume/excess partial molar volume/excess values of intermolecular free length/isentropic compressibility/acoustic impedance/isobaric thermal expansion coefficient/isothermal compressibility/surface tension. Extended Langmuir model pertinent to surface tension was applied to check the depth of penetration of molecular interactions between molecules. The excess values were fitted to Redlich-Kister equation and subsequently standard deviations are evaluated from coefficients. The departures of computed excess properties were explored in terms of molecular interactions. Experimental excess molar volume in the existing adventure was correlated by Prigogine–Flory–Patterson (PFP) theory/Soave-Redlich-Kwong (SRK) CEoS/Peng-Robinson (PR) CEoS at 308.15 K. Theoretical excess chemical potentials are computed and correlated by Margules/Porter/Wilson and VanLaar models at 308.15 K. Furthermore, vital thermodynamical potential derivatives are worked out at all temperatures through physicochemical properties rather calorimetric experiments. Contemporary study also consists of estimation and correlation of cohesive energy ΔA, Van der Wall's constants (a, b), distance of closest approach (d) by Hartmann–Balizar and Ballou non-linear equations at all temperatures.

Commentary on “Studies on molar volume, dielectric properties and refractive indices of cyanex 923 + benzene/xylene at 300 K”

Redlich-Kister equation coefficients reported by Satpathy and coworkers [J. Mol. Liq. 222 (2016) 383–389] for binary benzene+cyanex 923 and xylene+cyanex 923 are found to be inconsistent with the graphs of the experimental excess molar volumes, excess molar polarizabilities and excess molar refractions. Values calculated from the reported Redlich-Kister equation coefficients differ significantly from the measured experimental data.

Relevance of the thermodynamic ERAS model for liquid mixtures with components exhibiting a small degree of self-association

The thermodynamic extended real associated solution (ERAS) model is reviewed and modified to accommodate weakly associating components. ERAS is a theoretical scheme applied to binary liquid mixtures whereby certain physically meaningful parameters such as the association equilibrium constants, species reduced volume and energy terms may be determined by optimization against the experimental excess molar volumes and enthalpies. The implicit assumption used for any non-associating molecule B is to routinely set the hydrogen-bonding energy ΔhB*, reaction volume ΔvB* and association constants KB to zero. It is proven here that such assignments lead to singularities in the ERAS parameters that are featured in the excess state functions used. A series of optimizations using the results of conductor-like screening model for real solvents (COSMO-RS) on the excess enthalpy HE of dimethoxymethane in binary mixtures with a series of alcohols are determined, and the parameters ΔhB*, ΔhAB* (mixed enthalpy of reaction) and XAB (interaction parameter) are determined. It is shown that the stipulated range of XAB values from ERAS theory requires minor modification if the above assumptions are not made. The magnitude of the computed variables are shown to be physically reasonable. The Bondi group averaged estimates for si, the ratio of the van der Waals (vdW) surface area to the vdW volume for molecule i, are contrasted against the more specific and reliable derivations from quantum calculations when calculating the excess functions. The degree of correlation is improved using the latter si values. We conclude that the results of the optimizations indicate that the ERAS model can be extended even to weakly self-associating components previously considered impossible in especially engineering thermodynamical applications, with the above modifications and refinements.

Densities and viscosities for binary mixtures of n-heptane with alcohols at different temperatures

Densities (?) and viscosities (?) of the binary systems n-heptane with alcohols (ethanol, propan-1-ol and propan-2-ol) were measured at temperatures between 288.15 and 308.15 K and at atmospheric pressure, over the whole composition range. The excess values of molar volume (VE) and viscosity (?E) were calculated from experimental measurements. The excess functions of the binary systems were fitted to Redlich?Kister Equation. Comparison between experimental excess molar volume and the one calculated from Flory and Prigogine?Flory?Patterson theories, has also been done. The viscosity results were fitted to the equations of Grunberg?Nissan, Heric?Brewer, Jouyban?Acree and McAllister. Also, the activation energies of viscous flow have been obtained and their variations with compositions have been discussed.

Investigation of molecular interactions in binary mixtures (dichloromethane + aliphatic alcohols) at T = (298.15 to 308.15) K: Experimental, ERAS analyses and COSMO-RS predictions

Densities ρ, and ultrasonic velocities, u of binary mixtures of pure dichloromethane (DCM) with methanol (Me-OH), ethanol (Et-OH), propan-1-ol (Pr-OH) and butan-1-ol (Bu-OH) including those of their binary liquids were measured at (298.15, 303.15 and 308.15) K. From the experimental data the excess molar volume, VmE, deviation in isentropic compressibility, Δks, deviation in specific acoustic impedance, ΔZ, deviation in intermolecular free length, ΔLf, and deviation in ultrasonic velocity, Δu were calculated. The experimental excess molar volume values were correlated with theoretical values derived from extended real association solution model (ERAS). The σ-profile of dichloromethane and aliphatic alcohols were computed with conductor-like screening model (COSMO-RS) and are interpreted to show the possible interactions between the mixing components.

Structural and compositional effect on the acoustic and volumetric properties of ammonium based ionic liquids with water and N-methyl-2-pyrrolidone

Understanding the volumetric behavior of ionic liquids with molecular solvents is essential for the development of industrial applications. In the present work, attempts have been made to explore and understand the effect of various structurally different protic ionic liquids upon the volumetric and acoustic behavior, when mixed with polar protic solvent (water) and polar aprotic solvent (N-methyl-2-pyrrolidone). Density and speed of sound for ten binary mixture containing five protic ionic liquids namely, propylammonium formate, propylammonium acetate, 3-hydroxypropylammonium formate, 3-hydroxypropylammonium acetate and 3-hydroxypropylammonium trifluoroacetate have been investigated over the whole range of composition at temperature from (293.15 to 333.15) K and at atmospheric pressure. The experimental density and speed of sound data have been used to calculate coefficient of thermal expansion, isentropic compressibility and excess molar volume of studied binary mixtures. In most of the studied binary systems the excess molar volumes were found to be negative and the experimental excess molar volumes have been correlated with Redlich–Kister equation. The protic and aprotic nature of molecular solvents along with its shape and size found to affect the studied volumetric properties. Moreover, the effect of anionic chain length, functionalization of cationic side with hydroxyl group and temperature upon studied properties has also been discussed. The results were analyzed on the basis of ion–dipole interaction, interstitial packing and hydrogen bonding between ionic liquids and molecular solvents.

Physiсo-chemical properties of binary mixtures of aliphatic and aromatic solvents at 313 K on acoustical data

Density (ρ), viscosity (η), and ultrasonic velocity (U) of binary mixtures of aliphatic solvents like dimethylformamide (DMF) and dimethylsulfoxide (DMSO) with aromatic solvents viz. chlorobenzene (CB), bromobenzene (BB), and nitrobenzene (NB) have been determined at 313 K. These parameters were used to calculate the adiabatic compressibility (β), intermolecular free length (Lf), molar volume (Vm), and acoustic impedance (Z). From the experimental data excess molar volume (VmE), excess intermolecular free length (LfE)), excess adiabatic compressibility (βE), and excess acoustic impedance (ZE) have been computed. The excess values were correlated using Redlich–Kister polynomial equation to obtain their coefficients and standard deviations (σ).

Calculation of excess molar enthalpy of binary liquid mixtures at high pressures from experimental data at low pressures

A new approach for calculating the excess molar enthalpies of binary liquid mixtures at entire pressure range of interest based on the experimental excess molar enthalpy (HmE) data at low pressure, is proposed. The method is a simple thermodynamic relation combined with the modified Redlich-Kister equation and modified local composition model (NRTL and Wilson) in which the binary parameters were temperature and pressure dependent that are determined by using experimental excess molar volume (VmE) at different temperatures and pressures. The calculation has been carried out for seven binary systems which include light hydrocarbon-alcohol systems plus water-ethanol. A comparison of the calculated and experimental HmE at different temperatures and pressures of seven binary mixtures indicate that the models describe the excess molar enthalpies very well quantitatively.

Volumetric behavior of the ternary system (methyl tert-butyl ether + methylbenzene + butan-1-ol) and its binary sub-system (methyl tert-butyl ether + butan-1-ol) within the temperature range (298.15 to 328.15) K

Values of the density and speed of sound were measured for the ternary system (methyl tert-butyl ether+methylbenzene+butan-1-ol) within the temperature range (298.15 to 328.15)K at atmospheric pressure by a vibrating-tube densimeter DSA 5000. Two binary sub-systems were studied and published previously while the binary sub-system (methyl tert-butyl ether+butan-1-ol) is a new study in this work. Excess molar volume, adiabatic compressibility, and isobaric thermal expansivity were calculated from the experimental values of density and speed of sound. The excess quantities were correlated using the Redlich–Kister equation. The experimental excess molar volumes were analyzed by means of both the Extended Real Associated Solution (ERAS) model and the Peng–Robinson equation of state. The novelty of this work is the qualitative prediction of ternary excess molar volumes for the system containing auto-associative compound and two compounds that can hetero-associate. The combination of the ERAS model and Peng–Robinson equation of state could help to qualitatively estimate the real behavior of the studied systems because the experimental results lie between these two predictions.

Modeling of Excess Molar Volumes of [Difurylmethane + (Acetonitrile or Propionitrile or Benzonitrile)] Binary Mixtures Using the Prigogine – Flory – Patterson Theory

The recently reported experimental excess molar volume data for {difuryl methane + (acetonitrile or benzonitrile or propionitrile)} binary mixtures as a function of composition at T = 298.15 K under atmospheric pressure, have been used to test the applicability of Prigogine-Flory-Patterson theory. Analysis of each of the three contributions to the experimental excess molar volume vis. the interactional, the free volume and the characteristic pressure terms, show that the interactional and the free volume contributions were negative for all three {difuryl methane + (acetonitrile or benzonitrile or propionitrile)} binary mixtures. The characteristic pressure contribution was negative for {difuryl methane + (acetonitrile or propionitrile)} and positive for (difuryl methane + benzonitrile). The relatively large magnitude of the interactional contribution which arises from dipole-dipole interactions between difurylmethane and the nitrile molecule determined the overall experimental shape of the excess molar volume isotherms for {difuryl methane + (acetonitrile or benzonitrile or propionitrile)} binary mixtures. The correlation between the theoretical and experimental excess molar volumes data was satisfactory for each of the three binary systems.

Bulk properties of a liquid phase mixture {ethylene glycol+tert-butanol} in the temperature range 278.15–348.15 K and pressures of 0.1-100 MPa. I. Experimental results, excess and partial molar volumes

The densities ρ and coefficients of compressibility k = ΔV/V0 of a binary mixture {ethylene glycol (1) + tert-butanol (2)} in the temperature range of 278.15–323.15 K and pressures of 0.1–100 MPa over the entire range of compositions of liquid phase state are measured. Found that the coefficients of compressibility k of the mixture increase both with an increase in the concentration of tert-butanol and with a rise in temperature and pressure. The excess molar volumes of the mixture, apparent, partial molar volumes, and limiting partial molar volumes of the components are calculated. It is showed that the excess molar volumes of the mixture are negative and decrease when the pressure increases. The excess molar volumes are described by the Redlich-Kister equation. The partial molar volumes of ethylene glycol sharply decrease in the range of high concentrations of tert-butanol. The dependences of partial molar volumes of ethylene glycol are characterized by the presence of a region of temperature inversion. The “negative compressibility” of the limiting partial volumes of ethylene glycol is revealed.

Volumetric behaviour of the (2,2,4-trimethylpentane + methylbenzene + butan-1-ol) ternary system and its binary sub-systems within the temperature range (298.15–328.15) K

Densities and speeds of sound of the (2,2,4-trimethylpentane+methylbenzene+butan-1-ol) ternary system as well as all its binary sub-systems were measured at four temperatures, namely 298.15K, 308.15K, 318.15K, and 328.15K at atmospheric pressure by a vibrating-tube densimeter DSA5000. The binary (isooctane+toluene) system was studied previously. Excess quantities (molar volume, adiabatic compressibility, and isobaric thermal expansivity) of the mixtures studied were calculated from the experimental densities and speed of sounds. The excess molar volume data were correlated using the Redlich–Kister equation. Both the positive and S-shaped excess molar volume curves were found for the systems studied. The excess molar volumes versus concentration of binary systems differed in the shape and temperature dependence. The experimental binary data were compared with literature data. The experimental excess molar volumes were analyzed by means of the Extended Real Associated Solution (ERAS) model. The experimental data and the ERAS model can help to estimate real behaviour of the systems studied.

Volumetric behavior of the ternary system benzene-2-methoxy-2-methylbutane-2,2,4-trimethylpentane and all binary sub-systems at temperature range (298.15–318.15) K

Densities of ternary liquid mixtures composed of benzene, 2-methoxy-2-methylbutane (i.e. tert-amyl methyl ether, TAME), and 2,2,4-trimethylpentane (i.e. isooctane, 2,2,4-TMP) are measured at three temperatures 298.15K, 308.15K, and 318.15K at atmospheric pressure by a vibrating-tube densimeter as well as all its binary sub-systems. Excess molar volumes of the mixtures are calculated from the experimental densities and then correlated using the Redlich–Kister equation. The determination of its adjustable parameters is made by the method of least squares. For all studied systems, the positive deviations from ideal behavior are observed at all temperatures. The excess molar volume curves of binary systems differ in the shape and temperature dependence. The experimental binary data are compared with literature data and discussed. The ternary system mentioned above is measured newly. Moreover, the experimental excess molar volumes are compared to the calculation using Peng–Robinson equation with a corrected parameter. The novelty of this work is the prediction of ternary excess molar volumes from binary parameters in Peng–Robinson equation.