Search

Densities and transport properties (dynamic viscosity) of pure imidazolium ionic liquids 1-butyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium dicyanamide and their binary mixtures with water and ethanol were measured within the temperature range of 293.15—333.15 K. Obtained experimental data were used to calculate excess molar volume and viscosity deviation. For the chosen binary mixtures, variations of excess molar volume, partial molar volumes of mixture components and of the viscosity deviation with the binary mixture composition were correlated using the Redlich-Kister equation. In addition, variation of viscosity with the binary mixture composition and temperature was fitted using the Jouyban-Acree model. [ABSTRACT FROM AUTHOR]

Densities and viscosities of the binary systems dimethylsulfoxide with diethylene glycol and methyldiethanolamine were measured at temperatures ranging from 293.15 to 313.15 K, at atmospheric pressure and over the entire composition range. The experimental density data was correlated as a function of composition using Belda's and Herraez's equations, and as a function of temperature and composition using the models of Emmerling et al. and Gonzalez-Olmos-Iglesias. The viscosity results were fitted to the Grunberg-Nissan, Heric-Brewer, Wilson, Noda, and Ishida and Eyring-NRTL equations. The values of viscosity deviation ( Δ η ), excess molar volume (VE), partial molar volumes ( V 1 ¯ and V 2 ¯ ) and apparent molar volume ( V φ , 1 and V φ , 2 ) were determined. The excess functions of the binary systems were fitted to the polynomial equations. The values of thermodynamic functions of activation of viscous flow were calculated and discussed. [ABSTRACT FROM AUTHOR]

Densities and viscosities of binary mixtures for methyl tert-butyl ether (MTBE) with methanol and diisopropyl ether (DIPE) have been measured at temperatures of 308.15, 313.15 and 318.15 K and at atmospheric pressure over the entire composition range. The measured densities and viscosities were fitted using Jouyban-Acree model where mean relative deviation (MRD) lesser than 0.02% are obtained for both predictions. The excess molar volumes and the viscosity deviations are calculated from measured densities and viscosities. Redlich-Kister equation is then used to correlate excess molar volumes and viscosity deviations where good fits have been achieved. Negative excess molar volume and viscosity deviation have been obtained for binary mixture MTBE + methanol at all investigated temperatures which indicating the presence of chemical and structural interactions. However, lack of specific interactions has been observed for binary mixture MTBE + DIPE based on positive excess molar volume and small negative values of viscosity deviation. [ABSTRACT FROM AUTHOR]

The organic solution composed of N,N,N′,N′-tetraoctyldiglycolamide (TODGA) and n-dodecane is extensively studied for the removal of trivalent actinides from the high-level liquid waste arising from nuclear industry. Present work deals with the evaluation of density and viscosity of TODGA/n-dodecane as a function of absorbed gamma radiation dose, temperature and composition. In addition, volumetric and viscometric properties like excess molar volume, apparent molar volume, viscosity deviation, activation energy for the viscous flow, enthalpy and entropy changes of activation of this binary mixture were also estimated. Based on these derived thermodynamic properties, the inter-molecular interactions of this binary liquid solution were predicted. Redlich–Kister type equations were employed to correlate excess volume and viscosity deviation, and the coefficients of fourth degree polynomial that fitted well with the experimental data were estimated. Present study indicated the stable nature of hydrodynamic behaviour of TODGA/n-dodecane system with respect to physical properties up to 500 kGy of absorbed gamma radiation dose. [ABSTRACT FROM AUTHOR]

Mixtures of ethylene glycol with water are a prominent example of media with variable viscosity, and ethylene glycol molecules serve as a prototype of various polyols having multiple hydroxyl groups. The dynamic viscosity of ethylene glycol–water mixtures was measured by vibro-viscosimetry over entire range of mole fraction under atmospheric pressure and from 10 to 30 °C; the variation of the viscosity activation energy with ethylene glycol mole fraction was determined and is discussed. In the present work we propose a novel equation for modeling the concentration dependences of the activation energy and viscosity. The theory is based on the assumption that the nonlinear characteristics can be associated with some structural changes of the mixtures, and that the reaction kinetics can be applied to this breakdown. The Grunberg–Nissan parameter and viscosity deviations were calculated. The possible changes in the variety of complexes for different concentration ranges is discussed. Correlation between the activation energy and pre-exponential factor was made. Three concentration regions are determined, separated by ethylene glycol molar fractions x = 0.11 and 0.43, where the structure of the water/ethylene glycol complexes changes. [ABSTRACT FROM AUTHOR]

Densities and viscosities of the binary systems dimethylsulfoxide with diethylene glycol and methyldiethanolamine were measured at temperatures ranging from 293.15 to 313.15 K, at atmospheric pressure and over the entire composition range. The experimental density data was correlated as a function of composition using Belda’s and Herraez’s equations, and as a function of temperature and composition using the models of Emmerling et al. and Gonzalez-Olmos-Iglesias. The viscosity results were fitted to the Grunberg-Nissan, Heric-Brewer, Wilson, Noda, and Ishida and Eyring-NRTL equations. The values of viscosity deviation (Δη), excess molar volume (VE), partial molar volumes (V1¯ and V2¯) and apparent molar volume (Vφ,1 and Vφ,2) were determined. The excess functions of the binary systems were fitted to the polynomial equations. The values of thermodynamic functions of activation of viscous flow were calculated and discussed.

[Display omitted] • Viscosities for Ethyl lactate + Glycols systems were measured. • Excess functions and Thermodynamic parameters of activation for viscous flow of binary mixtures were calculated. • Theoretical modeling of viscosity with various predictive and correlative approaches was done. • The intermolecular interactions in terms of Graph theory and Density functional theory were analysed. Polyethylene glycol and its oligomers are potential hydrogen bond donors that act as a green, effective, non-toxic, non-corrosive and recyclable molecular component for extractive desulfurization of liquid fuels and variety of other applications. The aim of this investigation is to explore the molecular interactions via variations in viscosity that occur on mixing these glycols with green solvent ethyl lactate. Dynamic viscosities (η) for pure solvents and binary mixtures of ethyl lactate and glycols oligomers (mono/di/tri/tetra-ethylene glycol) were measured at varying temperatures T/(K) = (298.15–313.15; with an interval of 5). Viscosity deviations (Δ η) along with excess thermodynamic parameters of activation for viscous flow as Gibbs free energy (Δ G ∗ E) , Enthalpy (Δ H ∗ E) and Entropy (Δ S ∗ E) were derived from experimental data. The Δ η and Δ G ∗ E values were further correlated using Redlich-Kister polynomial expression. The experimentally obtained viscosity values were compared with 10 generalised literature models (Arrhenius, Kendall, Kendall-Monroe, Grunberg-Nissan, Hind, Katti-Chaudhri, Heric, McAllister three-body, McAllister four-body and Jouyban-Acree models). The average standard deviation percentages (ASD %) were calculated for all the models to compare the quality of correlation with experimental data. The minimal ASD % for McAllister four-body and Jouyban-Acree models in the working systems indicate that the multiparameter relations have the best capability of reproducing the experimental values. The temperature induced variations were also discussed together with molecular interactions. Further, quantum mechanical density-functional theory and graph theoretical approaches were used to explore the extent of interactions among the components. [ABSTRACT FROM AUTHOR]

Highlights • The binary mixtures of [C 2 mmim][NTf 2 ]/[C 4 mmim][NTf 2 ] + DMC/DEC were prepared. • The density and dynamic viscosity of the binary mixtures were measured. • The excess molar volumes and viscosity deviations were calculated. • The properties were discussed with the extension of the alkyl chain of the cation. Abstract Two hydrophobic ionic liquids (ILs) 1-alkyl-2, 3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C 2 mmim][NTf 2 ] and [C 4 mmim][NTf 2 ]) were synthesized. The binary mixtures of the two ILs were prepared with dimethyl carbonate (DMC) or diethyl carbonate (DEC) over the entire mole fraction range, respectively. The density and viscosity of the binary mixtures were investigated at temperature ranging from 293.15 to 328.15 K. The excess molar volumes and viscosity deviations were calculated for the four binary mixtures. The effects of the extension of the alkyl chain of the cation on the above properties are discussed. The Redlich-Kister equation was used for the fitting of the excess molar volumes and viscosity deviations versus mole fraction. The thermal expansion coefficients of the systems were obtained according to the density. [ABSTRACT FROM AUTHOR]

Densities and viscosities of binary liquid mixtures of propyl propanoate + heptane and propyl propanoate + octane at temperatures of 278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15 K have been measured at atmospheric pressure over the entire range of composition. Using these experimental data, the excess molar volumes and the viscosity deviation have been calculated. The experimental data of density and viscosity at different investigated temperatures were mathematically represented by the Jouyban-Acree model. The mean relative deviation (MRD) was used as an error criterion, and the MRD values for data correlation of density and viscosity at different investigated temperatures are less than 0.03% and 0.50%, respectively. Excess molar volumes and viscosity deviations were correlated with Redlich-Kister equation. The calculated data point out the absence of specific interactions between the molecules of different components, which would be slightly weaker compared to the interactions in the pure components. [ABSTRACT FROM AUTHOR]

[Display omitted] • Viscometric properties of binary mixtures have been summarized. • Theoretical modeling of viscosity with various empirical and semi-empirical equations for the binary mixtures. • Experimentally obtained viscosity deviation was correlated by Graph theory. • Standard deviation percentage were computed to determine the quality of theories and models. Viscometric properties provide a deep and meaningful insight of the various interactions taking place in binary liquid mixtures. Recently, bio-based solvents have been either employed directly as green solvents or as a key component for the production of new solvent systems that are potentially less toxic and more bio-compatible. In this paper, we report experimental values of dynamic viscosity (η) for binary systems of bio-based solvent (gamma-valerolactone) with 2-alkoxyethanols at different temperatures (298.15–313.15 K; interval, 5 K), covering the whole composition range under atmospheric pressure of 0.1 MPa. On the experimental basis, kinematic viscosity (ν) , viscosity deviation (Δ η) and excess Gibbs free energy of activation for viscous flow (Δ G ∗ E) have been calculated. The derived properties, Δ η and Δ G ∗ E were fitted to Redlich-Kister polynomial equation to obtain binary adjustable parameters and standard deviations between experimental and estimated values. Further, the viscosity-composition data have been correlated with various approaches including no adjustable parameter (Bingham, Arrhenius, Kendall and Kendall-Monroe), one adjustable parameter, (Grunberg − Nissan, Hind et al. and Katti-Chaudhri), two adjustable parameter (McAllister three-body and Heric-Brewer) and three adjustable parameter (McAllister four-body and Jouyban-Acree) relations. Moreover, for all the predicted viscosity values, the standard deviation percentages (σ %) were calculated to compare the quality of correlations with experimental data. Furthermore, the Graph theory was employed to correlate experimental Δ η values and to analyse the patterns of molecular aggregation in the studied mixtures. The DFT calculations were also performed in the support of graph theory. The observed Δ η data suggests that the dissociation of self-associated structures of pure components is more dominating factor than hetero-association for all the studied binaries. [ABSTRACT FROM AUTHOR]

Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental values of density and viscosity. The mixture viscosities were correlated by several semi-empirical approaches like Hind, Choudhary–Katti, Grunberg–Nissan, Tamura and Kurata, McAllister three and four body model equations. A graphical representation of excess molar volumes and deviation in isentropic compressibility shows positive nature whereas deviation in viscosity shows negative nature at both temperatures for all four binary liquid mixtures. Positive values of excess molar volumes show that volume expansion is taking place causing rupture of H-bonds in self associated alcohols. The results were discussed in terms of molecular interactions prevailing in the mixtures.

Prigogine-Flory-Patterson (P-F-P) theory was applied for the correlation the experimental data of excess molar volume for the binary liquid mixture of DBSA-Acetone at the temperature range of (293.15-303.15 K). The three contribution terms (pressure, interaction and free volume) in the P-F-P equation were compared with the total effect of P-F-P equation. A positive excess molar volume were obtained at all the range of mole fraction and at all the temperatures. The maximum value of excess molar volume was positioned at the 0.4 mole fraction. Eyring-Flory- Huggins theory was found useful in the estimation of the viscosity deviation variation with mole fraction at the same temperature range. A negative deviation was found in the viscosity for all the range of temperature and mole fraction. The maximum deviation in the viscosity was found at the mole fraction of 0.4. The increase in the negative deviation values with temperature was interpreted as a result of the decrease in the attractive forces between the like molecules. [ABSTRACT FROM AUTHOR]

Densities, ρ, viscosities, η, and refractive indices, n , for 1-hexyl-3-methyl imidazolium chloride ([hmim]Cl) (IL), 1-pentanol, and ethylene glycol (EG), and for the binary mixtures { x [hmim]Cl + x 1-pentanol} and { x [hmim]Cl + x EG} were measured over the entire composition range at temperatures (293.15-333.15) K and ambient pressure. The excess molar volumes, $$ V_{\text{m}}^{\text{E}} $$ , and viscosity deviations, Δ η, for the binary mixtures were calculated from the experimental data. The $$ V_{\text{m}}^{\text{E}} $$ values of { x [hmim]Cl + x 1-pentanol} mixtures are negative over the entire composition range at all temperatures, and increase with increasing temperature in the alcohol rich region and decrease with increasing temperature in the IL rich range. The $$ V_{\text{m}}^{\text{E}} $$ values of { x [hmim]Cl + x EG} mixture are positive in the alcohol rich range and negative in the IL rich range at all temperatures, and decrease with increasing temperature. Viscosity deviations of both mixtures are negative over the entire composition range at all temperatures and decrease with increasing temperature. The excess molar properties were correlated by Redlich-Kister equation, and the excess molar volumes were correlated using the PFP model. The fitting parameters and standard deviations were determined. [ABSTRACT FROM AUTHOR]

Experimental densities and viscosities for the binary mixtures of polyoxymethylene dimethyl ethers with different CH 2 O chain length n = 2, 3, 4 were measured over a temperature range of 288.15 K–313.15 K and at the atmospheric pressure of 0.1 MPa. It is found that the order of densities and viscosities for pure components is PODE 2 < PODE 3 < PODE 4 at the same temperature. Meanwhile, for binary mixtures (PODE 2 -PODE 3 , PODE 2 -PODE 4 , PODE 3 -PODE 4 ), the densities and viscosities decreased with the increase of mole fraction of light component. On the basis of experimental data, the excess molar volumes and the viscosity deviations for the binary mixtures were calculated and correlated by the Redlich-Kister equation, while the excess Gibbs energy of activation for binary mixtures (PODE 2 -PODE 3 , PODE 2 -PODE 4 , PODE 3 -PODE 4 ) were also calculated and correlated. The results indicated that the difference of the CH 2 O chain length has a significant influence on the densities and viscosities of binary mixtures of polyoxymethylene dimethyl ethers. [ABSTRACT FROM AUTHOR]

The thermophysical properties, densities, ρ, speeds of sound, u and dynamic viscosities, η of pure ionic liquid, 1-ethyl-3-methylimidazolium ethylsulfate, ([EMIM][ES]), and solvents 1-butanol, methanol and of their binary and ternary mixtures have been measured experimentally at a temperature range from (298.15–323.15) K, with an interval of 5 K and at pressure 0.1 MPa by using Anton Paar vibrating tube density and sound velocity meter DSA 5000M and Lovis microviscometer 2000M. The excess molar volumes, V E , isentropic compressibilities, κ s , molar isentropic compressibilities, К s , m , excess molar isentropic compressibility, К s , m E , and viscosity deviations Δη have been calculated using the experimental ρ, u and η data at the same temperature range and pressure for [EMIM][ES] + 1-butanol/methanol binary systems and the V E , κ s , excess isentropic compressibility, κ s E and Δη for ternary [EMIM][ES] + 1-butanol + methanol system. The V E , κ s E , К s , m E and Δη data for the studied binary/ternary systems have been fitted to Redlich-Kister equation. The variations in V E , κ s E , К s , m E and Δη values with changes in composition and temperature have been discussed in terms of hydrogen bonding, ion–dipole interactions and structural effects on mixing of ILs and solvents. [ABSTRACT FROM AUTHOR]

This work reports density (ρ) and viscosity (η) data for binary system of polyethylene glycol 200 (PEG) and N -methyl-2-pyrrolidone (NMP) over the whole concentration range, at 288.15, 293.15, 298.15, 303.15, and 308.15 K as a function of composition at atmospheric pressure. From the experimental density and viscosity data, excess molar volume (V m E ), viscosity deviation (Δη) and the excess Gibbs free energies of activation for viscous flow (ΔG* E ) were calculated, and the results were fitted to a Redlich– Kister equation to obtain the coefficients and estimate the standard deviations between the experimental and calculated quantities. Based on kinematic viscosity ( ϑ ) data, enthalpy of activation for viscous flow (ΔH*), entropy of activation for viscous flow (ΔS*), and Gibbs energies of activation for viscous flow (ΔG*) were also calculated. In addition, the interactions between the unlike molecules of the PEG and NMP which were supported by FTIR spectra for the binary system of PEG and NMP were studied. [ABSTRACT FROM AUTHOR]

• ρ and η of pp + 2propanol, 2butanol, 2pentanol, or 2hexanol mixtures measured at all × range and T = (293.15 to 323.15) K. • The V m E values were calculated from experimental densities and correlated by Redlich-Kister equation. • The Δ η values were calculated from experimental viscosities and correlated by Redlich-Kister equation. • The excess molar volumes were correlated by using the PFP model. In the present work, the density and viscosity of binary mixtures of propiophenone (PP) + 2-propanol, PP + 2-butanol, PP + 2-pentanol, or PP + 2-hehanol were measured over all composition range and in the temperature range of 293.15 to 323.15 K at ambient pressure (0.1 MPa). Using the experimental data of density and viscosity, the excess molar volume and viscosity deviation were calculated and correlated by applying the Redlich-Kister equation. The results show that the excess molar volume of all mixtures is negative over the entire composition range at all temperatures and become more negative with increasing temperature. Also, the viscosity deviation of all mixtures is negative over the whole composition range at all temperatures and become less negative with increasing temperature. The excess molar volumes of mixtures were correlated by using Prigogine-Flory-Patterson (PFP) theory and the agreement between the calculated values with experimental data is good. [ABSTRACT FROM AUTHOR]

Densities, ρ, and viscosities, η, of pure isobutanol, 1-amino-2-propanol, and 1-propanol, along with their binary mixtures of { x isobutanol + x 1-propanol}, { x 1-amino-2-propanol + x 1-propanol}, and { x 1-amino-2-propanol + x isobutanol} were measured over the entire composition range and at temperatures (293.15-333.15) K at ambient pressure (81.5 kPa). Excess molar properties such as the excess molar volume, V , partial molar volumes, $$ \bar{V}_{1} $$ and $$ \bar{V}_{2} $$ , excess partial molar volumes, $$ \bar{V}_{1}^{\text{E}} $$ and $$ \bar{V}_{2}^{\text{E}} $$ , thermal expansion coefficient, α, excess thermal expansion coefficient, α , viscosity deviation, Δ η, and the excess Gibbs energy of activation, ∆ G , for the binary mixtures were calculated from the experimental values of densities and viscosities. The excess values of the binary mixtures are negative in the entire composition range and at all temperatures, and increase with increasing temperature. Viscosity deviations, Δ η, are negative over the entire composition range and decrease with increasing temperature. The viscosities of the mixtures were correlated by the models of McAllister, Heric, Hind, Katti, and Nissan. The obtained data were correlated by Redlich-Kister equation and the fitting parameters and standard deviations were determined. [ABSTRACT FROM AUTHOR]

Densities, speeds of sound and viscosities of 1-butyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide + methanol/dimethylsulfoxide mixtures have been measured experimentally over the entire composition range and at six temperatures, 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15 K, under 0.1 MPa pressure using Anton Paar density and sound velocity meter DSA 5000 M and Lovis microviscometer 2000M. From these experimental data, the excess molar volumes, V E , isentropic compressibility deviations, ∆ κ s and the viscosity deviations, ∆ η have been evaluated. The computed data have been adequately fitted to the Redlich–Kister polynomial equation. The measured and computed data have been interpreted in terms of ion–dipole interactions and structural effects between like and unlike molecules upon mixing. The V E results have been correlated to the Prigogine–Flory–Patterson (PFP) theory. The experimental and PFP correlated values are quite close to each other. [ABSTRACT FROM AUTHOR]

Densities and viscosities for the four binary liquid mixtures of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate with hexane-1-ol at temperatures 303.15 and 313.15 K and at atmospheric pressure were measured over the entire composition range. These values were used to calculate excess molar volumes and deviation in viscosities which were fitted to Redlich–Kister polynomial equation. Recently proposed Jouyban Acree model was also used to correlate the experimental values of density and viscosity. The mixture viscosities were correlated by several semi-empirical approaches like Hind, Choudhary–Katti, Grunberg–Nissan, Tamura and Kurata, McAllister three and four body model equations. A graphical representation of excess molar volumes and deviation in isentropic compressibility shows positive nature whereas deviation in viscosity shows negative nature at both temperatures for all four binary liquid mixtures. Positive values of excess molar volumes show that volume expansion is taking place causing rupture of H-bonds in self associated alcohols. The results were discussed in terms of molecular interactions prevailing in the mixtures. [ABSTRACT FROM AUTHOR]

Abstract: Viscosities of the systems of tert-butanol (TB)+n-butylamine (NBA), TB+di-n-butylamine (DBA) and TB+tri-n-butylamine (TBA) were determined at the temperatures ranging from 303.l5 to 323.15K within the composition range 0≤x2 ≤1, where x2 is the mole fraction of TB. The viscosity, η increases slowly up to x2 ~0.7, beyond which the values increase sharply until that of pure TB is reached. In all systems, deviations in viscosity, Δη show negative values throughout the whole range of composition with minima in the TB-rich region. The magnitudes of the negative values of Δη at the minimum are in the order TB+TBA>TB+DBA>TB+NBA. The negative Δη has been accounted for dispersive force. [Copyright &y& Elsevier]

Densities ( ρ) and viscosities ( η) of ternary mixtures of 2-methylbutan-2-ol (1) + trichloroethylene (2) + acetonitrile (3) and the related binary mixtures of {2-methylbutan-2-ol (1) + trichloroethylene (2)}, {2-methylbutan-2-ol (1) + acetonitrile (3)}, and {trichloroethylene (2) + acetonitrile (3)} have been measured over the whole composition range at 298.15 K and at ambient pressure (81.5 kPa). Excess molar volumes $$ V_{\text{m}}^{\text{E}} $$ , viscosity deviations Δ η, and excess Gibbs energies of activation Δ G were derived from the experimental data. The binary and ternary data of $$ V_{\text{m}}^{\text{E}} $$ , Δ η, and Δ G for the binary and ternary mixtures were correlated as functions of the mole fraction by using the Redlich-Kister and the Cibulka equations. Kinematic viscosities of the binary mixtures were correlated by means of several semi-empirical equations to determine the fitting parameters and the SDs. The experimental results are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures. [ABSTRACT FROM AUTHOR]

In this work, densities and viscosities for the binary mixtures of 1-octyl-3-methylimidazolium tetrafluoroborate, [Cmim][BF], with butanone, methyl acetate, ethyl acetate, propyl acetate and butyl acetate have been determined at 298.15 K. These data were used to calculate the excess molar volumes $$ V_{m}^{\text{E}} $$ and the viscosity deviations (ln η) for the mixtures. It is shown that values of $$ V_{m}^{\text{E}} $$ are negative, while those of (ln η) are positive in the whole concentration range. The $$ V_{m}^{\text{E}} $$ values show their minimum at the composition of x ≈ 0.3, and the (ln η) values exhibit a maximum at the same mole fraction. For the binary systems, the absolute values of $$ V_{m}^{\text{E}} $$ decrease in the order: butanone > methyl acetate > ethyl acetate > propyl acetate > butyl acetate, whereas those of (ln η) decrease in the order: methyl acetate > ethyl acetate > propyl acetate > butyl acetate > butanone. The results are discussed in terms of the ion-dipole interactions between cations of the ionic liquid and the organic molecules and hydrogen bonding interactions between anions of the ionic liquid and the organic compounds. [ABSTRACT FROM AUTHOR]

Abstract: In this work, densities, ρ, and viscosities, η, of pure 1-hexyl-3-methylimidazoliumtetrafluoro borate {[C6mim][BF4]}, 3-amino-1-propanol (AP), and isobutanol, along with their binary mixtures of {x 1[C6mim][BF4]+ x 2AP} and {x 1[C6mim][BF4]+ x 2isobutanol} were measured over entire composition range at ambient pressure (81.5kPa) and in the temperature range of (303.15 to 338.15)K. The excess molar volume, , thermal expansion coefficient, α, and its excess value, αE , isothermal coefficient of excess molar enthalpy, , and viscosity deviation, Δη, for both of the mixtures were calculated from the experimental values of densities and viscosities. The values of for binary mixture of {x 1[C6mim][BF4]+ x 2AP} shows a S-shaped dependence on composition with positive values in the [C6mim][BF4] rich-region and negative values at the opposite extreme, and increase with increasing temperature. This quantity is negative for binary mixture of {x 1[C6mim][BF4]+ x 2isobutanol} in the entire composition range and increases with increasing temperature. Viscosity deviations, Δη, are negative over the entire composition range and decrease with increasing temperature for both of the mixtures. These data were correlated by Treszczanowiczb–Benson and Redlich–Kister equations, and the fitting parameters and standard deviations were determined. The Prigogine–Flory–Patterson theory has been used to correlate the excess molar volumes of the mixtures. [Copyright &y& Elsevier]

Experimental densities ρ, viscosities η, and refractive indices n of the ternary mixtures consisting of 2-methyltetrahydrofuran + chlorobenzene + cyclopentanone and constituted binary mixtures were measured at T = 298.15 K for the liquid region and at ambient pressure for the whole composition range. Excess molar volumes $$V_{\text{m}}^{\text{E}}$$, deviations in the viscosity Δ η, and deviations in the refractive index Δ n from the mole fraction average for the mixtures were derived from the experimental data. The excess partial molar volumes $$V_{{\text{m}},i}^{\text{E}}$$ were also calculated. The binary and ternary data of $$V_{\text{m}}^{\text{E}}$$, Δ η, and Δ n were correlated as a function of the mole fraction by using the Redlich-Kister and the Cibulka equations, respectively. McAllister's three-body interaction model is used for correlating the kinematic viscosity of binary mixtures with the mole fraction. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Densities and viscosities were determined for binary mixtures containing the protic ionic liquid bis(2-hydroxyethyl)methylammonium formate [BHEMF] with methanol, ethanol, and 1-propanol at four different temperatures (293.15, 303.15, 313.15, and 323.15 K) and atmospheric pressure. Excess molar volume and viscosity deviations for the binary system were calculated. The calculated results were fitted to a Redlich-Kister equation to obtain the coefficients and estimate the standard deviations between the experimental and calculated quantities. The negative values of excess volume molar for these mixtures indicate that ion-dipole interactions and packing between ionic liquids and alcohols are present. The values of viscosity deviation are also negative over the whole composition range, and their values become less negative as the temperature increases. [ABSTRACT FROM AUTHOR]

Density, viscosity, speed of sound and refractive index of the binary mixture of 2-methoxyethanol (2-ME) + diethylether, 2-ME + dichloromethane (DCM) and diethyl ether + DCM and the ternary mixture of 2-ME + diethylether + DCM have been measured at 298.15 K and atmospheric pressure over the entire composition range. These results are used to calculate excess molar volume (VE), viscosity deviation (Δη), deviation in isentropic compressibility (ΔKS), excess Gibbs free energy of activation (ΔG*E) and excess molar refraction (ΔR) for the above systems. The calculated quantities are further fitted to the Redlich-Kister equation to estimate the binary fitting parameters and root mean square deviations from the regression lines. These excess properties have been used to discuss the presence of significant interactions between the component molecules in the binary and ternary mixtures. The excess or deviation properties were found to be either negative or positive depending on the molecular interactions and the nature of liquid mixtures and have been discussed in terms of molecular interactions and structural changes. [ABSTRACT FROM AUTHOR]

Abstract: The densities, viscosities and ultrasonic velocities for glycylglycine–NiCl2 in aqueous ethanol mixtures have been studied in the temperature range 288.15–318.15K. The excess molar volumes, viscosity deviations and changes in isentropic compressibility for the binary mixtures have been calculated and discussed in terms of hydrogen bonding and structure-breaking effect. The computed results are fitted to the Redlich–Kister polynomial. The results clearly indicate that there is a strong association in the mixtures studied. [Copyright &y& Elsevier]

Abstract: Densities and viscosities were measured for pure ionic liquid [C6mim][Br] (1-hexyl-3-methylimidazolium bromide) and the binary system (water+[C6mim][Br]) at 0.1MPa and in the (293.15 to 333.15)K range. The excess molar volume and viscosity deviation were calculated and correlated by Redlich–Kister polynomial expansions. The fitting parameters and the standard deviations were determined. [Copyright &y& Elsevier]

Densities and viscosities were measured for binary mixtures of isoamyl alcohol with 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol over the entire range of composition at 303.15 K, 313.15 K, and 323.15K and ultrasonic speeds and refractive indices at 303.15 K under atmospheric pressure. From the experimental values of density, viscosity, ultrasonic speed, and refractive index, the values of excess molar volume ( VE), viscosity deviations (Δ η), deviations in isentropic compressibility (Δ K S), and excess molar refraction (Δ R) have been calculated. The excess or deviation properties were found to be either negative or positive, depending on the molecular interactions and the nature of liquid mixtures. [ABSTRACT FROM AUTHOR]

Density, ρ, and viscosity, η, of binary mixtures of 2-methoxyethanol with methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol, and heptane-1-ol are determined over the entire range of composition at 298.15, 308.15, and 318.15 K. The speed of sound, u, of the above binary mixtures has been measured at 298.15 K. The experimental values of densities, viscosities, and speeds of sound are used to calculate the excess molar volume VE, viscosity deviation Δη, excess isentropic compressibility [image omitted], excess acoustic impedance ZE, and excess intermolecular free length [image omitted]. The viscosity data have been correlated by Grunberg and Nissan, Tamura-Kurata and Hind correlation equations. The VE, Δη, [image omitted], ZE, and [image omitted] are fitted to the Redlich-Kister equations. The results are discussed in terms of molecular interactions and structural effects. [ABSTRACT FROM AUTHOR]