首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Summary. Density (ρ) and viscosity (η) values of the binary mixtures of DMP + 1-pentanol, 1-butanol, and 1-propanol over the entire range of mole fraction at 298.15 and 303.15 K were measured in atmospheric pressure. The excess molar volume (V E), viscosity deviations (Δη), and excess Gibbs energy of activation for viscous flow (G*E) were calculated from the experimental measurements. These results were fitted to Redlich–Kister polynomial equation to estimate the binary interaction parameters. The viscosity data were correlated with equations of McAllister. The calculated functions have been used to explain the intermolecular interaction between the mixing components.  相似文献   

2.
Densities and viscosities of the binary mixtures of m-cresol with 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane and tetrachloroethylene were measured at 303.15, 313.15 and 323.15 K. The measured results are used to compute the excess volumes (VE), deviations in viscosity (Δη) and excess Gibbs energy for activation of flow (ΔGE). The excess volumes, deviations in viscosity, and Gibbs energies for activation of flow are fitted to a polynomial-type equation suggested by Scharlin et al. [J. Chem. Thermodyn. 34, 927 (2002)] and are discussed in general terms.  相似文献   

3.
Ultrasound velocity (u), density (ρ) and viscosity (η) measurements of benzaldehyde + ethylbenzene mixtures have been carried out at 303.15, 308.15, and 313.15 K. These values have been used to calculate the excess molar volume (V E), deviation in viscosity (δη), and deviation in isentropic compressibility (δβs), deviations in ultrasound velocity (δu), excess free volume (δV f), excess intermolecular free length (δL f) and excess Gibbs free energy of activation of viscous flow (δG E). McAllister’s three body interaction model is used for correlating kinematic viscosity of binary mixtures. The excess values were correlated using the Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. The thermophysical properties under the study were fit to the Jouyban-Acree model. The observed variation of these parameters helps in understanding the nature of interactions in these mixtures. Further, theoretical values of the ultrasound speed were evaluated using theories and empirical relations.  相似文献   

4.
The excess molar volumes, V mE, viscosity deviations, Δη, and excess Gibbs energies of activation, ΔG *E, of viscous flow have been investigated from density and viscosity measurements for two ternary mixtures, 1-butanol + triethylamine + cyclohexane and 1-pentanol + triethylamine + cyclohexane, and corresponding binaries at 303.15 K and atmospheric pressure over the entire range of composition. The empirical equations due to Redlich-Kister, Kohler, Rastogi et al., Jacob-Fitzner, Tsao-Smith, Lark et al., Heric-Brewer, and Singh et al. have been employed to correlate V mE, Δη and ΔG *E of the ternary mixtures with their corresponding binary parameters. The results are discussed in terms of the molecular interactions between the components of the mixture. Further, the Extended Real Associated Solution, ERAS, model has been applied to V mE for the present binary and ternary mixtures, and the results are compared with experimental data.  相似文献   

5.
Excess molar volumes (V E), viscosities, refractive index, and Gibbs energies were evaluated for binary biodiesel + benzene and toluene mixtures at 298.15 and 303.15 K. The excess molar volumes V E were determined from density, while the excess Gibbs free energy of activation G*E was calculated from viscosity deviation Δη. The excess molar volume (V E), viscosity deviation (Δη), and excess Gibbs energy of activation (G*E) were fitted to the Redlich-Kister polynomial equation to derive binary coefficients and estimate the standard deviations between the experimental data and calculation results. All mixtures showed positive V E values obviously caused by increased physical interactions between biodiesel and the organic solvents.  相似文献   

6.
In this work we used the experimental result for calculating the thermal expansion coefficients α, and their excess values α E , and isothermal coefficient of pressure excess molar enthalpy and comparison the obtain results with Flory theory of liquid mixtures for the binary mixtures {methanol, ethanol, 1-propanol and 2-butanol-chloroform} at 288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15 K. The excess thermal expansion coefficients α E and the isothermal coefficient of pressure excess molar enthalpy ((∂H mE/∂P) T,x for binary mixtures of {methanol and ethanol + chloroform} are S-shaped and for binary mixtures of {1-propanol and 2-butanol + chloroform} are positive over the mole fraction. The isothermal coefficient of pressure excess molar enthalpy (∂H mE/∂P) T,x , are negative over the mole fraction range for binary mixture of {1-propanol and 2-butanol + chloroform}. The calculated values by using the Flory theory of liquid mixtures show a good agreement between the theory and experimental.  相似文献   

7.
Excess molar volumes (V m E ) and viscosities (η) of the binary mixtures of 1,2-diethoxyethane with di-, tri- and tetrachloromethane have been measured at 298-15 K and atmospheric pressure over the entire mole fraction range. The deviations in viscosities (δlnη) and excess energies of activation (δG*E) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used to calculateV m E , and the results have been compared with experimental data. The Bloomfield and Dewan model has been used to calculate viscosity coefficients and these have also been compared with experimental data for the three mixtures. The results have been discussed in terms of dipole-dipole interactions between 1,2-diethoxyethane and chloroalkanes and their magnitudes decreasing with the dipole character of the molecules. A short comparative study with results for mixtures with polyethers and chloroalkanes is also described.  相似文献   

8.
The excess molar volumes (VE), excess surface tensions (σE), and deviations in molar refraction (RE) and isentropic compressibility (ksE) of binary mixtures of cyclohexanone with methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol have been determined over the entire composition range at 293.15 K. The results were fitted by the Redlich–Kister polynomial equation and the corresponding binary coefficients Ak have been derived. The standard deviations between the calculated and the experimental excess properties have been determined. The results provide information on the interactions of the molecules in the pure liquids as well as in the binary mixtures.  相似文献   

9.
Densities, viscosities and speeds of sound of binary mixtures of ethyl benzoate with cyclohexane, n-hexane, heptane and octane have been measured over the entire range of composition at (303.15, 308.15 and 313.15) K and at atmospheric pressure. From these experimental values, excess molar volume (V E), deviation in viscosity (Δη) and deviation in isentropic compressibility (ΔK s) have been calculated. The viscosities of binary mixtures were calculated theoretically from the pure component data by using various empirical and semi-empirical relations and the results compared with the experimental findings.  相似文献   

10.
Densities (ρ), viscosities (η) and speeds of sound (u) of the ternary mixture (1-heptanol + tetrachloroethylene + methylcyclohexane) and the corresponding binary mixtures (1-heptanol + tetrachloroethylene), (1-heptanol + methylcyclohexane) and (tetrachloroethylene + methylcyclohexane) at 298.15 K were measured over the whole composition range. The data obtained are used to calculate the excess molar volumes (V E), excess isobaric thermal expansivities (α E), viscosity deviations (Δη), excess Gibbs energies of activation of viscous flow (ΔG *E) and excess isentropic compressibilities (κ S E) of the binary and ternary mixtures. The data from the binary systems were fitted by the Redlich–Kister equation whereas the best correlation method for the ternary system was found using the Nagata equation. Viscosities, speeds of sound and isentropic compressibilities of the binary and ternary mixtures have been correlated by means of several empirical and semi-empirical equations. The best correlation method for viscosities of binary systems is found using the Iulan et al. equation and for the ternary system using the Heric and McAllister equations. The best correlation method for the speeds of sound and isentropic compressibilities of the binary system (1-heptanol + methylcyclohexane) is found using IMR (Van Deal ideal mixing relation) and for the binary system (tetrachloroethylene + methylcyclohexane) it is found using the NR (Nomoto relation) and for the binary system (1-heptanol + tetrachloroethylene) and the ternary system (1-heptanol + trichloroethylene + methylcyclohexane) it is obtained from the FLT (Jacobson free length theory).  相似文献   

11.
Viscosity η, and density ρ, of binary liquid mixtures of vinyl acetate or benzyl acetate with o-xylene, m-xylene, p-xylene and ethyl benzene have been determined at (303.15 and 313.15) K for the entire composition range. From the experimental values excess molar volume and deviations in viscosity have been calculated. These excess quantities were fitted to the Redlich-Kister polynomial equation. The viscosity data have been correlated using the Grunberg-Nissan, Tamura and Kurata, Auslander, and Jouyban-Acree models.  相似文献   

12.
Densities (ρ) at different temperatures from 303.15 to 318.15 K, speeds of sound (u) and viscosities (η) at 303.15 K were measured for the binary mixtures of cyclohexanol with 2-chlorotoluene, 3-chlorotoluene and 4-chlorotoluene over the entire range of composition. The excess volumes (VE) for the mixtures have been computed from the experimental density data. Further, the deviation in isentropic compressibilities (Δκs) and deviation in viscosities (Δη) for the binary mixtures have been calculated from the speed of sound and viscosity data, respectively. The VE values and Δκs values were positive and Δη data were negative for all the mixtures over the whole range of composition at the measured temperatures. The calculated excess functions VE, Δκs and Δη were fitted to Redlich–Kister equation. The excess functions have been discussed in terms of molecular interactions between component molecules of the binary mixtures.  相似文献   

13.
The viscosity deviation (Δη), the excess molar volume (V E) and the ultrasonic speed (u) have been investigated from viscosity (η) and density (ρ ) measurements of binary liquid mixtures of 1,2-dimethyoxyethane with methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol or octan-1-ol over the entire range of composition at 298.15 K. The excess volumes are negative over the entire range of composition for all of the mixtures with the exception of hexan-1-ol and octan-1-ol. The excess isentropic compressibilities (K S E) and viscosity deviations are negative for all of the mixtures. The magnitudes of the negative values of V E decrease with the number of carbon atoms of the alkan-1-ol. The trend of increasing K S E values with the chain length of the alkanol is similar to that observed in the case of V E. Graphs of V E, Δ η, K S E, Δ u, L f E and Z E against composition are presented as a basis for a qualitative discussion of the results.  相似文献   

14.
The data on excess volume (V E), density (ρ), viscosity (η) and speeds of sound (u) for the binary mixtures of tert-butylamine (TBA) + methyl acetate (MA), + ethyl acetate (EA), + butyl acetate (BA) and + isoamyl acetate (IAA) at 303.15 K were measured experimentally over the entire range of composition. Speeds of sound were evaluated using Jacobson’s free length theory (FLT) and Schaaffs’ collision factor theory (CFT). The viscosity data were analyzed on the basis of the corresponding states approach and the Grunberg and Nissan treatment. The experimental results for excess volume, deviation in isentropic compressibility and deviation in viscosity were discussed in terms of molecular interactions between unlike molecules. A Redlich-Kister type equation was used to fit the experimental data on excess volume, deviation in compressibility and deviation in viscosity.  相似文献   

15.
Abstract

The ultrasonic velocity, u, viscosity, η, and density, ρ of dimethylsulphoxide (DMSO), 1-butanol, 1-hexanol, 1-octanol, and of their binary mixtures, where DMSO is common component, have been measured at 303.15 K. From the experimental data, excess isentropic compressibility, K E s, excess intermolecular free length, LE f, excess velocity, u E, excess acoustic impedance, Z E, excess viscosity, ηE, excess free energy of activation of viscous flow, G?E, and excess rheochore, [R E] have been calculated. The behaviours of excess functions with composition of the mixtures suggest that the structure-breaking effect dominates over the interaction effect between the component molecules. Furthermore, the experimental values of u and η were fitted by empirical equations stating their dependence on composition of the mixtures. The experimental values of u have been compared with those calculated by using Nomoto and Van Dael relations.  相似文献   

16.
Densities (ρ), viscosities (η), and speeds of sound, (u) of the binary mixtures of 2-propanol with n-alkanes (n-hexane, n-octane, and n-decane) were measured over the entire composition range at 298.15 and 308.15 K and at atmospheric pressure. Using the experimental values of density, viscosity and speed of sound, the excess molar volumes (V E), viscosity deviations (Δη), deviations in speed of sound (Δu), isentropic compressibility (κ s), deviations in isentropic compressibility (Δκ s), and excess Gibbs energies of activation of viscous flow (ΔG* E) were calculated. These results were fitted to the Redlich–Kister type polynomial equation. The variations of these excess parameters with composition were discussed from the viewpoint of intermolecular interactions in these mixtures. The excess properties are found to be either positive or negative depending on the molecular interactions and the nature of liquid mixtures.  相似文献   

17.
Densities (ρ), speeds of sound (u), and isentropic compressibilities (k S) of binary mixtures of dimethyl sulfoxide (DMSO) with water, methanol, ethanol, 1-propanol, 2-propanol, acetone and cyclohexanone have been measured over the entire composition range at 293.15 and 313.15 K. The excess molar volumes (V E), the deviations in speed of sound (u E) and the deviations in isentropic compressibility (k S E) have been determined. The V E, u E and k S E values were fitted by the Redlich-Kister polynomial equation and the A k coefficients as well as the standard deviations (d) between the calculated and experimental values have been derived. The results obtained are discussed from the viewpoint of the existence of interactions between the components of the binary mixtures.  相似文献   

18.
The excess molar volume VE, shear viscosity deviation Δη and excess Gibbs energy of activation ΔGE of viscous flow have been investigated by using density (ρ) and shear viscosity (η) measurements for isobutyric acid + water (IBA+W) mixtures over the entire range of mole fractions at five different temperatures, both near and close to the critical temperature (2.055K ≤ (TTc)≤ 13.055K). The results were also fitted with the Redlich–Kister equation. This system exhibited very large negative values of VE and very large positive values of Δη due to increased hydrogen bonding interactions and correlation length between unlike molecules in the critical region and to very large differences between the molar volumes of the pure components at low temperatures. The activation parameters ΔH and ΔS have been also calculated and show that the critical region has an important effect on the volumetric properties.  相似文献   

19.
The molar excess enthalpies H m E of binary solvent mixtures of N-methylacetamide with methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and t-butanol have been measured with a flow microcalorimeter at 40°C. The excess enthalpies are negative for methanol and positive for the other alcohols over the whole composition range, except for t-butanol which exhibits a sigmoid curve with a deep minimum at low mole fractions of the amide. The values for the primary alcohols increase in the order methanol < ethanol < 1-propanol < 1-butanol. The partial molar excess enthalpies have also been evaluated. Intermolecular interactions in these mixtures are discussed through comparison of the results with those for the corresponding binary mixtures of N,N-dimethylacetamide.  相似文献   

20.
Abstract

New experimental data for excess volume of five binary mixtures are reported at 303.15 K. The mixtures contain 1,1,1-trichloroethane as common component and 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol as noncommon components. VE exhibits inversion in sign in all mixtures except that containing 1-pentanol. In this mixture VE is positive over the whole range of composition. The results have been interpreted in terms of the relative strength of structure breaking and structure making effects.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号