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 15 毫秒
1.
《Fluid Phase Equilibria》1998,145(1):115-128
Densities of the liquid mixtures (n-hexane+1-chlorobutane) and (1-butanol+n-hexane+1-chlorobutane) have been measured by the vibrating tube technique at 298.15 K and 313.15 K. With these densities, excess molar volumes were calculated. An extended version of the so-called ERAS model has been used for describing VE of the complete ternary system at 298.15 K. Qualitatively the ERAS-model gives an adequate representation of this system, being similar the shapes of both the experimental and the predicted curves.  相似文献   

2.
《Thermochimica Acta》2003,405(1):147-154
This paper reports measurements on excess thermodynamic properties for the ternary system: butyl butyrate+1-octanol+decane at the temperature 308.15 K and atmospheric pressure.The binary and ternary experimental data were correlated using the Redlich-Kister and Cibulka equation, respectively. Experimental values were compared with the predictions obtained by several contribution models and several empirical equations.  相似文献   

3.
Densities of the ternary system toluene + butyl acrylate + methyl methacrylate and its three binaries have been measured in the whole composition range, at 298.15 K and atmospheric pressure using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes are positive for the binary systems toluene + methyl methacrylate and butyl acrylate + methyl methacrylate and negative for the system toluene + butyl acrylate. The corresponding data were correlated with the Redlich–Kister equation and with a series of Legendre polynomials. Several empirical equations were used to correlate the ternary behavior from the excess molar volume data of their constituent binaries and were found equally good to fit the data. The best fit was based on a direct approach, without information on the component binary systems.  相似文献   

4.
5.
6.
《Fluid Phase Equilibria》2002,202(2):385-397
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.  相似文献   

7.
《Fluid Phase Equilibria》1998,152(2):283-298
The results of excess molar volumes for ternary mixture N,N-dimethylformamide (DMF)+1-propanol+water and for binary constituents, DMF+water, DMF+1-propanol and 1-propanol+water at 298.15 K are reported. Several empirical expressions were used to predict and correlate the ternary excess molar volumes from experimental results on the constituent binaries. A pseudo-binary mixture approach (PBMA) was used to analyze the system studied. The partial molar volumes of 1-propanol at infinite dilution in [fmDMF+(1−fm)water] mixed solvents at their several fixed composition fm were evaluated and correlated with the composition fm.  相似文献   

8.
Excess molar volumes VE at 298.15 K and atmospheric pressure for 1-propanol and 1-hexanol + butyl methyl ether, + dipropyl ether or + dibutyl ether with a vibrating-tube densimeter. The VE are negative over the whole mole-fraction range and nearly have been calculated from densities measured symmetrical for all the systems investigated. For each monoether, the VE decreases as the chain length of the 1-alcohol increases. For each 1-alcohol, the VE increases as the chain length of the symmetrical di-n-alkyl ethers increases. Moreover, for the butyl methyl ether (an asymmetrical monoether), the VE is more positive than of the immediately higher symmetrical dipropyl ether. These results, together with previously published excess molar enthalpies HE, suggest the formation of hydrogen bonds between the functional group (---OH) of the 1-alcohol and the (---O---) atoms of the monoethers.  相似文献   

9.
Densities and viscosities were determined for the n-pentanol-cumene-1,4-dioxane system at 298.15 K. From the experimental results, molar excess volumes and excess viscosities were calculated. Different expressions exist in the literature to predict these excess properties from the binary data. The empirical correlation of Cibulka is shown to be the best for this system.  相似文献   

10.
《Fluid Phase Equilibria》2003,211(1):61-73
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.  相似文献   

11.
Vapour pressures of methanol + piperidine at 298.15, 308.15, and 318.15 K were measured by a static method. Excess enthalpies and densities of the same mixtures at 298.15 K were also determined with an isothermal dilution calorimeter and a pyknometer. The excess functions were evaluated from these results; the values for mole fraction x = 0.5 at 298.15 K are: GE = ?834.1 Jmol?1, HE = ?3159.1 Jmol?1, TSE = ?2325.0 Jmol?1, VE = ?1.26 cm3mol?1.  相似文献   

12.
13.
Experimental density data of the binary mixtures of N-methyldiethanolamine + (2-aminoethyl)ethanolamine and the ternary mixtures of N-methyldiethanolamine + (2-aminoethyl)ethanolamine + water were reported at atmospheric pressure over the entire composition range at temperatures from 283.15 to 363.15 K. Density measurements were performed using an Anton Paar digital vibrating U-tube densimeter. Excess molar volumes were calculated from the experimental data and correlated as the Redlich-Kister equation for the binary mixtures, and as the Nagata-Tamura equation for the ternary mixtures. Several empirical models were applied to predict the excess molar volumes of ternary mixtures from the corresponding binary mixture values. It indicates that the best agreement with the experimental data was achieved by the Redlich-Kister, Kohler, and Jacob-Fitzner models.  相似文献   

14.
《Fluid Phase Equilibria》1998,153(2):293-315
Vapour–liquid equilibrium (VLE) for the ternary system ethanol (EtOH)+N,N-dimethylformamide (DMF)+cyclohexane (Cy) and for the relevant binary mixtures containing DMF have been determined at 298.15 K by headspace gas chromatographic analysis of the vapour phase directly withdrawn from an equilibrium apparatus. Measurements of liquid–liquid equilibria in both binary DMF+Cy and ternary mixtures have been also carried out. The binary VLE data have been described with different correlation equations. The capabilities of different models of either predicting or reproducing the ternary data have been compared. Excess Gibbs energies GE as well as activity coefficients γi of components have been obtained and briefly discussed. While EtOH+DMF behaves almost ideally with slightly negative GE-values, both EtOH+Cy and DMF+Cy exhibit large positive deviations. The GEs of the ternary system are positive with the exception of a narrow region in dilute Cy. The excess entropy and the temperature dependence of GE and γi have been calculated in the whole ternary domain from the known excess enthalpy and heat capacity. The predictions by different equations of the effect of temperature on the mutual solubilities of DMF and Cy as well as on the binodal curve of EtOH+DMF+Cy have been compared with experiment.  相似文献   

15.
Abstract

Densities and viscosities of four binary liquid systems decanol +n-heptane, +n-octane, +n-nonane, +n-decane, have been determined at 298.15 K and atomospheric pressure, over the complete composition ranges. The excess values of molar volume, viscosity and Gibbs free energy for the activation of flow were evaluated. The Grunberg-Nissan parameter was also calculated. The viscosity data were fitted to the equations of McAllister and Auslander.  相似文献   

16.
Abstract

Densities and viscosities of the ternary mixture (benzene + 1-propanol + ethyl acetate) and the corresponding binary mixtures (benzene + 1-propanol, benzene + ethyl acetate and 1-propanol + ethyl acetate) have been measured at the temperature 298.15 K. From these measurements excess volumes, VE , excess viscosities, ηE, and excess Gibbs energies of activation for viscous flow, G*E , have been determined. The equation of Redlich-Kister has been used for fitting the excess properties of binary mixtures. The excess properties of the ternary system were fitted to Cibulka's equation.  相似文献   

17.
Exces molar volumes, and excess viscosities of then-hexane+dichloromethane+tetrahydrofuran system have been determined at 25°C by measuring densities and viscosities. Different expressions exist in the literature to predict these excess properties from binary data. The empirical correlation of Cibulka is shown to be the best in this system.  相似文献   

18.
《Fluid Phase Equilibria》1999,166(1):53-65
This paper reports experimental densities and refractive indices of the binary systems tert-butyl alcohol (TBA)+toluene, +isooctane, and +methylcyclohexane, and toluene+methylcyclohexane, and the ternary system TBA+toluene+methylcyclohexane, over the entire range of composition at 298.15 K. Excess molar volumes and changes of refractive indices were evaluated from the experimental data obtained. These derived properties were fitted to variable-degree polynomials. The experimental values of physical properties were compared with the values estimated by different methods of prediction.  相似文献   

19.
20.
Differential thermal analysis shows many interesting properties that allow for prompt finding the place (p,T) and characteristics (endothermic, exothermic) of a phase transition or chemical reaction. In application to reactive sintering under active gas atmosphere at high pressure despite of numerous technical problems encountered during DTA measurements we found its unique possibilities. That allows for quantitative estimation of nitrogen involved in reaction of phase transition from the hexagonal phase to the cubic phase of MoN, and vice versa, in high gas pressure condition. DTA high gas pressure measurement system has the maximum operate temperature 2000°Cat pressure 2 GPa. This revised version was published online in August 2006 with corrections to the Cover Date.  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