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1.
The viscosity and density of ternary mixtures containing $\kappa $ -carrageenan, sodium chloride, and water have been measured from (303 to 318) K at different values of pH. The presence of NaCl in the ternary systems produced an electro-viscous effect that influenced the viscosity and density of the system. The polynomial models used to correlate the viscosity and density gave good fits to the experimental data.  相似文献   

2.
Biopolymers have been the focus of intense research because of their wide applicability. The thermophysical properties of solutions containing biopolymers have fundamental importance for engineering calculations, as well as for thermal load calculations, energy expenditure, and development of new products. In this work, the thermophysical properties of binary and ternary solutions of carboxymethylcellulose and/or high methoxylation pectin and water at different temperatures have been investigated taking into consideration different biopolymer concentrations. The experimental data related to the thermophysical properties were correlated to obtain empirical models that can describe the temperature–concentration combined effect on the density, refractive index, and dynamic viscosity. From data obtained from the experiments, the density, refractive index, and dynamic viscosity increase with increasing biopolymer concentration and decrease with increasing temperature. The polynomial models showed a good fit to the experimental data and high correlation coefficients (\(R^{2}\ge \) 0.98) for each studied system.  相似文献   

3.
A recently developed scheme, based on considerations of hard-sphere theory, is used for the simultaneous prediction of the thermal conductivity and the viscosity of binary and ternary HFC refrigerant mixtures, consisting of HFC-32, HFC-125, and HFC-134a. In this prediction scheme, the hypothetical molecular parameters of HFC refrigerant mixtures were assumed to be the molar average of the pure component values. The close agreement between the predicted values and the experimental results of thermal conductivity and viscosity demonstrate the predictive power of this scheme.  相似文献   

4.
The kinematic viscosities for 273 binary and 11 ternary systems were predicted with a new model (ASOG-VISCO) developed by combining the ASOG group contribution method and Eyrings theory of absolute reaction rates. The ASOG-VISCO group pair parameters were determined from literature kinematic viscosity data for group pairs of CH2, ArCH, CyCH, OH, H2O, CO, COO, CCl3, and CCl4 in the temperature range of 283.15 to 333.15 K. The overall average deviations between experimental and predicted kinematic viscosities for the binary and ternary systems were 4.15 and 5.03%, respectively. The predicted results using ASOG-VISCO were better than those determined with the UNIFAC-VISCO group contribution method.Paper presented at the Sixteenth European Conference on Thermophysical Properties, September 1–4, 2002, London, United Kingdom.  相似文献   

5.
The viscosity of 12 binary mixtures of benzene+toluene, +ethylbenzene, +isopropylbenzene, +tert-butylbenzene; toluene+ethylbenzene, +isopro- pylbenzene, +tert-butylbenzene; ethylbenzene+isopropylbenzene; isopropylbenzene+tert-butylbenzene; o-xylene+m-xylene; m-xylene+p-xylene; and p-xylene+o-xylene has been measured over the entire range of composition. The viscosity deviations and excess Gibbs energy of activation G *E of viscous flow based on Eyring's theory have been calculated. The results have been analyzed in terms of the change in the structure of pure component molecules. The viscosity data have been correlated with the equations of Grunberg and Nissan; Hind, McLaughlin, and Ubbelohde; Tamura and Kurata; Katti and Chaudhri; McAllister; and Heric and Brewer. The Prigogine–Flory–Patterson– Bloomfield–Dewan (PFPBD) theory has been applied to analyze the excess viscosity of the present binary mixtures.  相似文献   

6.
The dynamic viscosity and the density of the ternary system, n-tridecane+1-methylnaphthalene+2,2,4,4,6,8,8-heptamethylnonane, were measured as a function of temperature from 293.15 to 353.15 K in 10 K increments at pressures up to 100 MPa. A falling body viscometer was used for measuring the dynamic viscosity above 0.1 MPa, while at 0.1 MPa the viscosity was obtained with an Ubbelohde viscometer. The overall uncertainty in the reported data is less than 1 kg·m–3 for densities and 2% for viscosities, except at 0.1 MPa where the uncertainty is less than 1%. The experimental results correspond to 882 values of viscosity. With reference to the 126 values published previously for the pure compounds and 882 values for the three associated binaries, the system is globally described by 1890 experimental values as a function of pressure, temperature, and composition. The results for the viscosity are discussed in terms of mixing laws and the excess activation energy of viscous flow.  相似文献   

7.
Viscosity and density measurements have been carried out for binary mixtures composed of methylcyclohexane + cis-decalin in the temperature range 293.15 to 353.15 K and at pressures up to 100 MPa. The viscosity was measured with a falling-body viscometer, except at atmospheric pressure where an Ubbelohde viscometer was used. The experimental uncertainty for the measured viscosities is 2%. The density was measured up to 60 MPa and extrapolated by a Tait-type relationship to 100 MPa. For the reported densities the uncertainty is less than 1 kgm–3. An evaluation of the simple mixing laws of Grunberg and Nissan and of Katti and Chaudhri, which require only the density and viscosity of the pure compounds, showed that they can represent the viscosity of the binary mixtures with an average absolute deviation of 2%, corresponding to the experimental uncertainty.  相似文献   

8.
Although a large body of viscosity data exists for simple mixtures of lighter n-alkanes, available information for heavy or asymmetric systems is scarce. Experimental measurements of viscosity and liquid densities were performed, at atmospheric pressure, in pure and mixed n-heptane, n-hexadecane, n-eicosane, n-docosane, and n-tetracosane from 293.15 K, or above the melting point, up to 343.15 K. The measured densities were correlated using the Peng–Robinson equation of state, and viscosities were modelled using the friction theory.  相似文献   

9.
The viscosity for binary mixtures of methyl acetate (MA), ethyl acetate (EA), n-amyl acetate (nAA), isoamyl acetate (iAA), decyl acetate (DeA), and dodecyl acetate (DoA) with hexane and of MA, EA, nAA, and iAA with tetrachloromethane and trichloromethane has been measured at 303.15 K over the entire range of composition. The viscosity data have been correlated with the equations of Grunberg and Nissan; Hind, McLaughlin, and Ubbelohde; Tamura and Kurata; Katti and Chaudhri; McAllister; Heric and Brewer; and Auslaender. The viscosity deviations and excess Gibbs energy of activation G*E of viscous flow based on Eyring's theory have been calculated. The results have been analyzed in terms of disruption of dipolar association of alkyl acetate and molecular interaction between alkyl acetate and chloromethane.  相似文献   

10.
This paper presents the results of density, viscosity, and electrical conductivity measurements for glycerol solutions of some alkali-metal halides at 25°C. The apparent and partial molar volumes (V and V 1) in mixtures of KCl, NaCl, KBr, KI, and glycerol were calculated from the density data. The Debye–Hückel limiting law was assumed to be valid at low concentrations, and values of the molar volumes at infinite dilution were obtained by extrapolation. The viscosity data were analyzed by means of the Jones–Dole equation. The Kaminsky method, based on reference electrolyte (on BK+ = BCl-), was used in glycerol. Viscosity B-coefficients are compared with those calculated applying existing theories based on the model of hard-charged spheres moving in a solvent continuum. Specific agreement between theory and experiment was not generally good. The electrical conductivities of solutions of salts (KCl, NaCl, KBr, NaBr, NaI, KI, and LiBr) in glycerol have been measured at three concentrations (approximately 0.01, 0.1, and 0.3 M) at 25°C. Values of the molar conductivity at infinite dilution were obtained by extrapolation using the conductance equation of Onsager. Using previously measured transference numbers for KCl and NaCl in glycerol, values of limiting Walden products for the individual alkali-metal and halide ions in glycerol have been derived and compared with those in aqueous and other alcohol solutions.  相似文献   

11.
12.
Thermodiffusion separation of the binary mixtures of argon with an ethanol, n-propanol, and iso-propanol vapor and the binary mixtures of ethanol with an n-propanol and iso-propanol vapor has been measured in the temperature range 331–347 K by the two-flask method and the thermodiffusion factor has been determined. The experimental values of the thermodiffusion factor have been compared to the results of calculation according to the Chapman-Enskog theory. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 3, pp. 82–85, May–June, 2005.  相似文献   

13.
This paper reports density and viscosity measurements for the binary mixtures of cyclopentane or cyclohexane or benzene with 1,3-dioxolane at 283.15, 298.15, and 313.15 K. From the experimental data, excess volumes and excess viscosities were calculated and the results were fitted to a Redlich–Kister-type equation. The results are discussed in terms of molecular interactions. The Prigogine–Flory–Patterson and Blomfield–Dewan theories were used to analyze the results at 298.15 K.  相似文献   

14.
The dynamic viscosity and the density of the associative ternary mixture water+diacetone alcohol+2-propanol have been measured as a function of temperature T (303.15, 323.15, and 343.15 K) and pressure P (100 MPa). The experimental results correspond to 698 values of and . With reference to the 54 values previously published on pure substances and 486 values for three corresponding binaries, the system is globally described by 1188 experimental values for various values of P, T and composition. The results for are discussed in terms of excess activation energy of viscous flow.  相似文献   

15.
Several thermophysical properties of R507, a binary refrigerant mixture, and R404A, a ternary mixture, have been determined by dynamic light scattering (DLS), in both the liquid and the vapor states, along the saturation line approaching the vapor–liquid critical point. Data for the thermal diffusivitya and sound speed c S cover a range of temperatures down to 270K, and data for the surface tension and kinematic viscosity down to 230K. For both mixtures the behavior of all properties determined can be correlated well by the mass-weighted sum of the respective pure component data, when all data are represented as a function of the reduced temperature.  相似文献   

16.
17.
This study presents the viscosities, both kinematic and dynamic, of binary mixtures of 1-chlorobutane, 2-chlorobutane, or 1-chloro-2-methylpropane with butyl ethyl ether or methyl tert-butyl ether from $T = 283.15$  K to $T = 313.15$  K at atmospheric pressure as a function of composition. Kinematics viscosities were measured using an Ubbelohde viscometer. The dynamic viscosities were obtained from experimental kinematic viscosities and previously reported density data. The viscosity results have been employed to check the reliability of the Wu-UNIFAC method.  相似文献   

18.
从高技术应用的要求出发,论述了纯质及氮-烃类混合工质的不足,用PR方程分析了成分配比对二元氮-氟里昂混合工质节流循环特性的影响,指出合理的成分配比对二元氮-氟里昂混合工质是十分必要的。并以不同温度下的△H_T为目标函数,优化计算了一些二元氮,氟里昂低温混合工质的最佳成分配比。  相似文献   

19.
In this work, viscosities of binary mixtures of isomeric chlorobutanes with diisopropylether have been determined as a function of composition under atmospheric pressure and in the temperature range from 283.15 K to 313.15 K with steps of 5 K. Kinematics viscosities were measured using an Ubbelohde viscosimeter; absolute viscosities were obtained from kinematic viscosities and densities. Finally, we have used the Asfour method for predicting the dependence of viscosity with composition and comparing it with our experimental data.  相似文献   

20.
Densities of ethyl acetate + dibromomethane, + bromochloromethane, + 1,2-dichloroethane, or + 1-bromo-2-chloroethane binary mixtures were measured at 288.15, 298.15, and 308.15 K over the entire composition range. Thermal expansion coefficients and excess molar volumes were calculated. Moreover, densities at 298.15 K at pressures up to 200 bar were determined for the same mixtures. Isothermal compressibilities of the pure liquids and their mixtures were obtained. The excess molar volumes are positive, and the excess isothermal compressibilities are negative for all the studied mixtures.  相似文献   

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