Viscosity binary solutions

The viscosities of many binary liquid systems display minima as functions of composition at constant temperature, so that negative values of D are also possible. Yajnik and his coworkers (265 ) long ago observed that very frequently an extremum in the isothermal vapor pressure-composition curve is accompanied by an extremum of the opposite sense in the viscosity-concentration curve. Data are apparently not available for solutions of very low-molecular-weight paraffins in carbon tetrachloride, but minima are found for the viscosities of solutions of CC14 with ethyl iodide, ethyl acetate and acetone, so that a minimum appears quite probable for mixtures of small aliphatic hydrocarbons with carbon tetrachloride. If this were true, the downward trend of the Meyer-Van der Wyk data on C17—C31 paraffins, earlier discussed in connection with the polyethylene plots of Fig. 14, would be understood. It will be recognized that such a trend is also precisely what is to be expected from the draining effect of the hydrodynamic theories of Debye and Bueche (79), Brinkman (45 ) and Kirkwood and Riseman (139). However, the absence of such a trend in the case of polyethylene... 

VISCOSITIES OF BINARY SOLUTIONS OF NITROPARAFFINS IN CARBON TETRACHLORIDE. 

The electrolytic conductivity of 1 moldm" LiPF6/DFNMOmix was much lower than that of NMO due to the high viscosity and low permittivity. The oxidation potential of DFNMOmix on Pt was increased but still lower than that of PC. The addition of DFNMOmix to 1 moldm LiPF6/EC-DEC equimolar binary solution suppressed discharge capacity fading in a Li/LiCo02 cell. 

HDPE is not soluble in any known solvent at room temperature, although several solvents (ie, xylenes) have a swelling effect. However, certain binary solution mixtures including CS2 dissolve HDPE at as low as 30-40°C. Above 80°C HDPE dissolves in many aliphatic and aromatic hydrocarbons and their halogen-substituted derivatives. Solvents most frequently used include xylenes, tetralin, decalin, o-dichlorobenzene, 1,2,4-trichlorobenzene, and 1,2,4-trimethylbenzene. These solvents are employed for the determination of molecular weights from solution-viscosity data or by gpc. 

Easteal AJ, Angell CA (1972) Viscosity of molten zinc chloride and supercritical behavior in its binary solutions. J Qiem Phys 56 4231 234... 

Moreover, from the no negligible deviations between the viscosities values for ternary aqueous solutions of caffeine and CaC, and those obtained for binary systems at the same temperatures and with the same technique (<1%), we may also conclude that caffeine affects the behavior of the viscosity of solutions of CaC. ... 

As it has appeared in recent years that many hmdamental aspects of elementary chemical reactions in solution can be understood on the basis of the dependence of reaction rate coefficients on solvent density [2, 3, 4 and 5], increasing attention is paid to reaction kinetics in the gas-to-liquid transition range and supercritical fluids under varying pressure. In this way, the essential differences between the regime of binary collisions in the low-pressure gas phase and tliat of a dense enviromnent with typical many-body interactions become apparent. An extremely useful approach in this respect is the investigation of rate coefficients, reaction yields and concentration-time profiles of some typical model reactions over as wide a pressure range as possible, which pemiits the continuous and well controlled variation of the physical properties of the solvent. Among these the most important are density, polarity and viscosity in a contimiiim description or collision frequency. 

Diffiusion Coefficient. The method of Reference 237 has been recommended for many low pressure binary gases (238). Other methods use solvent and solute parachors to calculate diffusion coefficients of dissolved organic gases in Hquid solvents (239,240). Molar volume and viscosity are also required and may be estimated by the methods previously discussed. Caution should be exercised because errors are multiphcative by these methods. 

For predicting liquid diffiisivities of binary nonpolar liquid systems at high solute dilution, Umesi " developed a method that only depends on the viscosity of the solvent (2) and the radius of gyration of the solvent (2) and the solute (1). The Technical Data Book— Petroleum Refining gives the method and values of the radii of gyration for common hydrocarbons. Errors average 16 percent but reach 30 percent at times. 

The diffusivity of solute 1 in the mixture is related to the binary infinite dilution diffiisivities for each of the other components calculated from Eq. (2-155) or the Umesi method. The viscosities are calculated by the methods in the previous section. Errors are not quantifiable, as little experimental data exist, although these errors would be related to those assumed for the binaiy pairs. 

The solute 1 is dissolved in a solvent pair of 2 and 3. D are infinite dilution binary diffusivities estimated by the proper method discussed previously. The mixture viscosity can be predic ted by methods of the previous section. The average absolute error when tested on 40 systems is 25 percent. The method gives higher errors if the solute is gaseous. 

Tables and correlating equations for density, vapor pressure, thermal conductivity and viscosity of binary and ternary solutions...

Transition Region Considerations. The conductance of a binary system can be approached from the values of conductivity of the pure electrolyte one follows the variation of conductance as one adds water or other second component to the pure electrolyte. The same approach is useful for other electrochemical properties as well the e.m. f. and the anodic behaviour of light, active metals, for instance. The structure of water in this "transition region" (TR), and therefore its reactions, can be expected to be quite different from its structure and reactions, in dilute aqueous solutions. (The same is true in relation to other non-conducting solvents.) The molecular structure of any liquid can be assumed to be close to that of the crystals from which it is derived. The narrower is the temperature gap between the liquid and the solidus curve, the closer are the structures of liquid and solid. In the composition regions between the pure water and a eutectic point the structure of the liquid is basically like that of water between eutectic and the pure salt or its hydrates the structure is basically that of these compounds. At the eutectic point, the conductance-isotherm runs through a maximum and the viscosity-isotherm breaks. Examples are shown in (125). 

In a previous publication ( ), results were presented on the micellar properties of binary mixtures of surfactant solutions consisting of alkyldimethylamine oxide (C12 to Cig alkyl chains) and sodium dodecyl sulfate. It was reported that upon mixing, striking alteration in physical properties was observed, most notably in the viscosity, surface tension, and bulk pH values. These changes were attributed to 1) formation of elongated structures, 2) protonation of amine oxide molecules, and 3) adsorption of hydronium ions on the mixed micelle surface. In addition, possible solubilisation of a less soluble 1 1 complex, form between the protonated amine oxide and the long chain sulfate was also considered. 

Zafarani-Moattar, M.T. and Shekaari, H. Volumetric and speed of sound of ionic liquid, l-butyl-3-methylimidazolium hexafluorophosphate with acetonitrile and methanol at T = (298.15 to 318.15) K, /. Chem., Eng. Data, 50,1694,2005. Wang, J. et al.. Excess molar volumes and excess logarithm viscosities for binary mixtures of the ionic liquid l-butyl-3-methylimidazolium hexafluorophosphate with some organic solvents, /. Solution Chem., 34, 585, 2005. 

In order to explain the experimental behavior found of X for PVP in the different mixtures, the polarizability was taken into account because of the methyl groups substituents of the aromatic ring. It is possible to And changes in the nature of the interactions between the polar solute, 2 - propanol, and the aromatic component in the binary mixtures and that these changes affect the X values. The importance of dipole - induced dipole interactions and steric factors in the formation of a molecular complex between a polar component and a non - polar aromatic solvent has been emphasized on the basis of NMR studies [111, 112], The molecular interactions in binary liquid mixtures have also been studied on the basis of viscosity measurements. The viscosity data have also been used by Yadava et al. [113,114] to obtain a value for the interchange energy (Wvisc) [115] This parameter can be estimated by the equation ... 

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