Viscosity liquid phase

Comparison of weighting methods for liquid phase viscosities. Mixture of n-hexane - n-hexadecane at 298 K. 

With regard to the liqiiid-phase mass-transfer coefficient, Whitney and Vivian found that the effect of temperature upon coiild be explained entirely by variations in the liquid-phase viscosity and diffusion coefficient with temperature. Similarly, the oxygen-desorption data of Sherwood and Holloway [Trans. Am. Jnst. Chem. Eng., 36, 39 (1940)] show that the influence of temperature upon Hl can be explained by the effects of temperature upon the liquid-phase viscosity and diffusion coefficients. 

Phase densities differ by a Phase densities differ by only about 10%. factor of 100-10,000 1. Viscosity in both phases is Liquid phase viscosity moderate, solid low. phase rigid. Phase separation is rapid Phase separation is slow surface-tension and complete. effects prevent completion. Countercurrent contacting is Countercurrent contacting is slow and quick and efficient. imperfect. ... 

Ref. [44]), but this equation is valid only for dilute solutions. At higher electrolyte concentrations, another, empirical equation by Gordon (see Ref. [44]) should be applied, which takes the influence of the liquid phase viscosity into account... 

The correlations of Onda et al. [60] and Billet [10] are valid for various mixtures and packing types. The correlation of Kolev [61] represents a further development of the model by Onda et al. [60], with an extended validity area for the liquid-phase viscosity. 

The rate of foam drainage is determined not only by the hydrodynamic characteristics of the foam (border shape and size, liquid phase viscosity, pressure gradient, mobility of the Iiquid/air interface, etc.) but also by the rate of internal foam (foam films and borders) collapse and the breakdown of the foam column. The decrease in the average foam dispersity (respectively the volume) leads the liberation of excess liquid which delays the establishment of hydrostatic equilibrium. However, liquid drainage causes an increase in the capillary and disjoining pressure, both of which accelerate further bubble coalescence and foam column breakdown. 

The characteristic length scale, a, is the hydraulic radius of the channel at some reference point, the velocity, U, is the gas velocity at that point, and a is the surface tension. The starred quantities are dimensional. The capillary number, Ca, is based on the reference gas velocity and the liquid phase viscosity. The flow coefficient is defined as... 

One important characteristic of microemulsion viscosity is that it is a strong function of phase compositions. In UTCHEM, liquid phase viscosities are modeled as a function of pure component viscosities and the phase concentrations of the organic, water, and surfactant ... 

One effect of diffusivity on the reaction rate constant of a bimolecular reaction has been proposed by Atkins (Equation 20.1) (Atkins, 1982). The Stokes-Einstein equation (Equation 20.2) (Edward, 1970) relates molecular size and local liquid phase viscosity to diffusion on very small scales. Eor the purposes of this review, we will refer to this type of diffusion as local translational diffusion. 

Application of subcritical gaseous CO2 to an organic liquid causes the liquid phase to expand noticeably, due to extensive dissolution of the CO2 into the liquid phase (131). This expansion is accompanied by a reduction in the liquid phase viscosity, an increase in the solubility of H2 in the liquid, and an increase in the mass transfer rates from the gas to liquid phase. There is evidence that this can affect the enantioselectivity of reactions in viscous liquids. The enantioselectivity of asymmetric hydrogenation of unsaturated carboxylic acids in a viscous ionic liquid was shown to be strongly affected by CO2 expansion of the liquid, the enantioselectively being improved for one substrate (atropic acid) and decreased for another (tiglic acid). The results were explained in terms of the solubility and rate of transfer of H2 gas into the expanded ionic liquid (23). The same effect was not observed in expanded methanol. 

Under model conditions ethyleneglycol as a hydrolysis product increases solubility of Ca (OH)2. However, its accumulation or introduction into the beaded mill as a component of the liquid phase does not lead to hydrolysis intensification. Probably it occurs because presence of ethyleneglycol promotes the growth of liquid phase viscosity that may be connected with increase in solubility of calcium salt of terephthalic acid in liquid phase of the reaction mixture. In consequence of this significant drop in efficiency of the beaded mill work is observed. 

Role of Liquid-Phase Viscosity. As in any fluid flow process, the liquid viscosity offers resistance to flow and has a direct bearing on the rate of drainage of the liquid from foam films. The rate of film thinning will decrease as the liquid viscosity increases, and in the extreme case of very high viscosity (for example, the solidified films of latex foam), the resistance to flow can make the foam very stable. 

Because of the limited magnitude of surface tension gradients and absence of electric double-layer effects, the stabilization of foams in nonpolar liquids requires other ways of retarding the thinning of foam lamellae. These include the high liquid-phase viscosity that has been discussed earlier and increased surface viscosity because of presence of highly viscous or even rigid liquid-crystal films. 

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