chapter
28 Pages

5. Phenomenological Coefficients of the Viscosity for Low-Molecular Elementary Liquids and Solutions

Summary ............................................................................................... 102 5.1 Introduction .................................................................................. 102 5.2 Coefficient of Viscosity for Low-Molecular Pure Liquid ............ 107 5.3 Partial Coefficients of Viscosity of the Low-Molecular Solution

Components ..................................................................................110 5.4 Characteristic Time of the Viscous Flow ......................................113 5.5 Calculation of the Diffusion Coefficients Based on the

Coefficients of Viscousity .............................................................119 5.6 Frictional and Elastic Coefficients of Viscousity of

Highmolecular Liquids ................................................................ 120 5.7 Conclusions .................................................................................. 125 Keywords .............................................................................................. 126 References ............................................................................................. 127

SUMMARY

Starting from the general phenomenological determinations of the substance flow under the action of chemical potential gradient and from the analysis of shearing forces and corresponding strains appearing into the flow it was determined that the viscosity coefficient of the pure liquid is ordered to the ratio 3 /RT Vh τ= and the expression 3 /i i iRT Vh τ= is correct for the component of the solution. The preexponential factor τ0 under expression of the characteristic time t of the viscous flow is determined not only by the frequency of the fluctuating motion of the particles in quasilattice but also by the entropic factor. Obtained expression for the activation entropy ∗∗∗ = T/HS ∆∆ explains the low values 0 2 /h kTτ << for the associated liquids and the antibate relationship between τ0 and the activation energy for the viscous flow. It was proposed the expressions permitting to calculate the coefficients of the self-diffusion and the diffusion upon corresponding coefficients of the viscosity for pure liquids and solutions. An analysis of the Maxwell’s equation and also of the deformation rates of the conformational volume of polymeric chains and their rotation permitted to mark out the frictional and elastic coefficients of the viscosity of high molecular one component liquid. It was shown, that exactly elastic coefficient of the viscosity is the gradient dependent value.