Sutherland equation

The proportionality factor F is called friction factor and is identical for diffusion and sedimentation. Using the Einstein Sutherland equation... 

Figure 3-35 Comparison of calailated diffusivity and experimental diffusivity of noble gas elements in water. Noble gas radius from Zhang and Xu (1995). Molecular diffusivity data are from Jahne et al. (1987) except for Ar (Cussler, 1997). A different symbol for Ar is used because different sources for diffusion data may not be consistent. The solid curve is calculated from the Einstein equation, and the dashed curve is calculated from the Sutherland equation. The curve from Glasstone et al. (1941) is outside the scale.

Eq. (5.248) has been obtained for the first time by Dushkin et al [138] and is a generalisation of the well-known Sutherland equation [153] for the case of micellar solutions. However, Eq. (5.248) is obtained on the basis of rather rough assumptions for the diffusion of micelles and can be used only as approximation. Note that Dushkin at al. have recently obtained a generalisation of Eq. (5.248) for slow surface dilation with a constant rate [154]. 

According to the Einstein-Sutherland equation, the diffusion coefficient D is related to the molecular frictional coefficientfo. ... 

The electrophoretic mobility p is defined as the velocity of movement induced by the effect of an electric field of 1 V/cm. On inserting into the Einstein-Sutherland Equation (7-17), one obtains, with Equation (7-26),... 

Here D is the diffusion coefficient of the solute, R is the gas constant, Tis the temperature, and y is the activity coefficient of the solute. The second expression employs the Einstein-Sutherland equation, which may be derived from the thermodynamics of irreversible processes. 

---