TRANSPORT-PROPERTIES OF A SPHERICAL MOLECULE IN SOLVENT WITH POSITION-DEPENDENT VISCOSITY

The rotational friction coefficient of a spherical molecule in solution is calculated applying the Navier-Stokes equation for a continuum solvent with a position-dependent viscosity as a model of ''microscopic viscosity.'' The rotational friction coefficient decreases with decreasing surface viscosity The results are compared with the translational friction and viscosity B coefficients which are previously obtained from the same model. The B coefficient is most sensitive to a local viscosity change. The Gierer-Wirtz model overestimates the effect of the ''microscopic viscosity'' on the translational friction coefficient comparing with the present results.