On the contribution of direct intermacromolecular interactions to the viscosity of a suspension of hard spheres

The contribution of the contact interaction to the shear and bulk viscosities 1) and 1), of a suspension of hard spheres is evaluated by use of the Green-Kubo integral forms. To lowest (second) order in the volume fraction . 1) = 1)0(\ + 13.442) and 1), = 1),0(\ + 4.321)02). Since [J. Chern. Phys. 67. 4690 (\ 977)] direct interactions contribute to the drag coefficient f in first order in the density. a sphere suspension whose dissipative properties include a substantial contribution from direct intermacromolecular interactions is predicted not to show Debye-type behavior. i.e.. for such a system f /1) will not be independent of concentration.