EFFECT OF A SOLID LIQUID INTERFACE ON BULK SOLUTION STRUCTURES UNDER FLOW/

It has been known for some time that a shear field can impart enough e nergy to a liquid system for it to exhibit a phase change. Not as well appreciated is the fact that non-Newtonian solutions can be driven in to a quasi-phase separation due to the vastly different shear rates be tween the bulk and near-surface regions. Using a variety of scattering techniques we have probed the interfacial and near-surface region of a system of wormlike colloidal particles under how separately from the bulk. We find that the hexagonal phase which forms under flow near th e surface, does not persist into the bulk. We also present data showin g substantial differences in the kinetics of alignment and relaxation of the two phases. (C) 1998 Elsevier Science B.V. All rights reserved.