Neutron Scattering Studies Of Near Surface Structures In Surfactant Systems*, W.A. Hamilton, P.D. Butler and J.B. Hayter, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6393, USA; and L.J. Magid and Z. Han, Department of Chemistry, University of Tennessee-Knoxville, TN 37996-1600, USA.

A solid surface can be expected to modify nearby surfactant structures in solution both statically, due to the geometric constraints imposed by its presence and interactions with any adsorbed layer, as well as dynamically by Poiseuille shear in flow past it. A combination of neutron reflectometry, near-surface small angle neutron scattering (NSSANS) from reflection geometry cells, and bulk SANS from both static and Couette sheared samples, enables us to track the evolution of surface structures into bulk structures as a function of distance from the solid-liquid interface. We present results of this approach applied to the near surface ordering of systems of charged spheroidal and highly extended threadlike micelles, as well as to the near-surface alignments of multilamellar surfactant systems.

*Research supported by the Division of Materials Sciences, US-DOE (ORNL is managed under contract DE-AC05-96OR22464 with Lockheed-Martin Energy Research Corporation).