schubeba@che.udel.edu

Phase behavior, rheology, and microstructure of surfactant solutions

The goals of this project are to explore the effect of shear and extensional flows on the microstructure and phase behavior of surfactant solutions. Structure-property relations will be initially determined experimentally for model nonionic surfactant solutions, and these will highlight links between rheology, microstructure, and phase behavior. Rheological measurements will be combined with those of small angle neutron and light scattering under flow, as well as measurements of flow birefringence and dichroism.

The work will be extended to examine the influence of ionic surfactants and added electrolytes on both microstructure and rheology. After significant experimental progress has been achieved, modeling will be done at two levels. The first goal will be to characterize the structure property relationships in terms of "mesoscopic" parameters, such as bilayer bending constants. The second goal will be to relate these mesoscopic parameters to the molecular structure of the chemical components. Such modeling will help to organize and understand the results of experiments on model systems, with the goal of providing tools for the rational design of microstructured surfactant solutions.