## Transiently Networked Fluids: Wormlike Micelles

- Oct. 13, 2015
- 4:30 p.m.
- LeConte 412

## Abstract

In highly concentrated surfactant solutions the surfactant molecules self-assemble into long flexible "wormy" structures. Properties of these wormlike micellar solutions make them ideal for use in oil recovery and in body care products (shampoo). In solution the "worms" entangle, forming a transient network, and they also continuously break and reform thus earning the name ‘living polymers’. Macroscopic rheological equations of state can describe some of the complexity of the resultant flows but, these models suffer from the need for closure approximations. Additionally these models predict exponential decay in time after a small amplitude strain whereas experiments show that, as the concentration of the solutions change, the decay is a much slower, better described by a stretched exponential or power-law. A mesoscale stochastic model is proposed and simulation results are discussed.

**Brief Bio:**

Pam Cook (-Ioannidis) is UNIDEL Professor of Mathematics at the University of Delaware; she also serves as the Associate Dean for faculty in the College of Engineering. Dr. Cook received her PhD in applied mathematics from Cornell University; followed by receipt of a N.A.T.O. Postdoctoral fellow held at the University of Utrecht, the Netherlands. She then joined the math faculty at UCLA where she received tenure. She has since been at the University of Delaware where she served as mathematics department chair for nine years. Her research has been in modeling, asymptotics, and nonlinear partial differential equations, particularly as relevant to transonic aerodynamics and complex (viscoelastic) fluids. Dr Cook is a fellow of the Society for Industrial and Applied Mathematics (SIAM), of the American Association for the Advancement of Science (AAAS), and an associate fellow of the American Institute for Aeronautics and Astronautics (AIAA). She has served as editor-in-chief of the SIAM Journal on Applied Mathematics (SIAP), as elected secretary of SIAM, as vice president for publications of SIAM, and is currently president of SIAM. She has been recognized with the national WEPAN (Women Engineers ProActive Network) University Change Agent Award, the UD Trabant Award, and the UD Torch Award, for her work in supporting, and increasing the number of, STEM women faculty at UD.