Complex Fluids & Colloids

Several faculty groups study the flow and colloidal behavior of fluid suspensions including particulates, droplets, capsules and vesicles. The Leal group has pioneered studies on the stability, coalescence and break-up of emulsion droplets and bubbles in a wide variety of well-controlled flows. Leal and Israelachvili are investigating the formation and stability of vesicles and vesicle suspensions, and how these self-assembled structures are deposited on surfaces. The Helgeson group is developing methods for the preparation of nanodroplets with complex internal structure that enable sophisticated nanoencapsulation strategies for pharmaceuticals and diagnostic agents.

The Helgeson group uses novel material systems and experimental methods to understand the formation and rheology of colloidal gels, which are ubiquitous for formulating consumer products, foods, pharmaceuticals and coatings. In particular, they are examining the development of large-scale structure during the gelation process (both at rest and under flow), and how it controls the performance of these materials.

Professor Segalman investigates ionically and electrically conductive complex coacervates, for which both ionic and polymer backbone interactions drive structure formation. Modeling of structure and physical properties of this system is in collaboration with Fredrickson.

The Mitragotri group seeks to understand and control how the colloidal properties of drugs, particles, and cells affect their transport within biological systems. A recent example includes the design of synthetic, biomimetic ‘red blood cells’ with specific transport properties that enhance their circulation, biodistribution and controlled aggregation.