Systems involving deformable interfaces between immiscible fluids offer a significant challenge for materials design and processing. Static interfacial/surface tension is often the only parameter considered in the design of systems with fluid-fluid interfaces. In foams, emulsions, blends, sprays, droplet-based microfluidic devices and many other applications, the dynamic nature of surface active species and deformation of interfaces requires a more detailed characterization of the interfacial transport, dynamic interfacial properties and interfacial structure. Macroscopic properties and the ability to tune and control phenomena requires an improved understanding of the time-dependent properties of the interfacial tension and interfacial mechanics. We have developed tools and approaches to quantify the impact of surface active species on interfacial behavior. Simple surfactants at interfaces make evident the need to characterize timescales in the adsorption problem. Polymer-grafted nanoparticles, polymer-surfactant aggregates and proteins show the ability to bridge between macromolecular and particulate (Pickering) laden interfaces. This talk will provide the motivation to use microscale interfaces for efficient analysis of complex interfacial phenomena and how that relates to the material properties of interface-dominated materials.<\p>
Seminars are open to alumni, friends of the Department, and the general public.