Abstract Proposal Number: CTS 9803478, CTS 9803683 Principal Investigator: Hirsa/Lopez This is a grant to study the intrinsic properties of surfactant-influenced gas/liquid interfaces. The program will capitalize on newly developed non-invasive optical techniques for surface chemistry and interfacial hydrodynamics. These properties will be measured directly and incorporated into the governing equations that are derived from first principles without the need for phenomenological modeling. A focused, interdisciplinary research effort incorporating the theoretical formulation of the problem, surface chemistry and hydrodynamic experimentation and measurement, and numerical simulation set the stage for a possible major breakthrough in the field of interfacial flow dynamics. Applications of surfactant hydrodynamics are diverse and include material (e.g. plastics) and food processing, fuel injection spray and atomization, two-phase flow, C02 transport across the ocean surface, and pulmonary surfactant therapy. Also, the development of new surfactants can benefit from the results of the proposed project from improvements in the methodology to measure the intrinsic interfacial properties. These measurement capabilities coupled with the predictive model can shift the design of surfactant materials from a trial-and-error process to a systematic design paradigm based on the principles of mechanics. The aim of this project is to elucidate the role of intrinsic interfacial properties, including surface viscosities (dilatational and shear) and transport kinetics, on the bulk and interfacial transport processes through a mechanistic formulation. This will be accomplished with a simple, reproducible, steady-state flow field, using an experiment in an annular channel flow (the deep-channel viscometer). 1 1
