(408e) Low Concentration Dynamic Surface Tension Measurements of Macromolecular Systems

Alvarez, N. - Presenter, Carnegie Mellon University
Walker, L. M. - Presenter, Carnegie Mellon University
Anna, S. L. - Presenter, Carnegie Mellon University

There are several advantages of measuring dynamic surface tension at high interfacial curvature (small radii). Two advantages are that measurements require less volume and the equilibration time is orders of magnitude faster than pendant bubble/drop measurements. Using a newly developed apparatus, we now have the ability to study low concentrations of macromolecular systems to better understand the governing transport mechanisms on and off gas-liquid and liquid-liquid interfaces. This study examines the equilibration time of macromolecular species as a function of interfacial curvature and quantitatively compares the relaxation time for compression-expansion experiments at different surface coverage. Examples include surfactant-polyelectrolyte aggregates and macromolecules undergoing surface induced conformational changes.