Fellow 1990-91

Steve Granick

Materials Science & Engineering

Surface Motions and Relaxations at the Solid-Liquid Interface

Two experiments are proposed in the context of a broader research program which seeks to understand on a molecular basis, the organization and dynamics of polymer liquids at well-characterized single solid surfaces. The emphasis on dynamics contrasts with the traditional emphasis on structure. The following experiments are proposed: (A) To test a hypothesis regarding the molecular origin of reversibility or irreversibility of polymer adsorption, by direct measurements of exchangeability and of the time-dependent fraction of segments directly at the solid surface, and (B) To probe, for the first time, the shear dynamics of adsorbed high polymers in solution but in near-molecular proximity. If successful, results will give significant information regarding how and why the dynamics of polymer fluids near a solid boundary differ from those in the unconstrained bulk.