Polymer Surface Dynamics

Abstract

A major surge of activity is underway to understand the dynamics of polymer chains at interfaces. This stands in contrast to the situation a generation ago when much of polymer-materials research revolved around understanding dynamics in the bulk (isotropic) state. Building in part on earlier studies that had been somewhat neglected, striking new findings have been obtained. The new methods and equipment include surface-specific spectroscopies; advanced, in situ time-resolved methods to determine surface structure and composition; and the surface-forces apparatus for measuring adhesion and interfacial rheology. Also, older methods (such as contact angle) have been revitalizated and applied to new problems. Theoretical calculations and molecular-dynamics simulations are also emerging.Appreciation is growing that scientific understanding is possible of these systems that are so complex and, often, so far from equilibrium. Polymer surfaces are becoming recognized as an area with many opportunities to do exciting and useful surface science, particularly regarding kinetics, diffusion, surface chemistry, and other rate-dependent processes.The engineering significance is that while polymers and plastics-based applications are rooted in our economic life, too often the technologies and formulations are empirically derived. One tends to take plastics and their communication with adjoining materials for granted. A molecular understanding is needed so that better design can emerge by rational extension.During the course of these new activities, the community of polymer science has rubbed shoulders with and has thereby become increasingly integrated with other disciplines-colloid science, surface science, biomedical science, and microelectronics, to cite a few examples. When dealing with interfaces, one's parochial materials interests quickly become generalized.