Polymer Dynamics at Interfaces and in Complex Environments

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

TECHNICAL SUMMARY This research focuses on a central problem of polymer physics ? how polymers diffuse along the solid-liquid interface and in confined geometries. This will be studied using novel experimental platforms of fluorescence spectroscopy, sometimes with single-molecule resolution (FCS, fluorescence correlation spectroscopy), sometimes with FRAP (fluorescence recovery after photobleaching), sometimes with FRET (Förster resonance energy transfer), sometimes with single-particle imaging. As implemented, these experiments will yield spatially-resolved measurements with spatial resolution <0.5 &#956;m. The research will focus on the polymer side of the interface ? the dependence of polymer translational diffusion on chain length, polymer surface coverage, and in the case of confined polymer melts, on film thickness -- seeking to understand the universal aspects of this problem. The intellectual merit is to develop new understanding of how polymers diffuse at surfaces and in confined geometries, which is fundamental in many scientific and technical applications, including adhesion, interdiffusion, friction, the mechanical behavior of composite and nanocomposite materials, and functional properties of other kinds, and also to develop new experimental tools to quantify polymer mobility in ultra-thin films that are impossible to characterize by conventional methods. The graduate students will be part of an interdisciplinary research group with other students from chemistry, chemical engineering, physics, and materials science, integrating research and education. NON-TECHNICAL SUMMARY This research seeks new fundamental understanding of how polymers and plastics move about at surfaces and in confined geometries. One of the most pressing unsolved problems of polymer science, to solve it will open the door to technical applications and technological improvement in areas including adhesion, friction, composite and nanocomposite materials, and functional materials. This research will produce new experimental tools to quantify polymer mobility impossible to characterize by conventional methods. This will improve research infrastructure in the polymer field. This laboratory has an excellent track record regarding diversity, especially in involving women undergraduate and graduate researchers, and integrating research with education. The broader impact of this research involves strong connections with industry, with international collaborators, and the promotion of educational diversity.