RII Track-4: NSF: Elucidating heterogeneous single chain conformation and dynamics in thin films through optical imaging

University Of Southern Mississippi, Hattiesburg MS

Investigators

Abstract

Polymer thin films are indispensable in a wide range of nanotechnologies. For some applications, their thickness needs to be less than the size of a polymer molecule. However, films with such thickness can have substantially different material properties relative to their bulk analogs. Understanding the fundamental structure-property relationship of polymer thin films is crucial for enabling their rational design. In this project, the PI and a female graduate student from the University of Southern Mississippi will work with experts at Rice University. The team will directly elucidate how nanoscale confinement alters polymer chain microstructures, mobility, and system heterogeneity through advanced optical imaging methods. This project will strengthen single-molecule imaging capabilities in the PI’s group and develop new collaborations between institutions. These resources will be leveraged to improve the research infrastructures in Mississippi, as well as to develop new course and workshop materials for educating future STEM researchers and enhancing community outreach. The overarching goal of this RII Track-4 fellowship project is to obtain a complete, molecular-level understanding about thin film confinement effects on polymer chain dynamics and conformations through real-space, real-time imaging. Specifically, single-particle tracking (SPT) and single-molecule Förster resonance energy transfer (sm-FRET) methods will be employed for characterizing polymer mobility and their end-to-end distances as functions of film thickness and matrix molecular weight. Both imaging techniques are uniquely suited for simultaneously examining hundreds of individual molecules. The combined use of SPT and sm-FRET in this project will elucidate heterogenous chain behaviors of polymer thin films, which are particularly important for informing their efficient system design. Furthermore, this fellowship program will establish a platform to advance optical imaging capabilities in the PI’s home institution and the state of Mississippi. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.