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

聚合物薄膜在广泛的纳米技术中是不可或缺的。对于某些应用，它们的厚度需要小于聚合物分子的大小。然而，具有这种厚度的薄膜相对于它们的块状类似物具有本质上不同的材料特性。了解聚合物薄膜的基本结构-性能关系是实现其合理设计的关键。在这个项目中，PI和一名来自南密西西比大学的女研究生将与莱斯大学的专家合作。该团队将通过先进的光学成像方法直接阐明纳米级约束如何改变聚合物链的微观结构、迁移率和系统非均质性。该项目将加强PI小组的单分子成像能力，并在机构之间开展新的合作。这些资源将用于改善密西西比州的研究基础设施，以及开发新的课程和研讨会材料，以教育未来的STEM研究人员和加强社区外展。这个RII Track-4奖学金项目的总体目标是通过实时空间成像，获得关于薄膜约束对聚合物链动力学和构象的完整的分子水平的理解。具体来说，单粒子跟踪（SPT）和单分子Förster共振能量转移（sm-FRET）方法将用于表征聚合物迁移率及其端到端距离作为膜厚度和基质分子量的函数。这两种成像技术都非常适合同时检测数百个单个分子。在本项目中，SPT和sm-FRET的结合使用将阐明聚合物薄膜的多相链行为，这对其有效的系统设计尤为重要。此外，该奖学金项目将建立一个平台，以提高PI所在机构和密西西比州的光学成像能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.