Microscopic Details of Polymer Dynamics: From Fast Dynamics to Segmental and Chain Relaxations

技术摘要：聚合物材料的大多数独特性质都是由其分子运动的特性来定义的。因此，了解聚合物动力学的基本原理对于设计具有所需宏观性能的新型先进材料至关重要。所提出的工作集中在聚合物动力学的各个方面，从皮秒时间尺度上的微观行为(快速动力学)到主要的结构松弛(链段动力学)和链动力学。这项研究的主要目的是揭示潜在现象的微观机制，并探索化学结构和分子间相互作用在不同时间和长度尺度上对分子运动的作用。这项拟议的工作旨在创建一种统一的方法，能够描述不同时间和长度尺度上的聚合物动力学，并根据聚合物的化学结构预测聚合物的宏观性质。该计划采用了大量的实验技术(光、中子和X射线散射、介电和机械弛豫光谱)，提供了有关聚合物动力学所有组成部分的详细微观信息。该计划包括与美国(包括行业)和欧洲的几个组织进行广泛的合作。这些结果将对聚合物科学产生重大影响，并将对复杂系统的动力学、材料科学和一般物理产生重大影响，并通过更好地了解生物大分子的动力学对生物物理学产生重大影响。非技术摘要：基于聚合物的材料在我们的日常生活中的重要性正在急剧增加，未来聚合物在包括光子学、电子学和生物技术在内的技术中的应用前景将更加广阔。分子运动是决定聚合物许多宏观性质的关键。拟议中的研究侧重于对不同时间和长度尺度上的分子运动的基本理解，并将影响材料科学、物理和生物物理的各个领域。此外，了解分子结构和动力学之间的关系将对设计和合成用于先进技术的新型聚合物材料具有重要影响。拟议的计划涉及广泛的国际合作，与NIST和ANL的国家多用户设施以及与当地行业的合作。拟议的计划还通过研究生和本科生积极参与这项研究、研究生课程的开发，对未来专家的教育产生重大影响。还注意与代表性不足的群体和K-12学生的外联工作。

TECHNICAL SUMMARY:Most of the unique properties of polymeric materials are defined by peculiarities of their molecular motions. Thus, understanding fundamentals of polymer dynamics is crucial for design of novel advanced materials with desired macroscopic properties. The proposed work is focused on various aspects of polymer dynamics, from microscopic behavior on picosecond time scales (fast dynamics) to the main structural relaxation (segmental dynamics) and chain dynamics. The main goal of this research is to unravel the microscopic mechanisms of the underlying phenomena and to explore role of chemical structure and inter-molecular interactions on molecular motions at different time and length scales. The proposed work aims at creation of a unified approach that will be able to describe polymer dynamics at different time and length scales and predict macroscopic properties of polymers based on their chemical structure. A broad number of experimental techniques (light, neutron and X-ray scattering, dielectric and mechanical relaxation spectroscopy) employed in this program provide detailed microscopic information on all components of polymer dynamics. The program includes broad collaborations with a few groups in the US (including industry) and in Europe. The results will have significant impact on polymer science, and in broader aspect on dynamics of complex systems, materials science and physics in general, and also on biophysics through a better understanding of dynamics of biological macromolecules.NON-TECHNICAL SUMMARY:The importance of polymer-based materials in our everyday life is growing dramatically and even broader perspectives are expected for the use of polymers in future technologies, including photonics, electronics and bio-technologies. Molecular motions present the key to many macroscopic properties of polymers. The proposed research focuses on fundamental understanding of molecular motions at different time and length scales and will impact various fields of materials science, physics and biophysics. Moreover, understanding the relationship between molecular structure and dynamics will have significant impact on design and synthesis of novel polymeric materials for advanced technologies. The proposed program involves broad international collaboration, collaboration with national multi-user facilities at NIST and ANL and with local industry. The proposed program also significantly impacts education of future specialists through active involvement of graduate and undergraduate students in this research, developments of graduate courses. Attention is also paid to work with underrepresented groups and K-12 students outreach.