Topologically Frustrated Polymer Dynamics and Phase Behavior of Polyzwitterions

自从地球上有生命以来，能够携带电荷的大分子就无处不在。这种大分子在制定环保材料以保护全球可持续性方面也至关重要。然而，过去一个世纪的实验表明，这些分子以难以理解和预测的神秘方式行为。这些带电的大分子在任何系统中都不是单独起作用，而是以协作的方式一起工作。对许多分子之间如此大规模的协同作用的基本理解是物理和生物科学的重大挑战之一。为了减轻这一挑战，PI将对带电大分子如何在拥挤的电解质溶液中移动，以及如何促进它们形成理想的结构，以实现新型水基材料的社会效益，形成一个基本的理解。此外，拟议的活动包括大力支持多样性和培训新一代学者，使他们将来能够参与水性材料工业和维持全球可持续性。技术概述：通过结合光散射、中子散射、荧光光谱、荧光显微镜、阻抗光谱、流变学、单分子电泳、统计力学、场论等方法，提出实验和理论发展，以研究带电大分子的层次结构和动力学、拓扑受挫非扩散动力学、凝聚凝胶复合材料以及多两性离子的组装和相图。以及几种多尺度模拟技术。具体来说，该提案解决了(a)新发现的聚合物拓扑受挫动力学状态的性质和起源，以及它向其他传统动力学模式（如劳斯-齐姆和重复）的转变，(b)控制凝聚凝胶复合材料形成的非平衡力，以及(c)偶极相互作用，以了解多两性离子的组装和相行为。本项目旨在了解带电大分子体系的复杂行为，并发现水相带电聚合物体系中结构、动力学和输运的新概念模型。对这类重要材料行为的基本理解将有助于设计新型水性聚合物材料，以确保全球可持续性，增强社会效益。在这一具有挑战性的研究领域培养研究生和博士后也是拟议活动的重要组成部分。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。

NON-TECHNICAL SUMMARYLarge molecules capable of carrying electrical charges are ubiquitous ever since life began on Earth. Such macromolecules are also vital in formulating environmentally friendly materials to guard global sustainability. However, experiments during the past century have shown that these molecules behave in mysterious ways that are difficult to understand and predict. These charged macromolecules in any system do not function alone, but all of them work together in collaborative manners. A fundamental understanding of such large scale cooperativity among many molecules is one of the grand challenges in physical and biological sciences. Towards mitigating this challenge, the PI will formulate a fundamental understanding of how electrically charged macromolecules move around in crowded electrolyte solutions, and how to facilitate them to form desirable structures toward novel water-based materials for societal benefits. In addition, the proposed activities include strong support of diversity and training a new generation of scholars and enable their future participation in industries on water-based materials and maintenance of global sustainability.TECHNICAL SUMMARYThe PI proposes experiments and theoretical developments to investigate hierarchical structure and dynamics of charged macromolecules, topologically frustrated non-diffusive dynamical state, coacervate gel composites, and assembly and phase diagrams for polyzwitterions, by combining light scattering, neutron scattering, fluorescence spectroscopy, fluorescence microscopy, impedance spectroscopy, rheology, single molecule electrophoresis, statistical mechanics, field theory, and several multi-scale simulation techniques. Specifically, the proposal addresses (a) the nature and origin of the newly discovered topologically frustrated dynamical state of polymers, and its transition into the other conventional dynamical modes, such as the Rouse-Zimm and reptation, (b) non-equilibrium forces to control formation of coacervate gel composites, and (c) dipolar interactions to understand assembly and phase behaviors of polyzwitterions. This project is aimed at understanding the intricate behaviors of charged macromolecular systems, and discovering new conceptual models for structure, dynamics, and transport in aqueous charged polymer systems. A fundamental understanding of the behavior of this important class of materials will help to design novel water-based polymeric materials to secure global sustainability with enhanced benefits to society. Training of graduate students and postdocs in this challenging research area is also an important component of the proposed activity. .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.