Topologically Frustrated Dynamics and Memory in Polyelectrolyte Systems

聚电解质系统中的拓扑受挫动力学和记忆

• 批准号: 2004493
• 负责人: Murugappan Muthukumar
• 金额: $ 49万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2004493&HistoricalAwards=false
• 关键词: Topologically; Frustrated; Dynamics; Memory; Polyelectrolyte

NON-TECHNICAL SUMMARYMacromolecules made of monomers carrying electrical charges are ubiquitous in all living organisms and continue to catalyze formulations of modern water-based materials. A fundamental understanding of the behavior of such charged macromolecules dispersed in aqueous electrolyte solutions continues to be a challenge. The origin of the challenge lies on the fact that these molecules do not behave on their own as individual molecules, but they are correlated over very large distances spanning the whole collective system. As a result, the properties of charged macromolecules are full of challenges without adequate conceptual framework to understand their rich phenomenology. In fact, formulation of a fundamental understanding of such strongly correlated macromolecules remains one of the most difficult subjects in physical and biological sciences. Yet, such a fundamental understanding is crucial to successfully design new materials for separation science, highly water-absorbent goods, drug delivery, water-based electrical conductors, and memory devices, in addition to rationalizing the rich phenomenology already accumulated over many decades. The PI proposes to formulate a fundamental understanding of how electrically charged macromolecules move around in an electrolyte solution, or inside a gel, or from one region to another through intervening barriers due to crowding, and how to endow macromolecular memory effects in water-based systems. In addition to advancing the field of charged macromolecules, the proposed activities include strong support of diversity and training a new generation of scholars to enable their future participation in the multi-billion dollar industry of water-based materials.TECHNICAL SUMMARYThe PI proposes experiments and theoretical developments to investigate polyelectrolyte dynamics, polyelectrolyte gel dynamics, topologically frustrated non-diffusive dynamical state, coacervate gel composites, and macromolecular memory in hydrogels, by combining light scattering, neutron scattering, impedance spectroscopy, rheology, single molecule electrophoresis, statistical mechanics, field theory, and several simulation techniques. Specifically, the proposal addresses (a) topologically frustrated non-diffusive polymer dynamical state and its boundaries with the entropic barrier and reptation regimes, (b) phase diagrams, structure and hierarchical dynamics in coacervate gel composites, (c) electrical conductivity of gel composites, and (d) memory in hydrogels. This proposal is aimed at understanding charged hydrogel composites under severe non-equilibrium conditions, and discovering new conceptual models for polyelectrolyte transport and memory 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 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.

非技术概述由携带电荷的单体制成的大分子在所有生物体中普遍存在，并继续催化现代水基材料的配方。对这种分散在电解质水溶液中的带电大分子的行为的基本理解仍然是一个挑战。挑战的起源在于这样一个事实，即这些分子并不像单独的分子那样自行行为，而是在整个集体系统的很大距离上相互关联。因此，带电大分子的性质充满了挑战，没有足够的概念框架来理解其丰富的现象学。事实上，对这种强相关的大分子的基本理解的形成仍然是物理和生物科学中最困难的课题之一。然而，这样一个基本的理解是至关重要的，成功地设计新材料的分离科学，高吸水性的商品，药物输送，水基电导体和存储设备，除了合理化丰富的现象已经积累了几十年。PI建议制定一个基本的理解如何带电的大分子在电解质溶液中移动，或在凝胶内，或从一个区域到另一个区域，通过由于拥挤的干预障碍，以及如何赋予大分子记忆效应在水基系统。除了推动带电大分子领域的发展外，拟议的活动还包括大力支持多样性和培训新一代学者，使他们能够在未来参与价值数十亿美元的水基材料行业。技术概述PI提出了实验和理论发展，以研究微扰动力学，微扰动力学，拓扑受挫非扩散动力学状态，凝聚层凝胶复合材料和水凝胶中的大分子记忆，通过结合光散射、中子散射、阻抗谱、流变学、单分子电泳、统计力学、场论和几种模拟技术。具体而言，该建议解决（a）拓扑受挫的非扩散聚合物动态状态及其边界的熵垒和爬行制度，（B）相图，结构和分级动态凝聚凝胶复合材料，（c）凝胶复合材料的导电性，和（d）在水凝胶的记忆。该建议旨在了解严重非平衡条件下的带电水凝胶复合材料，并发现新的概念模型，在含水带电聚合物系统中的电荷传输和记忆。对这类重要材料的行为的基本理解将有助于设计新型水基聚合物材料，从而提高社会效益。该奖项反映了NSF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。

项目成果

Entropic barrier of topologically immobilized DNA in hydrogels

• DOI: 10.1073/pnas.2106380118
• 发表时间: 2021-07-13
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Chen, Kuo;Muthukumar, Murugappan
• 通讯作者: Muthukumar, Murugappan

Boundaries of the Topologically Frustrated Dynamical State in Polymer Dynamics

聚合物动力学中拓扑受阻动力学状态的边界

• DOI: 10.1021/acsmacrolett.2c00019
• 发表时间: 2022
• 期刊: ACS Macro Letters
• 影响因子: 7.015
• 作者: Chen, Kuo;Li, Siao-Fong;Muthukumar, M.
• 通讯作者: Muthukumar, M.

Electrostatically Driven Topological Freezing of Polymer Diffusion at Intermediate Confinements

• DOI: 10.1103/physrevlett.126.057802
• 发表时间: 2021-02-03
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Jia, Di;Muthukumar, Murugappan
• 通讯作者: Muthukumar, Murugappan