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Transient Network Theory: Bridging Molecular Mechanisms to the Viscoelasticity of Soft Polymers

瞬态网络理论：将分子机制与软聚合物的粘弹性联系起来

基本信息

批准号：
1761918
负责人：
Franck Vernerey
金额：
$ 39.89万
依托单位：
University of Colorado at Boulder
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-01 至 2023-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1761918&HistoricalAwards=false
关键词：
Transient Network Theory Bridging Molecular

项目摘要

The ability to organize large populations of molecules into materials can open the door to making dynamic materials or soft machines, thus advancing the national health, prosperity, and welfare; and even securing the national defense by facilitating the emerging area of soft robotics. Such materials are often found in nature in the form of transient polymeric networks which are at the source of muscle contraction as well as self-healing and adaptation in biological tissues. Although similar molecular networks can be synthesized in the laboratory, their performance still lags far behind their biological counterparts; raising the need for a better theoretical understanding and experimental control. This project will provide a route to fundamentally understand how the organization and dynamics of such polymer networks can lead to a well-targeted emerging response. It will promote the progress of soft matter science by bridging the gap between our understanding of the behavior of a single molecule and that of an entire network, not only enabling a fundamental understanding of bio-polymers, but also in improving our ability to control synthetic materials. The project will also develop an educational program around the concept of "materials of the future and bio-inspiration" in high-schools, the enhancement of undergraduate curriculum, and dissemination of scientific knowledge through social media.From a fundamental viewpoint, this project will support the development of a transient network theory that will describe, in a statistical sense, the time evolution of a transient polymer network based on molecular processes such as chain detachment, reputation, or diffusion. Going beyond phenomenological viscoelastic models, key concepts in statistical mechanics will be used to obtain a clearer connection between transient molecular interactions between many polymer chains and the time-dependent response of the network. The project brings three key contributions: (a) a new fundamental understanding of the relation between molecular processes and rheology, elasticity and energy dissipation; (b) the ability to generate new hypotheses regarding dynamic polymers and explore their macroscopic outcome in terms of growth, fracture resistance, and self-healing, and (c) a new continuum framework to describe the extreme deformation of soft materials whose behavior lies between that of solids and fluids. A computational methodology based on finite elements will be introduced to solve the research theory and used to study and characterize the viscoelastic response of synthetic and biopolymers in terms of their inner structure.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.

将大量分子组织成材料的能力可以为制造动态材料或软机器打开大门，从而促进国家健康，繁荣和福利;甚至通过促进软机器人的新兴领域来确保国防。这种材料在自然界中通常以瞬时聚合物网络的形式存在，其是生物组织中肌肉收缩以及自我愈合和适应的来源。虽然类似的分子网络可以在实验室中合成，但它们的性能仍然远远落后于生物学上的同类，因此需要更好的理论理解和实验控制。该项目将提供一条路线，从根本上了解这种聚合物网络的组织和动力学如何导致有针对性的新兴反应。它将通过弥合我们对单个分子行为和整个网络行为的理解之间的差距，促进软物质科学的进步，不仅能够从根本上理解生物聚合物，而且还可以提高我们控制合成材料的能力。该项目还将围绕高中“未来材料和生物灵感”的概念，加强本科课程，通过社交媒体传播科学知识，开发教育计划。从根本上看，该项目将支持瞬态网络理论的开发，该理论将从统计意义上描述，基于分子过程（如链分离、信誉或扩散）的瞬态聚合物网络的时间演化。超越唯象粘弹性模型，统计力学中的关键概念将用于获得许多聚合物链之间的瞬态分子相互作用和网络的时间依赖性响应之间的更清晰的联系。该项目带来了三个关键贡献：（a）对分子过程与流变学、弹性和能量耗散之间的关系有了新的基本认识;（B）产生关于动态聚合物的新假设并探索它们在生长、抗断裂性和自修复方面的宏观结果的能力，（c）一个新的连续体框架来描述软材料的极端变形，其行为介于固体和流体之间。将引入基于有限元的计算方法来解决研究理论，并用于研究和表征合成聚合物和生物聚合物的内部结构的粘弹响应。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。