Functional Elastomers Based on Bottlebrush-Shaped Macromolecules

基于刷子状高分子的功能弹性体

• 批准号: 1407645
• 负责人: Sergei Sheiko
• 金额: $ 52万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1407645&HistoricalAwards=false
• 关键词: Functional; Elastomers; Based; Bottlebrush; Shaped

NON-TECHNICAL SUMMARY:Highly soft and elastic materials are desired for uses in reconstructive surgery, cell differentiation, and antifouling surfaces. The project goal is to design solvent-free ultra-soft materials by constructing polymer networks of bottlebrush-shaped macromolecules. The new materials will possess a major advantage with respect to multicomponent polymer gels that are prone to segregation and escape of constituting liquids. In addition, the bottlebrush architecture allows abundant incorporation of specific chemical functionalities that provide new abilities such as shape control, imaging contrast, and response to external stimuli. The research will focus on the synthesis of advanced macromolecular architectures and fundamental understanding of the structure-property relations between the hierarchical structure of molecular bottlebrushes and mechanical properties such as stiffness, elasticity, and toughness. This project may lead to novel materials that offer a vast array of functions and stimuli responses enabling programmable shape transformations and non-invasive manipulation of implants within biological tissue. Moreover, the interdisciplinary research will ensure maximum opportunity for integrating science and education based on the multidisciplinary training of students and postdoctoral researchers, partnerships with high schools, and involvement of underrepresented groups in science and technology.TECHNICAL SUMMARY:The project is focused on the design of novel functional materials possessing a unique combination of properties: neat chemical composition, exceptionally low elastic modulus, programmable shape, and acoustic response. Specifically, the research will explore elastomers constructed of bottlebrush-shaped polymers that contain crystallizable and H-bonding moieties in their side-chains and backbones. Through molecularly constrained crystallization and abundant chain-end functionalities, finely interwoven structures composed of a permanent covalent network and a temporary scaffold of crystallites and hydrogen bonds will be created to enable stimulus-responsive control of mechanical properties and object shapes in an unprecedented range. The unique mechanical properties of bottlebrush elastomers stem from the hierarchical structure, wherein covalent and excluded volume architectural constraints amplify and direct molecular forces at different length scales. Fundamental understanding of the hierarchical relation between molecular forces and supramolecular constraints, and its impact on material properties represents the core intellectual challenge of the project. Looking towards practical applications, the research will explore the potential of bottlebrush elastomers for creation of shape-changing implants that can be navigated and activated inside a biological tissue non-invasively and remotely. This interdisciplinary research project will ensure maximum opportunity for integrating science and education based on the interdisciplinary training of students and postdoctoral associates, partnerships with high schools, and involvement of underrepresented groups in science and technology.

非技术概述：重建手术、细胞分化和防污垢表面需要高度柔软和有弹性的材料。该项目的目标是通过构建瓶刷形状的大分子的聚合物网络来设计无溶剂的超软材料。新材料将拥有多组分聚合物凝胶的主要优势，因为多组分聚合物凝胶容易分离和逃逸构成液体。此外，瓶刷结构允许大量结合特定的化学功能，提供新的能力，如形状控制、成像对比度和对外部刺激的反应。这项研究将集中在合成先进的大分子结构和基本了解分子瓶刷的层次结构与机械性能之间的结构-性能关系，如刚性、弹性和韧性。该项目可能会带来提供大量功能和刺激反应的新型材料，使生物组织内的植入物能够进行可编程的形状转换和非侵入性操作。此外，跨学科研究将基于对学生和博士后研究人员的多学科培训、与高中的合作伙伴关系以及未被充分代表的群体参与科学和技术的基础上，确保最大限度地将科学和教育结合在一起。技术摘要：该项目专注于设计具有独特性能组合的新型功能材料：整齐的化学成分、极低的弹性模数、可编程的形状和声学响应。具体地说，这项研究将探索由瓶刷形状的聚合物组成的弹性体，这种聚合物的侧链和主链中含有可结晶和氢键的部分。通过分子约束结晶和丰富的链端功能，将创建由永久共价网络和晶体和氢键的临时支架组成的精细交织结构，从而能够在前所未有的范围内对机械性能和物体形状进行刺激响应控制。瓶刷弹性体独特的力学性能源于层次化结构，其中共价和排除的体积结构限制放大并指导不同长度尺度上的分子力。对分子力和超分子约束之间的等级关系及其对材料性质的影响的基本理解是该项目的核心智力挑战。展望实际应用，这项研究将探索瓶刷弹性体创造变形植入物的潜力，这种植入物可以在生物组织内非侵入性地远程导航和激活。这一跨学科研究项目将确保在对学生和博士后助理进行跨学科培训、与高中建立伙伴关系以及代表不足的群体参与科学和技术的基础上，最大限度地将科学与教育结合起来。