Functional Elastomers Based on Bottlebrush-Shaped Macromolecules

非技术概述：高度柔软和有弹性的材料用于重建手术、细胞分化和防污表面。该项目的目标是通过构建瓶刷状大分子聚合物网络来设计无溶剂超软材料。新材料将具有相对于多组分聚合物凝胶的主要优势，这些聚合物凝胶易于分离和逃逸构成液体。此外，瓶刷结构允许丰富的特定化学功能的结合，提供新的能力，如形状控制、成像对比和对外部刺激的反应。研究将集中在先进大分子结构的合成和分子瓶刷的层次结构与力学性能（如刚度、弹性和韧性）之间的结构-性能关系的基本理解。该项目可能会导致提供大量功能和刺激反应的新型材料，实现可编程形状转换和生物组织内植入物的非侵入性操作。此外，跨学科研究将确保基于学生和博士后研究人员的多学科培训，与高中的伙伴关系以及科学和技术中代表性不足的群体的参与，最大限度地整合科学和教育。技术概述：该项目专注于设计具有独特组合特性的新型功能材料：整齐的化学成分、极低的弹性模量、可编程的形状和声学响应。具体来说，该研究将探索由瓶刷状聚合物构成的弹性体，这些聚合物在其侧链和骨架中含有可结晶和氢键部分。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由晶体和氢键组成的临时支架组成的精细交织结构，从而在前所未有的范围内实现对机械性能和物体形状的刺激响应控制。瓶刷弹性体的独特机械性能源于其分层结构，其中共价和排除的体积结构约束在不同长度尺度上放大和指导分子力。对分子力和超分子约束之间的层次关系的基本理解及其对材料性能的影响代表了该项目的核心智力挑战。展望实际应用，该研究将探索瓶刷弹性体的潜力，以创造可在生物组织内无创和远程导航和激活的可变形植入物。这个跨学科的研究项目将通过对学生和博士后的跨学科培训、与高中的合作以及在科学和技术领域未被充分代表的群体的参与，确保最大限度地整合科学和教育。

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.