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CAREER: Photocontrolled Dynamic Covalent Crosslinkers for Light-Responsive Polymer Networks

职业：用于光响应聚合物网络的光控动态共价交联剂

基本信息

批准号：
1847948
负责人：
Julia Kalow
金额：
$ 70万
依托单位：
Northwestern University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-05-15 至 2025-04-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1847948&HistoricalAwards=false
关键词：
CAREER Photocontrolled Dynamic Covalent Crosslinkers

项目摘要

Polymers that respond to external cues with changes in their physical properties can serve as sensors, actuators, controlled delivery systems, tissue mimics, and healable materials. Light is one of the most appealing stimuli because it can be delivered remotely with precise control over space, time, intensity, and color. The research group of Professor Julia Kalow at Northwestern University studies how light can be used to control the formation and breakage of reversible chemical bonds in polymers. When these photoswitchable chemical bonds are used to link polymer strands, the resulting polymer networks exhibit reversibly-controlled changes in properties, such as stiffness and adaptability. The novel materials and insights from this research help to create the next generation of high-performance, re-processable polymers. Additionally, the polymer materials may mimic tissue mechanics, acting as user-controlled matrixes to study biological processes like muscle contraction and to build synthetic organs. The broader impacts expand the exposure of students with visual impairment to STEM. The educational program develops assistive technologies for visually impaired students and their teachers. Students with visual impairment are often left out of traditional outreach activities and laboratory experiences. Professor Kalow's team works to fully include these students in STEM as the newly created polymer materials are used to create assistive tactile displays.With the support of the Macromolecular, Supramolecular, and Nanochemistry program of the Division of Chemistry, the Kalow group prepares new photoswitches and elucidates how control is translated from the molecular to macroscopic level. This fundamental research combines physical organic techniques, synthesis, and mechanical characterization to study three distinct mechanisms for photoswitching dynamic covalent crosslinkers: crosslink stability, crosslink exchange rate, and crosslink topology. The research aims to marry photoswitch conformation and dynamic covalent bonds to achieve dramatic and reversible physical changes in soft materials. The expected outcomes of the research are the development of new photoswitches containing dynamic covalent bonds, improvement in the reversibly photocontrolled gels, elastomers, and vitrimers, and increased fundamental insight into the relationship between molecular reactivity and viscoelasticity.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.

通过改变其物理性质来响应外部提示的聚合物可以用作传感器、致动器、受控输送系统、组织模拟物和可愈合材料。光是最吸引人的刺激之一，因为它可以通过精确控制空间，时间，强度和颜色来远程传输。西北大学的Julia Kalow教授的研究小组研究了如何利用光来控制聚合物中可逆化学键的形成和断裂。当这些可光转换的化学键用于连接聚合物链时，所得的聚合物网络表现出可逆控制的性质变化，例如刚度和适应性。这项研究的新材料和见解有助于创造下一代高性能、可再加工的聚合物。此外，聚合物材料可以模仿组织力学，作为用户控制的矩阵来研究生物过程，如肌肉收缩和建立合成器官。更广泛的影响扩大了视力障碍学生对STEM的接触。该教育方案为视障学生及其教师开发辅助技术。视力障碍的学生经常被排除在传统的外展活动和实验室体验之外。Kalow教授的团队致力于将这些学生完全纳入STEM，因为新创建的聚合物材料用于创建辅助触觉显示器。在化学系的大分子，超分子和纳米化学项目的支持下，Kalow团队制备了新的光开关，并阐明了控制如何从分子水平转化为宏观水平。这项基础研究结合了物理有机技术，合成和机械表征，研究三种不同的机制，光开关动态共价交联剂：交联稳定性，交联交换率和交联拓扑结构。该研究旨在将光开关构象和动态共价键结合起来，以实现软材料中戏剧性和可逆的物理变化。该研究的预期成果是开发含有动态共价键的新型光开关，改进可逆光控凝胶、弹性体和玻璃化物，以及增加对分子反应性和粘弹性之间关系的基本认识。该奖项反映了NSF的法定使命，并被认为值得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来支持。