Responsive and Healable Materials Constructed via Dynamic-Covalent Bonds

非技术总结：这个项目将测试这样一个假设，即动态相互作用可以用于制备在溶液中或在块状状态下可逆组装和拆卸的材料。将考虑两种特定类别的材料。第一个系统将涉及纳米级聚合组件，当周围溶液中有高浓度糖时，可以触发这些组件进行分解。如果这些组件可以装载分子货物，这种材料可能会被证明对糖诱导的胰岛素释放或其他疗法有用。第二个要研究的系统将由大量塑料或类似弹性体的材料组成，这些材料在被撕裂、划伤或破碎后能够愈合。可自我修复的材料可用于各种应用，包括用于医疗器械、涂层和弹性体。这两类被研究的材料都将从本项目中综合方法引入的设计和建筑结构中获得它们的适应性和健全性。除了开发新材料，研究其潜在的化学和物理性质，并考虑到这些材料的潜在用途外，这项研究还将有助于在一个本质上是多学科的领域中教育和培训多个层面的科学家。技术概述：这项研究计划旨在开发响应性聚合物材料领域中的硼酸/硼酸酯可逆性。这项研究的主要假设是，在两类材料中，硼/硼酸酯交联物的动态共价性质可以用来实现刺激响应和自我修复行为。第一类材料是由通过硼酸酯交联的聚合物囊泡组成的。具有一个亲水嵌段和一个含硼酸嵌段的嵌段共聚物将与一种多功能二醇自组装和交联，该二醇在高浓度的糖和其他小分子二醇的作用下可以被诱导解离。要研究的第二类材料包括通过硼酸酯交联的大块聚合物材料。当材料失效时，可通过在损伤界面交换硼酸酯来诱导愈合。虽然这一现象已被用于小分子有机合成、分子识别和糖类传感，但它在材料设计和受控聚合物合成领域的应用受到了极大的限制。自主自愈的材料可用于各种应用，包括用于医疗器械、涂料和弹性体。参与这个项目的研究生将对可逆共价和自我修复材料的新兴领域获得宝贵的见解。外展工作将是这一项目的一个关键组成部分，将使地区高中和社区大学的学生接触到这些领域的研究。

NON-TECHNICAL SUMMARY: This project will test the hypothesis that dynamic interactions can be used to prepare materials that reversibly assemble and disassemble in solution or in the bulk state. Two specific classes of materials will be considered. The first system will involve nanosized polymeric assemblies that can be triggered to disassemble when high concentrations of sugar are in the surrounding solution. Provided these assemblies can be loaded with molecular cargo, such materials may prove useful for the sugar-induced release of insulin or other therapeutics. The second system to be investigated will consist of bulk plastic or elastomer-like materials capable of healing after being torn, scratched, or broken. Materials that self-heal may find utility in a variety of applications, including being used in medical devices, coatings, and elastomers. Both classes of materials to be studied will derive their adaptability and healability from the design and architectural structure introduced by the synthetic approach in this project. In addition to the development of new materials, studying their underlying chemical and physical properties, and considering the potential utility of these materials, this research will help to educate and train scientists at many levels in a field that is inherently multidisciplinary. TECHNICAL SUMMARY: This research plan is designed to exploit boronic/boronate ester reversibility within the field of responsive polymeric materials. The main hypothesis of the proposed research is that the dynamic-covalent nature of boronic/boronate ester crosslinks can be utilized to achieve stimuli-responsive and self-healing behaviors in two classes of materials. The first class of materials is composed of polymeric vesicles crosslinked via boronic esters. Block copolymers with one hydrophilic block and one boronic acid-containing block will be self-assembled and crosslinked with a multifunctional diol that can be induced to dissociate under high concentrations of sugars and other small molecule diols. The second class of materials to be investigated consists of bulk polymeric materials crosslinked via boronic esters. Upon material failure, healing can be induced by boronic ester exchange at the damage interface. While this phenomenon has been employed for small molecule organic synthesis, molecular recognition, and saccharide sensing, its incorporation in the fields of materials design and controlled polymer synthesis has been significantly limited. Materials that autonomously self-heal may find utility in a variety of applications, including being used in medical devices, coatings, and elastomers. Graduate students involved in this project will gain valuable insight into the emerging fields of reversible-covalent and self-healing materials. Outreach efforts will be a key component of this project and will involve exposure of area high school and community college students to research in these areas.