CAREER: Development of Force-Activated Materials for the Release of Small Organic Molecules

材料环境中的大的、可观察到的变化可以转化为分子尺度的事件，在最小的尺度上引起化学反应。在宏观和分子水平的事件之间进行沟通的一个特别强大的方法是可以由机械力驱动的化学反应的发展。为此，PI寻求开发能够将机械应力（如压缩和伸长）转化为化学输出（包括释放小分子试剂）的材料。被释放的小分子可以应用于治疗剂、催化剂或试剂，从而在药物递送、自增强材料和传感器等不同领域提供进步。化学系的本科生和研究生将在该计划中得到指导，并将有机会与化学，工程和物理学科的专家合作。PI还将整合一个教育计划，其中包括该计划研究部分的发现和挑战。这将通过与当地一所高中建立伙伴关系来实现，以开发大学研究人员和高中学生之间的合作模式。这一过程将包括重新设计高中科学课程，以包括基于问题的学习活动，模仿大学本科和研究生研究人员的经验。预期的成果包括增加招聘和保留的学生从代表性不足的少数群体在科学，技术，工程，和Mathematics majores.Technical摘要：该计划的目的是开发能够通过机械化学转导释放小有机分子的材料。通过这种方式，宏观力将转化为分子水平的化学反应，导致引发共价键断裂。为此，PI将研究和比较机械反应官能团的互补异构体设计（即，机械基团），其通过键弯曲或拉伸变形而被激活。一个中心假设是，这两种激活模式将表现出不同的能量转导效率。此外，固态机械性能最适合于激活每种机械基团类型将进行探讨。这些信息将有助于指导未来的机械载体的设计，特别是那些能够释放小分子试剂，而不会引起聚合物主链内的键断裂。PI还寻求开发能够将单个位点特异性机械化学事件的响应放大为多个小分子级联释放的材料。这将通过开发能够触发自分解聚合物的头到尾解聚的机械载体来实现。这项研究的结果将是更深入地了解特定的激活机制如何影响机械效率，以及放大单个机械激活输出的能力。这些研究工作将直接与高中理科学生和大学研究人员之间合作的教育计划相结合。具体来说，PI将与当地高中的成员合作，设计一个以基于问题的学习为中心的科学课程。PI的研究团队的成员将帮助设计和实施课程和实验室经验，模仿本科生和研究生的化学研究人员的经验。

NON-TECHNICAL SUMMARY:Large, observable changes in a material environment can be translated into molecular-scale events, giving rise to chemical reactions at the smallest length scales. A particularly powerful method for communicating between macroscopic and molecular-level events is the development of chemical reactions that can be driven by mechanical force. Toward this end, the PI seeks to develop materials capable of converting mechanical stress, such as compression and elongation, into chemical outputs including the release of small molecule agents. The small molecules that are released may be applicable to therapeutics, catalysts, or reagents, providing advancements in diverse areas such as drug delivery, self-reinforcing materials, and sensors. Undergraduates and graduate students in the Department of Chemistry will be mentored in this program, and will have opportunities to collaborate with experts from chemistry, engineering, and physics disciplines. The PI will also integrate an education plan that incorporates the discoveries and challenges from the research component of the program. This will be achieved through partnership with a local area high school to develop a model for collaboration between university researchers and high school students. The process will include redesigning high school science curricula to include problem-based learning activities that mimic the experiences of undergraduate and graduate researchers at the university level. Anticipated outcomes include increased recruitment and retention of students from underrepresented minority groups in Science, Technology, Engineering, and Mathematics majors.TECHNICAL SUMMARY:This program aims to develop materials capable of releasing small organic molecules via mechanochemical transduction. In this way, macroscopic forces will be translated into molecular-level chemical reactions resulting in triggered covalent bond scission. Toward this end, the PI will investigate and compare complementary isomeric designs for mechanoresponsive functional groups (i.e., mechanophores) that are activated by either bond bending or stretching distortions. A central hypothesis is that these two modes of activation will manifest different efficiencies of energy transduction. Additionally, the solid-state mechanical properties best suited for activation of each mechanophore type will be explored. This information will be useful in guiding future designs of mechanophores, particularly those capable of releasing small molecule agents without incurring bond scission within the polymer main chains. The PI also seeks to develop materials capable of amplifying the response of a single, site-specific mechanochemical event into a cascade release of multiple small molecules. This will be achieved through the development of mechanophores capable of triggering head-to-tail depolymerization of self-immolative polymers. The outcomes of this research will be a deeper understanding of how specific activation mechanisms influence mechanophore efficiency, and the ability to amplify the output from single mechanophore activation. These research efforts will be directly integrated with an education plan for collaboration between high school science students and university researchers. Specifically, the PI will work with members of a local area high school to design a science curriculum centered on problem-based learning. Members of the PI's research team will help design and implement coursework and lab experiences that mimic the experiences of undergraduate and graduate researchers in chemistry.