Cultivating Conjugated Polymers as Novel Light Responsive Materials

非技术概述：刺激响应材料根据其环境的变化改变其结构或性能。这项研究计划将开发新型的刺激响应型聚合物，其功能和特性可以通过光暴露来控制。这是令人兴奋的，因为光是一种“干净”的刺激，因为它可以远程施加，而不需要物理接触，很容易形成图案，其强度可以非常精确地调整。不幸的是，很少有化合物对光有反应。计划中的研究计划将提供指导这些结构变化的途径，以改善它们在功能设备中的性能，并放大这些结构变化。因此，这一研究计划的结果将扩大可以通过光曝光合理控制和图案化的应用，这将显著扩大光响应材料的实用性。通过这项研究计划，并通过让公立高中生参与实践研究体验，为应对刺激响应材料领域的重大挑战做好准备的下一代科学家和工程师的劳动力发展和培训将实现，从而为大学做好特别的准备。ORNL和NIST的国家中子设施实验的完成将产生进一步的影响，参与该项目的学生将在多用户设施中获得实践经验，并为这些国家资源的持续健康做出贡献。该项目还将在田纳西州进一步发展可持续的研究基础设施，并将实施以促进未被充分代表的群体参与研究。技术摘要：该研究计划的总体目标是提供途径，通过改变分子、纳米和介观结构来合理控制共轭聚合物的光电子性能，并提供稳健的途径来放大其光诱导的结构变化，从而实现新型的光响应材料。目前的结果清楚地表明，共轭聚合物对光子的吸收可逆地改变了它们的结构、组装和功能。因此，本研究计划将阐明共轭聚合物活性层中光诱导结构有序性与其光物理性质之间的关系。同时，将开发和利用定向共轭聚合物结构，这些结构旨在当暴露在溶液和薄膜中的光线下时，增强其结构和组装的变化，以提供具有所需特性的新的刺激响应材料的途径。这项研究计划将开发方法来放大光暴露下共轭聚合物的结构变化，并将光诱导的共轭聚合物混合物的层次结构变化与最佳功能反应相关联。这些关键信息将被用来阐明指导方针，以实现对具有目标特性的新型光响应材料的系统修改、合理设计和控制。这项研究还将尝试将光子吸收对共轭聚合物构型、组装和垂直形态的影响与共轭聚合物有源层的光电性能直接相关。这反过来可能进一步提供关键环节，以合理设计共轭聚合物解决方案或混合物以及相关的热、光和沉积处理协议，以实现具有最佳功能性能的设备。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARY:Stimuli-responsive materials alter their structure or properties according to changes in their environment. This research program will develop novel stimuli-responsive polymers whose function and properties can be controlled by light exposure. This is exciting as light is a "clean" stimulus in that it can be applied remotely without physical contact, is readily patternable, and its intensity can be tuned with great fidelity. Unfortunately, there are few compounds that are light-responsive. The planned research program will provide pathways to direct these structural changes to improve their performance in functional devices and to amplify these structural changes. The results of this research program will therefore expand the applications that can be rationally controlled and patterned by light exposure, which will significantly extend the practicality of light-responsive materials. Workforce development and training of the next generation of scientists and engineers who are prepared to tackle the grand challenges in stimuli-responsive materials will be realized through this research program and also by engaging public high school students in hands-on research experiences, thus providing exceptional preparation for college. Further impact will result from the completion of experiments at the national neutron facilities at ORNL and NIST where the students participating in this project will acquire hands-on experience in a multi-user facility and contribute to the continued health of these national resources. This project will also further develop the sustainable research infrastructure in Tennessee and will be implemented to promote the participation of underrepresented groups in research.TECHNICAL SUMMARY:The overarching goal of this research program is to provide pathways to rationally control the optoelectronic performance of conjugated polymers by altering their molecular, nanoscale, and mesoscale structure with exposure to light, as well as to provide robust routes to amplify their light-induced structural changes so as to realize novel light-responsive materials. Current results clearly show that the absorption of a photon by conjugated polymers reversibly alters their structure, assembly, and functionality. Therefore, this research program will elucidate the relationship between light-induced structural order in conjugated polymeric active layers and their photo-physical properties. In parallel, targeted conjugated polymer constructs that are designed to augment their alteration in structure and assembly when exposed to light in solutions and thin films will be developed and harnessed to provide routes to new stimuli-responsive materials with desired properties. This research program will develop methods to amplify the structural changes of conjugated polymers with exposure to light and correlate light-induced alteration of the hierarchical structure of conjugated-polymer mixtures to optimal functional response. This critical information will then be used to elucidate guidelines to enable the systematic modification, rational design and control of novel light-responsive materials with targeted properties. This research will also attempt to directly correlate the impact of photon absorption on conjugated polymer configuration, assembly, and vertical morphology to the optoelectronic performance of conjugated polymer active layers. This in turn may further provide crucial links toward the rational design of conjugated polymer solutions or blends and associated thermal, light, and deposition processing protocols so as to realize devices with optimal functional performance.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.