Asymmetric Side Chain Nanodomain-Driven Paracrystallinity Control in Conjugated Polymers

非技术概述：该项目专注于了解和改进共轭聚合物的性能，这类材料的电子导电性使其在能源产生和储存、生物和化学传感器以及计算等广泛的设备中发挥作用。这些材料的电子性能对它们的结晶程度和晶体组织的变化非常敏感；然而，目前只有有限和一般的策略来控制这种晶体组织。为了开发建立这种控制的新策略，华盛顿大学(UW)的研究人员将生产一系列具有高度可控化学结构的聚合物，这些聚合物经过专门调整以提高晶体质量。这些聚合物还将有助于了解化学结构和晶体质量之间的联系，从而更容易预测和设计未来更好的聚合物。由于清洁能源的重要性和社区的兴趣，这项工作将在许多不同的地方广泛传播。其中一个主要途径是通过在参观教室期间展示可伸缩太阳能电池来分享研究实验室的工作，以及通过UW材料大使计划参加更大的科学活动，如科学和制造商博览会。PI还将与华盛顿大学工程数学学院合作，与社区中服务不足的成员合作，为他们提供在高中毕业前参与研究实验室工作的机会。技术概述：共轭聚合物主链中的准结晶度是共轭聚合物电子传导性的一个关键限制，目前改善这一参数的策略极其有限。为了解决这个问题，华盛顿大学的研究人员试图开发一种新的聚合物主链结构，使用极性和非极性侧链的交替模式来提高聚合物主链的准晶性。具体地说，这项工作提出利用极性和非极性侧链的自分离来制备具有高侧链结晶度的聚合物。然后，这种聚合物将使用各种溶剂和热加工条件进行加工，以控制侧链结晶度的程度。对主链准晶度的影响将被测量，并与加工条件和侧链结晶度相关联。这种关联将建立对可结晶侧链与主链准晶性之间的相互联系的理解，并为利用侧链组织作为提高主链准晶性的工具的策略提供洞察。这项工作将从聚噻吩类主链开始，但将扩大到包括稠环和给体-受体共聚物。通过深入研究侧链自分离，以及加工条件、侧链结晶度和平行结晶度之间的关系，本研究将为改善共轭聚合物的性能提供策略。这一奖项反映了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:This project focuses on understanding and improving the performance of conjugated polymers, a class of materials whose electronic conductivity makes them useful in a wide range of devices across energy generation and storage, biological and chemical sensors, and computation. The electronic performance of these materials is very sensitive to changes in how crystalline they are, and how organized the crystals are; however, there are currently only limited and general strategies to control this crystal organization. To develop new strategies for building this control, researchers at the University of Washington (UW) will produce a series of polymers with a highly controlled chemical structure that is specifically tuned to improve the crystal quality. These polymers will also help to build understanding of the connection between chemical structure and crystal quality, making it easier to predict and design better polymers in the future. Because of the importance of clean energy and interest in the community, this work will be broadly communicated in a number of different places. One major pathway will be through sharing the research lab’s work by demonstrating stretchable solar cells during visitations to classrooms, as well as participating in larger science events such as science and maker fairs, through the UW Materials Ambassadors program. The PI will also work with the UW College of Engineering Math Academy, working with underserved members of the community by providing opportunities for them to participate in research lab work before even graduating from high school. TECHNICAL SUMMARY:Paracrystallinity in conjugated polymer backbones represents a critical limitation for conjugated polymer electronic conductivity, and current strategies to improve this parameter are currently extremely limited. To address this, researchers at the University of Washington seek to develop a new polymer backbone architecture, using an alternating pattern of polar and nonpolar side chains to improve polymer backbone paracrystallinity. Specifically, this work proposes to use the self-segregation of polar and nonpolar side chains to produce a polymer with high side-chain crystallinity. This polymer will then be processed using a variety of solvent and thermal processing conditions, to control the extent of side chain crystallinity. The effect on backbone paracrystallinity will be measured and correlated with the processing conditions and side-chain crystallinity. This correlation will build understanding of the interconnection between crystallizable side chains and the backbone paracrystallinity, and offer insight into the strategy of using side chain organization as a tool for improving the backbone paracrystallinity. The work will begin with polythiophene backbones but will be expanded to include fused rings and donor-acceptor copolymers. By delving into not just the side-chain self-segregation, but also the connection between processing conditions, side-chain crystallinity, and paracrystallinity, this research will provide a strategy to improving the performance of conjugated polymers. .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.