CAREER: Impact of Flow-Induced Chain Alignment in Melt-Processed Complementary Semiconducting Polymer Blends

非技术概述：半导体聚合物是一类特殊的大分子，可以传导电流，吸收或发射光。这些聚合物广泛用于电子器件，包括发光二极管、太阳能电池、晶体管和许多其他器件。这个CAREER项目关注的是可熔融加工的半导体聚合物，与目前溶液加工聚合物（通常涉及有毒和对环境有害的溶剂进行加工）的焦点不同。具体来说，该研究旨在探索、理解和优化熔融加工半导体聚合物共混物的流动诱导取向及其对机械和电子性能的影响。这个项目的成功实施可能会为有机电子产品带来一个更绿色、更可持续的未来。CAREER计划的教育目标是在普渡大学建立一个充满活力的聚合物项目，以培养下一代聚合物化学家，并提高公众对聚合物科学和工程的认识。具体来说，PI将把聚合物化学和实验室整合到本科和研究生课程中，并与当地高中合作组织圣母大学-普度大学软物质和聚合物年度研讨会。此外，PI计划采用新的技术工具（即K-12学生和公众现在更喜欢与之互动的交互式在线应用程序）进行外展活动。技术概述：CAREER提案旨在了解流动诱导链排列的本质和由此产生的形态及其对熔融加工互补半导体聚合物共混物（c-SPBs）的光学、电子和机械性能的影响。流动诱导结晶一直是传统（绝缘）聚合物加工中的一个重要课题，但在半导体聚合物熔体中却鲜为人知。在本项目中，PI将制作可熔化加工的c- spb，并研究流动诱导的结构形成，以建立结构-性能-加工关系。在项目的第一阶段，PI将合成各种半导体聚合物，这些聚合物可以在所需的温度下熔化。第二阶段关注的是通过原位流变光学和流变x射线技术以及其他形态学工具来阐明聚合物熔体中流动诱导取向结构和薄膜形态的本质。第三阶段的目的是将流动诱导的形态与其在排列纤维或聚合物共混物薄膜中的电子和机械性能联系起来。本项目旨在：1)理顺可熔融加工半导体聚合物的分子设计原理；2)揭示流动诱导结晶在聚合物薄膜形态发展中的作用；3)提供流动诱导形态与重要材料性能之间的基本相关性。该项目的长期目标是开发高性能可熔融加工的c- spb，并为未来的有机电子产品提供半导体聚合物的熔融加工，以补充或优于当前的溶液加工方法。

NON-TECHNICAL SUMMARY: Semiconducting polymers are a special class of macromolecules that can conduct electrical currents and absorb or emit light. These polymers are used in a wide range of electronic devices, including light-emitting diodes, solar cells, transistors, and many others. This CAREER project is concerned with melt-processable semiconducting polymers, a departure from the current focus of solution-processed polymers (which usually involve toxic and environmentally harmful solvents for processing). Specifically, the proposal research is to explore, understand, and optimize flow-induced orientation in melt-processed semiconducting polymer blends and its impact on mechanical and electronic properties. Successful execution of this project could lead to a greener and more sustainable future for organic electronics. The educational objective of the CAREER plan is to build a dynamic polymer program at Purdue University for educating next generation polymer chemists, as well as for raising the public awareness about polymer science and engineering. Specifically, the PI will integrate polymer chemistry and laboratory into undergraduate and graduate curricula, and organize the Notre Dame - Purdue Annual Symposium on Soft Matter and Polymers in collaboration with local high schools. Further, the PI plans to adapt new technological tools (i.e. interactive online Apps that K-12 students and the general public nowadays prefer to interact with) for outreach activities. TECHNICAL SUMMARY: The CAREER proposal seeks to understand the nature of flow-induced chain alignment and the resulting morphology and its impact on optical, electronic and mechanical properties in melt-processed complementary semiconducting polymer blends (c-SPBs). Flow-induced crystallization has long been an important subject in conventional (insulating) polymer processing, but little is known in a semiconducting polymer melt. In this project, the PI will make melt-processable c-SPBs and study flow-induced structure formation in order to establish the structure-property-processing relationship. In phase I of the project, the PI will synthesize a wide range of semiconducting polymers that can be melted at desired temperatures. Phase II is concerned with elucidating the nature of flow-induced oriented structures and thin-film morphologies in polymer melts by in-situ rheo-optical and rheo-X-ray techniques, among other morphological tools. Phase III is aimed to correlate flow-induced morphologies with their electronic and mechanical properties in aligned fibers or thin films of polymer blends. This project aims to: 1) rationalize the molecular design principles for melt-processable semiconducting polymers, 2) reveal the role of flow-induced crystallization in polymer thin-film morphology development, and 3) offer a fundamental correlation between flow-induced morphologies and important materials properties. The long-term goal of this project is to develop high-performance melt-processable c-SPBs and enable melt-processing of semiconducting polymers for future organic electronics, complementary to or advantageous over current solution-processed approaches.