Nanostructured Block Copolymer/Ionic Liquid Composite Materials

离子液体表现出许多吸引人的性质，包括化学和热稳定性、消失的蒸气压、可调的溶剂化、高离子电导率和高介电常数，这使得它们作为塑料电子器件、电池、燃料电池、气体分离膜和致动器中的关键成分而吸引人。为了在应用中实现这些性质，有必要使材料固化，和/或将离子液体限制在期望的纳米结构内。嵌段共聚物提供了前所未有的灵活性，可以在1100纳米的长度范围内直接自组装，同时提供机械完整性。将进行五个不同的子项目，其范围从非常稀的溶液到几乎纯的聚合物，并且旨在从根本上了解如何利用聚合物/离子液体相互作用来制备功能材料。具体而言，本研究将：（i）扩展胶束穿梭的概念，由此共聚物聚集体在水相和离子液体相之间可逆地和完整地转移，以制备在规定温度下装载、转移和释放货物的系统，并制备用于均相催化的纳米乳液;（ii）通过三嵌段和多嵌段共聚物自组装制备坚固的离子凝胶，由此在可调温度下或在光刺激下发生凝胶化和熔融;（iv）产生具有离子液体通道的机械坚固的有序嵌段共聚物膜，用于各向同性和各向异性的高离子电导率和传输;（v）通过离子液体中的氢键作用，产生弛豫时间在相当宽的范围内可调的超分子聚合物。非技术概述本项目的目标是通过将离子液体与嵌段共聚物相结合，产生一类新的功能性纳米结构材料。含有聚合物和离子液体的材料在广泛的技术平台上具有潜在的用途，包括塑料电子器件、致动器、传感器、电池、燃料电池和分离膜。对于应用，同时优化几种性能，如高离子传输，机械完整性和易于加工，是必不可少的;这可以通过控制纳米级的材料结构来实现。离子液体作为化学转化的绿色溶剂已经在欧洲的商业实践中;嵌段共聚物表面活性剂应该大大扩展可以使用的试剂、产品和催化剂的范围。在这个项目中工作的研究生将接受聚合物合成和先进表征技术的广泛培训，并将有机会指导有才华的本科生进行研究。来自双子城的高中生，特别是女性和代表性不足的少数民族，将接触到聚合物科学，作为与技术研究所教育计划中心管理的“探索职业”夏令营的一部分。来自美国各地学院和大学的教师和学生将在PI的实验室中花费时间，通过新建立的材料研究设施网络利用一个或多个实验设施。

TECHNICAL SUMMARY Ionic liquids exhibit many appealing properties, including chemical and thermal stability, vanishing vapor pressure, tunable solvation, high ionic conductivity, and high dielectric constant, that render them appealing as key ingredients in plastic electronics, batteries, fuel cells, gas separation membranes, and actuators. To realize these properties in applications, it is necessary to solidify the material, and/or to confine the ionic liquid within a desired nanostructure. Block copolymers offer unprecedented flexibility to direct self-assembly over lengthscales from 1100 nanometers, while simultaneously providing mechanical integrity. Five different sub-projects will be pursued, that collectively range from very dilute solutions to almost pure polymer, and that are aimed at a fundamental understanding of how polymer/ionic liquid interactions can be utilized to prepare functional materials. Specifically, this research will: (i) extend the concept of the micelle shuttle, whereby copolymer aggregates transfer reversibly and intact between aqueous and ionic liquid phases, to prepare systems that load, transfer, and release cargo at prescribed temperatures, and to prepare nanoemulsions for use in homogenous catalysis; (ii) prepare robust ion gels by tri- and multiblock copolymer self-assembly, whereby gelation and melting occur at tunable temperatures or under optical stimulation; (iii) optimize the use of ion gels as gate dielectric materials in organic transistors, for plastic electronic applications; (iv) create mechanically robust, ordered block copolymer membranes with ionic liquid channels for high ionic conductivity and transport, both isotropic and anisotropic; (v) create supramolecular polymers with relaxation times tunable over a remarkably wide range via hydrogen bonding in ionic liquids.NON-TECHNICAL SUMMARYThe goal of this project is to create a new class of functional nanostructured materials by combining ionic liquids with block copolymers. Materials containing polymers and ionic liquids are potentially useful across a wide spectrum of technology platforms, including plastic electronics, actuators, sensors, batteries, fuel cells, and separation membranes. For applications the simultaneous optimization of several properties, such as high ionic transport, mechanical integrity, and facile processing, is essential; this can be achieved through controlling the material structure at the nanoscale. Ionic liquids are already in commercial practice in Europe as green solvents for chemical transformations; block copolymer surfactants should greatly extend the range of reagents, products, and catalysts that can be employed. Graduate students working in this project will be broadly trained in polymer synthesis and advanced characterization techniques, and will have the opportunity to mentor talented undergraduates in research. High school students from the greater Twin Cities, particularly females and underrepresented minorities, will be exposed to polymer science as part of an "Exploring Careers" summer camp administered with the Institute of Technology Center for Educational Programs. Faculty and students from colleges and universities across the US will spend time in the PI's laboratories to utilize one or more of the experimental facilities, through the newly-forged Materials Research Facilities Network.