CAREER: SusChEM: Engineering Molecular Interactions to Control Ion Transport in Hydrated Polymers for Membrane Separations

在未来十年内，可能需要从含盐和受污染的水中去除盐来缓解美国的水资源短缺。此外，从农业径流中去除氮和磷可以防止富营养化，并修复墨西哥湾的“死区”。此外，可能会开发新的路线来回收稀有金属，这些金属在美国供不应求，受到出口管制，但却是军事应用和电子产品所需的磁铁和传感器组件。这三个技术挑战——海水淡化、营养物回收和稀有金属回收——都涉及从水中去除带电分子（离子）。要将这些离子从水中分离出来，需要选择性的材料，比如膜，它允许一种分子通过，而禁止其他分子通过。使分离所需的能量最小化，增加了经济可行性。虽然目前的膜根据大小和/或电荷来分离分子，但它们目前不能区分带相似电荷的离子。这个CAREER项目将设计和合成新的分子定制聚合物膜，创造独特的电化学环境，选择性地区分类似电荷、大小和其他性质的离子。本项目将阐明离子性质、分子约束和带电基团极性对带电聚合物膜中离子传输的影响。基本的结构-性质关系将发展为单一电解质，并扩展到离子混合物。这些关系将用于在带电膜的有限纳米空间中定制电化学环境，从而为合理设计先进的聚合物材料奠定基础。新膜的化学结构和形态将实现高离子选择性，并最大限度地减少离子分离过程的能量消耗。将讨论膜的机械和化学稳定性。综合教育计划通过为高中生提供实习，为高中教师提供讲习班，传播基于网络的膜性能计算器，将该计算器纳入本科课程，对本科生和研究生进行直接实验室培训，以及广泛传播研究成果，将研究成果纳入各级工程教育。综合研究和教育计划将导致强大的膜来解决全球水和能源资源，这是食品-能源-水关系挑战的核心。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Within the next decade, the removal of salt from salty and contaminated water may be needed to alleviate water shortages in the USA. Also, removal of nitrogen and phosphorus from agricultural runoff may be implemented to prevent eutrophication and remediate a "dead zone" in the Gulf of Mexico. Additionally, novel routes may be developed to recover rare metals that are in short supply in the USA, and subject to export controls, yet are required components of magnets and sensors for military applications and electronics. These three technological challenges--desalination, nutrient recovery, and rare metal recovery--all involve the removal of charged molecules (ions) from water. To separate these ions from water requires selective materials, such as membranes, that allow one type of molecule to pass, while prohibiting others. Minimization of the energy required for the separation increases economic viability. Although current membranes separate molecules based on size and/or charge, they do not currently discriminate between similarly charged ions. This CAREER project will design and synthesize new molecularly-tailored polymer membranes that create unique electrochemical environments to selectively discriminate ions of similar charge, size, and other properties. This project will elucidate the influence of ion properties, molecular confinement, and the polarity of charged groups on ion transport in charged polymer membranes. Fundamental structure-property relationships will be developed for single electrolytes, and extended to ion mixtures. These relationships will be used to tailor the electrochemical environment in the confined nano-space of charged membranes, thereby laying the foundation for rational design of advanced polymeric materials. The chemical structures and morphologies of the new membranes will enable high ion selectivity, and minimize energy consumption of ion separation processes. The mechanical and chemical stability of the membranes will be addressed. An integrated educational plan incorporates the research outcomes into all levels of engineering education, by providing internships for high school students, workshops for high school teachers, dissemination of a web-based membrane performance calculator, incorporation of this calculator into undergraduate courses, direct laboratory training of undergraduate and graduate students, and broad dissemination of research results. The integrated research and education plan will lead to robust membranes to address global water and energy resources that lie at the heart of food-energy-water nexus challenges.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.