Enabling Tailored Selectivity of Ion-Selective Membranes with Dual-Driving Force Operation

通过双驱动力操作实现离子选择性膜的定制选择性

• 批准号: 2207238
• 负责人: Ngai Yin Yip
• 金额: $ 35万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207238&HistoricalAwards=false
• 关键词: Enabling; Tailored; Selectivity; Ion; Selective

Technologies that enable the selective separation of different ions in aqueous mixtures are required for many essential energy, water, and environmental separations processes. Ion-selective membranes (ISMs) are polymeric films with charged ionic functional groups that allow the transport of oppositely-charged species (counterions) through the membrane while retaining like-charged ions (co-ions). A driving force (electrostatic potential) is applied to transport ions through the membrane. ISMs have been used in commercial applications such as fuel cells and electrodialysis desalination, but they exhibit performance limitations that preclude their application under many industrially-relevant conditions. First, ISMs suffer from diminished selectivity between counter- and co-ions at higher electrolyte concentrations. ISMs are also unable to discriminate between counterions with the same valency. This project will investigate using a second, simultaneous driving force (hydraulic pressurization) to alter the relative permeation of different ions. By coordinating the magnitude and direction of the two driving forces, termed “dual-driving force” operation, the two shortcomings in ISM selectivity above may be overcome. The development of more selective ion separation technologies can unlock opportunities for resource recovery from nontraditional source waters, including recovering lithium from geothermal brines, nitrogen and phosphorus from municipal and industrial wastewaters, rare earth elements from mining waste streams, and uranyl ions from seawater.The overall goal of this project is to achieve enhanced selectivities in ISM separations by purposeful control of two opposing driving forces for ion transport, i.e., dual-driving force operation. The specific objectives of the research are: 1) develop a membrane fabrication platform for composite ion-selective membranes in dual-driving force operation, 2) demonstrate the rational control of dual-driving force operation to enhance ISM selectivity for counterions with different mobilities, and 3) engineer the suppression of co-ion leakage using dual-driving force operation to improve ISM permselectivity. Successful execution of the project will enable the ISMs to i) depart from the affinity-mobility constraint on counterion transport and ii) attain improved exclusion of co-ions even at elevated solution ionic strengths. The research will systematically study the underlying factors governing transport and selectivity in ISMs and provide mechanistic insights into membrane design and operation strategies. The project will integrate education and research to train and prepare graduate, undergraduate, and high school students in STEM. The PI will engage in activities including: (i) developing modules for K-12 education and public outreach, (ii) enhancing undergraduate and graduate courses by integrating scientific concepts and technical principles of the research into class syllabus, and (iii) providing undergraduate research opportunities through structured programs.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.

许多重要的能源、水和环境分离过程都需要能够选择性分离水性混合物中不同离子的技术。离子选择性膜 (ISM) 是具有带电离子官能团的聚合物薄膜，允许带相反电荷的物质（抗衡离子）通过膜传输，同时保留带相同电荷的离子（共离子）。施加驱动力（静电势）以将离子传输通过膜。 ISM 已用于燃料电池和电渗析海水淡化等商业应用，但它们表现出的性能限制阻碍了它们在许多工业相关条件下的应用。首先，ISM 在电解质浓度较高时，反离子和共离子之间的选择性会降低。 ISM 也无法区分具有相同化合价的反离子。该项目将研究使用第二个同步驱动力（液压）来改变不同离子的相对渗透。通过协调两个驱动力的大小和方向，称为“双驱动力”操作，可以克服上述ISM选择性的两个缺点。开发更具选择性的离子分离技术可以释放非传统水源水资源回收的机会，包括从地热盐水中回收锂、从城市和工业废水中回收氮和磷、从采矿废水中回收稀土元素以及从海水中回收铀酰离子。该项目的总体目标是通过有目的地控制两个相反的驱动力来提高ISM分离的选择性 用于离子传输，即双驱动力操作。该研究的具体目标是：1）开发用于双驱动力操作的复合离子选择性膜的膜制造平台，2）展示双驱动力操作的合理控制以增强ISM对不同迁移率的反离子的选择性，以及3）利用双驱动力操作设计抑制共离子泄漏以提高ISM选择性渗透性。该项目的成功执行将使 ISM 能够 i) 摆脱抗衡离子传输的亲和迁移率限制，ii) 即使在溶液离子强度升高的情况下，也能改善共离子的排除。该研究将系统地研究控制 ISM 中传输和选择性的潜在因素，并为膜设计和操作策略提供机制见解。该项目将整合教育和研究，为研究生、本科生和高中生提供 STEM 培训和准备。 PI 将参与的活动包括：(i) 开发 K-12 教育和公共宣传模块，(ii) 通过将研究的科学概念和技术原理纳入课程大纲来加强本科生和研究生课程，以及 (iii) 通过结构化项目提供本科生研究机会。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评估进行评估，被认为值得支持。 影响审查标准。