Interfacially Engineered Membranes for Simultaneous Microwave Catalysis and Liquid Filtration

膜基过滤在工业上广泛用于分离混合物中的不同组分（离子、分子和颗粒）。从废水处理和海水淡化到化学和生物产品制造，膜的应用范围很广。传统膜技术的性能通常会随着时间的推移而下降，因为不需要的物质或溶质会积聚在膜表面和孔内，这一过程被称为“污染”。膜污染最终会阻止所需的流体通过膜，最终需要清洗或更换膜。除了污染问题外，膜技术目前还不足以消除流体中的微量、低分子量有机污染物。本项目将开发一种微波辅助膜过滤工艺，旨在提高过滤性能，增强污染物降解，减轻膜污染。这项研究将支持智能功能膜系统的制造，用于通过微波催化膜过滤进行可持续的水和化学处理或净化。研究活动将为催化和反应膜系统的新教学模块、实验室手册、创新学习经验和专业发展计划的创建提供信息。利用与专业协会和路易斯·斯托克斯少数民族参与联盟的伙伴关系，将招募来自STEM中代表性不足群体的本科生进行暑期研究项目。本项目旨在开发一种微波辅助膜过滤工艺，在膜分离过程中直接引入微波催化。微波有望穿透膜基质，激发微波反应催化剂产生活性自由基，降解污染物，减轻污染。膜的辐照进一步有望引起快速的水蒸发和界面纳米气泡，通过无化学过程最大限度地减少污染。功能化的膜制造工艺将被开发，并将评估膜的稳定性和反应性。对纳米气泡和自由基的形成动力学、污染物降解效率和防污性能的基本理解也将发展为一套候选催化剂和膜材料和类型。该研究还将应用创新技术进行微波辐射下催化剂活性和自由基形成的原位电化学评估以及微波穿透性评估。本研究的预期结果是：(1)优化了具有可调催化剂涂层结构的催化剂涂层陶瓷膜的制备工艺；(2)量化微波辅助过滤系统的防污效能和降解性能；(3)了解微波辅助类芬顿反应和纳米气泡/自由基形成的机理，以及这些过程在污染物降解和抗污染中的作用；(4)开发可调的微波反应膜系统，将催化反应和膜过滤结合起来。该项目的最终愿景是将被动膜过滤过程转变为下一代反应膜，主动降解水污染物并防止表面污染。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。

Membrane-based filtration is widely used by industry for separating distinct components (ions, molecules, and particles) within mixtures. Membranes find use in applications ranging from wastewater treatment and desalination to chemical and biological product manufacturing. The performance of conventional membrane technology generally decreases over time as undesirable substances or solutes accumulate at the membrane's surface and within its pores, which is a process called "fouling." Membrane fouling eventually prevents the desired fluid from passing through the membrane, eventually requiring the membrane to be cleaned or replaced. Separate from the issue of fouling, membrane technology is currently inadequate for eliminating trace-level, low molecular weight organic pollutants from fluids. This project will develop a microwave-assisted membrane filtration process designed to improve filtration performance, enhance pollutant degradation, and mitigate membrane fouling. The research will support manufacturing of smart functional membrane systems for sustainable water and chemical treatment or purification via microwave-catalytic membrane filtration. Research activities will inform the creation of new teaching modules, laboratory manuals, innovative learning experiences, and professional development programs on catalytic and reactive membrane systems. Leveraging partnerships with professional societies and the Louis Stokes Alliance for Minority Participation, undergraduate students from underrepresented groups in STEM will be recruited to conduct summer research projects. This project aims to develop a microwave-assisted membrane filtration process that introduces microwave-initiated catalysis directly within the membrane-based separation process. Microwaves are expected to penetrate the membrane matrix and energize the microwave-responsive catalysts to produce reactive radicals degrade pollutants and mitigate fouling. The irradiation of the membrane is further expected to cause rapid water vaporization and interfacial nanobubbling, minimizing fouling via a chemical-free process. Functionalized membrane fabrication processes will be developed, and the stability and reactivity of the membranes will be assessed. Fundamental understanding of formation kinetics of nanobubbles and radicals, pollutant degradation efficiency, and antifouling performance will also be developed for a suite of candidate catalysts and membrane materials and types. The study will also apply innovative techniques for in situ electrochemical assessment of catalyst activity and radical formation under microwave irradiation and evaluation of microwave penetration. The expected outcomes of this research are: (1) optimized fabrication processes for catalyst-coated ceramic membranes with tunable catalyst coating structures; (2) quantification of antifouling efficacy and degradation performance of the microwave-assisted filtration system; (3) understanding of the mechanisms of microwave-assisted Fenton-like reactions and nanobubbles/radical formation the role these processes play in pollutant degradation and fouling resistance; and (4) development of tunable, microwave-enabled reactive membrane systems that combine catalytic reactions and membrane filtration. The ultimate vision of the project is the transformation of passive membrane filtration processes into next-generation reactive membranes that proactively degrade water contaminants and prevent surface fouling.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.