Interfacially Engineered Membranes for Simultaneous Microwave Catalysis and Liquid Filtration

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.