DMREF: GOALI: Salt Separation Membranes Based on Modifiable Two-Dimensional Covalent Organic Frameworks

University Of Wyoming, Laramie WY

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). NON-TECHNICAL SUMMARY The global disruptions to standard operations that are occurring due to changing climate conditions, changing rainfall patterns, and increased human population will continue to stress the world’s freshwater supplies. This is predicted to result in half of the population facing freshwater shortages by 2030. Because only about 3% of all water on Earth is suitable for human consumption and the oceans contain 97% of the Earth’s water, energy-efficient desalinization (salt separation) technologies are crucial for maintaining society’s quality of life. Reverse osmosis (RO) is currently the most employed and reliable method for water desalinization; however, improvements in process efficiency are needed to make it a more sustainable treatment option. These improvements center on the physical and chemical characteristics of the membrane materials and membrane modules to address issues related to salt selectivity, water permeability, and chemical tolerance. This project will produce new generations of membrane materials that could possibly be more stable, selective, and energy-efficient than current RO membranes. Moreover, these materials and systems have the potential to be modified for other water purification applications such as the removal of specific contaminants. TECHNICAL SUMMARY The new membrane materials will be based on two-dimensional covalent organic frameworks (2D-COFs), 2D polymers with a defined but modifiable pore structure, which can be synthesized with a high degree of order. Furthermore, the effort will develop synthetic strategies for putting a wide variety of functional groups in the pores. The 2D flake-like nature of the materials make them naturally suited for semipermeable membrane applications. The focus of the project will be on placing charged functional groups in the pores and changing the pore sizes to make ion-selective membranes that reject either anions or cations with a specific size threshold. The interdisciplinary team associated with this project consists of a synthetic organic chemist, an electrochemist/materials scientist, a membrane engineering specialist, and a computational scientist. Thus, the project will use a feedback loop between the organic synthesis of the membrane, membrane performance testing, and computational modeling and machine learning to guide the syntheses of the new membrane materials and optimize their performance for a particular separation. When this is combined with the input and actions of the industrial partner on the effort, this project will take a Materials Genome Initiative (MGI) approach to research such that materials discovery and deployment is accelerated. 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.