Molecularly Precise Gas Separations Through Site-Specific Membrane Design
Abstract
Air revitalization on submarines represents an important challenge for maintaining the health and safety of the crew. Of particularconcern is removal of CO2 from these confined spaces, and there is a need for CO2 removal systems that are efficient, occupy a small footprint, and avoid operational complexities. Membrane-based systems can provide all of these benefits, but state-of-the-art membrane materials lack permeability and selectivity necessary to separate CO2 from other atmospheric gases of similar sizes. Instead ofusing size sieving as the primary mechanism of separation, this proposal aims to develop microporous membrane materials that have outstanding selectivities for CO2 over other gases by leveraging competitive sorption. This effect enables dissolution of CO2 into the membrane material, which subsequently excludes other gas molecules with lower affinity for the membrane pore structure, enhancing selectivity. Two classes of materials will be developed to enable competitive sorption in membranes, including polymers of intrinsic microporosity (PIMs) and metalorganic frameworks (MOFs). Site-specific features, such as CO2-philic functional groups, unsaturated metal sites, and facilitated transport carriers will be used to selectively interact with CO2. Through this proposal, the theory and experimental validation of these effects will be evaluated to provide guiding principles that enable the use of membranes for various separations, including CO2 removal from the submarine environment.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 05, 2021
- Source ID
- N000142112666
Entities
People
- Zachary P Smith
Organizations
- Massachusetts Institute of Technology
- Office of Naval Research
- United States Navy