NSF-DFG MISSION: Deciphering the carbon dioxide transport in supported thin polyamine films for carbon capture

Technologies that can selectively remove carbon-based molecules such as carbon dioxide (CO2) from the air are needed to stabilize atmospheric CO2 levels and mitigate the impacts of greenhouse gas emissions. These “carbon capture” technologies will significantly impact the global carbon economy, climates, and ecosystems and the sustainability of future manufacturing processes. Sorbent-based technologies are ideal for carbon capture due to their high CO2 selectivity and low energy costs for sorbent regeneration. One such example is mesoporous substrate-supported polyamine systems (MSPAs), where CO2-sorbing polymer films (i.e., polyamines) sit on top of a solid porous material for support (i.e., the mesoporous substrate). However, existing MSPAs have low amine efficiency and slow CO2 sorption and release rates. The reasons for these limitations are poorly understood because it is challenging to characterize CO2 diffusion within MSPAs. Accordingly, researchers at Michigan State University and Leipzig University will collaboratively develop a robust testing platform for in-situ monitoring of CO2 diffusion and carbon capture performance in MSPA-relevant structures. The team’s findings will guide the design of better polyamine-based sorbent systems, reducing the cost of sorbent-based CO2 capture technologies. The international collaboration will provide graduate students valuable interdisciplinary training and engage students from underrepresented groups in STEM. Additionally, the team will develop a graduate-level educational module on CO2 transport in polyamines. Outreach activities will include an international virtual workshop to share research results, inspire discussions and collaborations, and offer career development advice for early-stage investigators. This project aims to develop a new testing platform for in-situ monitoring of CO2 diffusion and capture performance in MSPA-relevant geometries. The CO2 sorption-induced chemical and interfacial effects on CO2 transport will also be investigated. Using a combination of experiments and modeling, the team will develop a nano-broadband dielectric spectroscopy (nano-BDS) testing platform. This nano-BDS platform will help resolve the spatial gradient of CO2 diffusivity, the polyamine dynamics, and how they evolve during CO2 capture. Systematic experiments will be conducted to identify the roles of key design parameters, such as amine types, amine concentrations, film thicknesses, and polyamine-substrate interactions, knowledge of which can be used to optimize MSPAs. The results will help test existing theories and models of gas transport in polymers and develop a new theoretical description of CO2 transport in polyamines. Further, these findings will provide a solid foundation for understanding the temporal changes in thin polyamine films during carbon capture and advance fundamental carbon capture science. 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.