(680a) PIM-1/Poly(ethylene imine) Composites As Solution-Processable “Molecular Baskets” for CO2 Capture from Dilute Streams

Research for CO₂ capture from dilute streams such as flue gas or ambient air has received increased attention within the last several decades due to rising atmospheric CO₂ levels. Recently, much research has focused on the use of solid sorbent materials composed of mesoporous oxides with tethered or impregnated polymeric amine materials. However, these materials are difficult to process and implement at the scales required for real CO₂ capture applications due to difficulties associated with heat and mass transport and high pressure drops through the powder materials.

Polymers of intrinsic microporosity (PIMs) are highly porous, solution-processable materials that theoretically could act as supports for amines such as poly(ethylene imine) (PEI) for CO₂ capture. These materials can be shaped into a variety of morphologies such as monoliths, hollow fibers and thin film membranes, which can have beneficial implications for heat and mass transfer properties of the final material.

In this contribution, we demonstrate the use of a PIM-1/PEI composite system for dilute CO₂ capture. We demonstrate that these composites, in powder, monolith, and dense film form, exhibit comparable performance to their inorganic powder counterparts, exhibiting good CO₂ capacity, uptake kinetics, and stability under simulated flue gas and air capture conditions and rapid temperature swing operation. Spin-diffusion solid-state NMR experiments were performed to demonstrate that PEI is well-dispersed within the PIM-1 pores at all loadings, allowing for rapid CO₂ uptake kinetics. Our results suggest that other solution-processable, intrinsically porous polymers may be applicable as supports for amine sorbents.