Aminopolymers, poly(ethylene imine) (PEI) and poly(propylene imine) (PPI), are supported within nanoporous UiO-67(Zr) and evaluated for CO2 capture from simulated flue gas (10% CO2) and air (400 ppm CO2). N2 physisorption and Fourier-transform infrared spectroscopy indicate that PEI and PPI are physisorbed in UiO-67(Zr) voids but not tethered to metal nodes or carboxylate backbones. Mass-normalized CO2 capacity increases with repeated CO2 uptake-regeneration cycles for 30-50 wt% PPI, suggesting CO2 diffusion limitations at these higher loadings. 20 wt% PPI/UiO-67(Zr) and 20 wt% PEI/UiO-67(Zr) exposed to ambient air for 7 days demonstrate higher oxidative degradation in PEI than PPI, though PEI oxidation is reduced when stabilized within UiO-67(Zr) relative to when unconfined. Exposure of composites to liquid storage environments of varying polarity, hydrogen-bonding capability, and size indicate that 20 wt% PPI/UiO-67(Zr) amine efficiencies are minimally affected by solvent-induced aminopolymer conformational changes. Conversely, 20 wt% PEI/UiO-67(Zr) is more sensitive to surrounding solvent environments, exhibiting the greatest amine efficiency in methanol and the lowest in acetone due to solvent-induced aminopolymer swelling and reaction, respectively. Overall, this work provides insight into CO2 capture efficacies and chemical stabilities of composite PEI and PPI materials under various storage environments to inform future adsorbent and system design.
|Original language||English (US)|
|Number of pages||9|
|State||Published - Jan 10 2023|
All Science Journal Classification (ASJC) codes
- Chemistry (miscellaneous)
- Materials Science(all)