Abstract
Efficient carbon capture from stationary point sources can be achieved using hybrid adsorbents comprising nanoporous substrates coated with imine polymers. The physical properties of the CO2-adsorbing, nanodispersed polymers are altered by their interactions with the substrate, which in turn may impact their capture capacity. We study silica and carbon nanoporous substrates with different pore morphologies that were impregnated with polymer imine with the goal of characterizing the polymer dispersions in the pores. For silica and carbon samples, the mean densities of confined poly(ethylene imine) (PEI) were measured as functions of polymer loading and temperature using small-angle neutron scattering. Strong densification is found for imine polymers imbibed in mesoporous carbon. PEI in nanoporous silica does not experience this strong densification. At high loadings, plugs form, preferably at the pore throats, and can reduce accessible porosity. CO2 capture measurements show that PEI interactions with the substrate play an important role. PEI in carbon shows the highest capture capacity at low temperatures and the lowest CO2 adsorption at high temperatures, making it well-suited for temperature swing adsorption applications.
| Original language | English |
|---|---|
| Pages (from-to) | 4622-4631 |
| Number of pages | 10 |
| Journal | Langmuir |
| Volume | 37 |
| Issue number | 15 |
| DOIs | |
| State | Published - Apr 20 2021 |
Funding
We thank Christopher W. Jones and Matthew E. Potter at Georgia Tech University for providing the deuterated polymers, impregnation of the supports, CO capture measurements, TGA and liquid N measurements, and stimulating discussions. This research was supported as part of UNCAGE-ME, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under award # DE-SC0012577, and the Center for Nanophase Materials Sciences, which are US Department of Energy Office of Science User Facilities. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. This manuscript was authored by UT-Battelle, LLC under contract no. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). 2 2