skip to main content


Search for: All records

Creators/Authors contains: "Cho, Stanley"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Abstract

    Rising anthropogenic carbon emissions have dire environmental consequences, necessitating remediative approaches, which includes use of solid sorbents. Here, aminopolymers (poly(ethylene imine) (PEI) and poly(propylene imine) (PPI)) are supported within solid mesoporous MIL‐101(Cr) to examine effects of support defect density on aminopolymer‐MOF interactions for CO2uptake and stability during uptake‐regeneration cycles. Using simulated flue gas (10 % CO2in He), MIL‐101(Cr)‐ρhigh(higher defect density) shows 33 % higher uptake capacity per gram adsorbent than MIL‐101(Cr)‐ρlow(lower defect density) at 308 K, consistent with increased availability of undercoordinated Cr adsorption sites at missing linker defects. Increasing aminopolymer weight loadings (10–50 wt.%) within MIL‐101(Cr)‐ρlowand MIL‐101(Cr)‐ρhighincreases amine efficiencies and CO2uptake capacities relative to bare MOFs, though both incur CO2diffusion limitations through confined, viscous polymer phases at higher (40–50 wt.%) loadings. Benchmarked against SBA‐15, lower polymer packing densities (PPI>PEI), weaker and less abundant van der Waals interactions between aminopolymers and pore walls, and open framework topology increase amine efficiencies. Interactions between amines and Cr defect sites incur amine efficiency losses but grant higher thermal and oxidative stability during uptake‐regeneration cycling. Finally, >25 % higher CO2uptake capacities are achieved for aminopolymer/MIL‐101(Cr)‐ρhighunder humid conditions, demonstrating promise for realistic applications.

     
    more » « less