Accelerating CO₂ capture of highly permeable polymer through incorporating highly selective hollow zeolite imidazolate framework

Abstract

The implementation of high-performance membranes in large-scale CO 2 capture has the potential to significantly decrease the capture cost and reduce the environmental footprints. However, highly permeable polymers rarely have sufficient selectivity for energy-efficient carbon capture. In this study, zeolite imidazolate framework hollow nanoparticles (ZIF-HNPs) were synthesized and embedded into highly permeable polymers as versatile fillers to prepare mixed matrix membranes (MMMs). The interior hollow architecture minimizes transport resistance of gas diffusion through the fillers while its molecular-sieving shell provides high selectivity. With 28 vol% loading of ZIF-HNPs, the membrane exhibits CO 2 permeability of 7,128 Barrer and CO 2 /CH 4 selectivity of 16.4 (57.7% and 31.4% higher than these of pristine membrane), which surpass the upper bound of the state-of-the-art reported polymeric membranes. Meanwhile, we proposed a modified Maxwell model based on the hierarchical structure of the MMM to analyze the effects of cavity size and loading on gas transport behaviors within membranes.

Sorption-enhanced mixed-gas transport in amine functionalized polymers of intrinsic microporosity (PIMs)

“…For the comparison shown in Fig. 5a, only literature studies reporting (1) pure-gas permeability measured at a pressure consistent with the CO 2 partial pressure reported for the mixed gas test, and ( 2 values than backbones containing groups such as -F, -H, or -CN 18,23,35,[92][93][94][95][96][97] . Moreover, all polymers considered from the literature have below 5.5 and a less than 1.5.…”

Mitigation of Physical Aging with Mixed Matrix Membranes Based on Cross-Linked PIM-1 Fillers and PIM-1

“…Introduction of additives such as nanoparticles and microporous organic fillers has also been among the promising approaches for inhibition of aging. Mixed matrix membranes (MMMs) based on PIM-1 and various organic and inorganic fillers have been studied for gas separation. − Inclusion of certain fillers, such as functionalized graphene and graphene oxide (GO), hyper-cross-linked polymer (HCP), − and polyaromatic framework (PAF-1) has shown promising effects toward impeding or even ending aging. It has been shown that the similar composition of nanoporous organic fillers, or more specifically the aryl-H groups of PAF-1 and methyl groups of PIM-1 and PTMSP, result in formation of molecular interactions at the interface and therefore an antiaging effect in the MMMs …”

Large‐area vacuum‐treated ZIF‐8 mixed‐matrix membrane for highly efficient methane/nitrogen separation

“…Membrane technology has extensively shown its merits in gas separation in the last decade 8 . Mixed‐matrix membranes (MMMs) combine the advantages of polymer dense membranes and porous membranes and, as a result, have attracted great attention 9 . As a porous crystalline material with organic linkers and metal ions, MOFs are widely used as fillers because of their ultrahigh specific surface area, high porosity, high affinity for gas molecules, and adjustable pore size 10 …”