Constructing Connected Paths between UiO‐66 and PIM‐1 to Improve Membrane CO₂ Separation with Crystal‐Like Gas Selectivity

Abstract

Most metal–organic‐framework‐ (MOF‐) based hybrid membranes face the challenge of low gas permeability in CO2 separation. This study presents a new strategy of interweaving UiO‐66 and PIM‐1 to build freeways in UiO‐66‐CN@sPIM‐1 membranes for fast CO2 transport. In this strategy, sPIM‐1 is rigidified via thermal treatment to make polymer voids permanent, and concurrently polymer chains are mutually linked onto UiO‐66‐CN crystals to minimize interfacial defects. The pore chemistry of UiO‐66‐CN is kept intact in hybrid membranes, allowing full utilization of MOF pores and selective adsorption for CO2. Separation results show that UiO‐66‐CN@sPIM‐1 membranes possess exceptionally high CO2 permeability (15433.4–22665 Barrer), approaching to that of UiO‐66‐NH2 crystal (65–75% of crystal‐derived permeability). Additionally, the CO2/N2 permeation selectivity for a representative membrane (23.9–28.6) moves toward that of single crystal (24.6–29.6). The unique structure and superior CO2/N2 separation performance make UiO‐66‐CN@sPIM‐1 membranes promising in practical CO2 separations.

Fabrication of a Hydrogen‐Bonded Organic Framework Membrane through Solution Processing for Pressure‐Regulated Gas Separation

“…However, this type of polycrystalline membranes are usually prepared via hydrothermal or solvothermal methods, which are challenging for scale‐up, compared to the solution processing of polymer. Mixed‐matrix membranes composed of polymers and inorganic microporous fillers are therefore under intensive study today, while the issues of interfacial gaps and inhomogeneous dispersion still needs to be solved . Thus, materials with uniform pore structure that can be easily fabricated into continuously membranes are highly demanded for membrane based gas separation.…”

Adsorbents for Noxious Gas Sequestration: State of the Art

“…Membranes have also shown promising permeance and selectivity for CO 2 in flue gas mixtures. UiO-66CN@sPIM-1 [120] The same applies to their regenerability and reusability except for Polymer PCP-1 [142] which showed very low reusability potential due to the reduced number of pores during successive sorption cycles as a result of structural collapse.…”

“…Progress in this regard has been recorded in literature where properties of membranes have been optimized even though challenges such as high cost, low physical and chemical stability, low selectivity, and low hydrothermal stability persist [118]. This structure optimization has resulted in the synthesis of different classes of membranes [110,[119][120][121][122].…”

Recent Advances of Gas Transport Channels Constructed with Different Dimensional Nanomaterials in Mixed‐Matrix Membranes for CO2 Separation

“…Zhu's group innovated a novel method to interweave PIM-1 and UiO-66 to construct channels in UiO-66-CN@sPIM-1(sPIM-1 referred to the heat-treated PIM-1) membranes to enhance CO 2 transport (Figure 13). [46] Specifically, sPIM-1 with permanent pores was rigidified through thermal treatment, and then polymer chains were grafted onto UiO-66-CN nanoparticles to decrease the occurrence of interfacial defects. The interweaving method (Figure 13a) includes the following features.…”