Modulating Polymer Dynamics via Supramolecular Interaction with Ultrasmall Nanocages for Recyclable Gas Separation Membranes with Intrinsic Microporosity

Abstract

The engineering of mixed-matrix membranes is severely hindered by the trade-off between mechanical performance and effective utilization of inorganic fillers' microporosity. Herein, we report a feasible approach for optimal gas separation membranes through the fabrication of coordination nanocages with poly(4-vinylpyridine) (P4VP) via strong supramolecular interactions, enabling the homogeneous dispersion of nanocages in polymer matrixes with long-term structural stability. Meanwhile, suggested from dynamics studies, the strong attraction between P4VP and nanocages slows down polymer dynamics and rigidifies the polymer chains, leading to frustrated packing and lowered densities of the polymer matrix. This effect allows the micropores of nanocages to be accessible to external gas molecules, contributing to the intrinsic microporosity of the nanocomposites and the simultaneous enhancement of permselectivities. The facile strategy for supramolecular synthesis and polymer dynamics attenuation paves avenues to rational design of functional hybrid membranes for gas separation applications.

Supramolecular Polymer Networks of Ion-Coordinated Polybenzimidazole with Simultaneously Improved H2 Permeability and H2/CO2 Selectivity

“…Supramolecular polymer networks (SPNs) comprising polymers coordinated by ions have been widely explored for various applications, such as self-healing, , stimuli-responsive materials, , catalysts, , and liquid separations. , The noncovalent interactions between the ions and polymers can enhance the packing efficiency of the polymer chains, increasing the size-sieving ability and mechanical properties. , Particularly, the ion-coordinated SPNs have been developed for membrane gas separations, , such as polyMOFs, − metal-induced ordered microporous polymers, and ion-coordinated poly­(ethylene oxide). , For example, Cu 2+ or Zn 2+ ions were used to induce the formation of ordered microstructures in amine-containing polymers, rendering superior CO 2 /N 2 separation properties …”

Self‐Healing and Shape Memory Hypercrosslinked Metal‐Organic Polyhedra Polymers via Coordination Post‐Assembly

“…In the low‐q range (0.15 to 0.25 Å −1 ) of SAXS data, the resolved broad peak could be assigned to the structure factor of MOP‐1(M) and indexed as the average distances (d, inversely proportional to the q) between neighboring MOPs in the polymer matrix. With the increase of MOPs amount, the average distances gradually decreased, indicating the increase of crosslinking degree [6c] . Notably, CHMOP‐1(M) membranes with outstanding mechanical properties could be repeatedly bent, twisted, or stretched without damage, and lift a steel object >200 g (Figure 2b, S14 and Video S1–S4).…”

Strategies for the Construction of Functional Materials Utilizing Presynthesized Metal‐Organic Cages (MOCs)

“…In 2021, Yin and co-workers synthesized MMMs by using poly(4-vinylpyridine) (P4VP) and MOC-14. [62] As shown in Figure 15, both coordination and hydrogen-bonding interactions between the MOCs and the P4VP were formed in the MMM 41. Such strong supramolecular association ensures the homogeneous dispersion of MOCs in the P4VP matrix and promotes surface confinement of P4VP by MOCs.…”

“…The interaction of MOCs and polymers can be enhanced by the introduction of polymers with coordination ligands. In 2021, Yin and co‐workers synthesized MMMs by using poly(4‐vinylpyridine) (P4VP) and MOC‐14 [62] . As shown in Figure 15, both coordination and hydrogen‐bonding interactions between the MOCs and the P4VP were formed in the MMM 41 .…”