Defect‐Free Mixed‐Matrix Membranes with Hydrophilic Metal‐Organic Polyhedra for Efficient Carbon Dioxide Separation

Abstract

Defect-free mixed-matrix membranes (MMMs) were prepared by incorporating hydrophilic metal-organic polyhedra (MOPs) into cross-linked polyethylene oxide (XLPEO) for efficient CO separation. Hydrophilic MOPs with triethylene glycol pendant groups, which were assembled by 5-tri(ethylene glycol) monomethyl ether isophthalic acid and Cu ions, were uniformly dispersed in XLPEO without particle agglomeration. Compared to conventional neat XLPEO, the homogenous dispersion of EG -MOPs in XLPEO enhanced CO permeability of MMMs. Upon increasing the amount of EG -MOPs, the membrane performance such as CO /N selectivity was steadily improved because of unsaturated Cu sites at paddle-wheel units, which was confirmed by Cu K-edge XANES and TPD analysis. Therefore, such defect-free MMMs with unsaturated metal sites would contribute to enhance CO separation performance.

Self-Healing Hyper-Cross-Linked Metal–Organic Polyhedra (HCMOPs) Membranes with Antimicrobial Activity and Highly Selective Separation Properties

“…This in turn enables facile postsynthetic modification of MOPs to promote interactions with other materials such as polymers. − However, until now, only few approach (i.e., MMMs or photopolymerization) have been used to incorporate MOPs into polymers in order to fabricate hybrid membranes (Figure S1 of the Supporting Information, SI). − Unfortunately, these hybrid membranes may still suffer from leaching of MOPs, poor mechanical properties and limited functionality. Herein, we address these issues by introducing a new concept: hyper-cross-linked MOPs (HCMOPs).…”

Modeling Permeation through Mixed-Matrix Membranes: A Review

“…Furthermore, we compare predictions of popular permeation models against available experimental and simulation-based permeation data, and discuss the suitability of these models for predicting MMM permeability under typical operating conditions. Thus, much effort has been devoted to the optimization of MMMs synthesis [34,42,[45][46][47][48]; with a number of works even reporting fabrication of defect-free MMMs [37,[49][50][51].Ideally, a mixed-matrix membrane (MMM) consists of a selective inorganic filler phase embedded to continuous polymer matrix [21,35]. In this way, an MMM combines high intrinsic permeability and separation efficiency of advanced molecular sieving materials (e.g., zeolites, carbons, metal-organic frameworks) or nanoscale materials (e.g., carbon nanosheets or nanotubes) with robust processing capabilities and mechanical properties of glassy polymers [23,52].…”

“…Furthermore, we compare predictions of popular permeation models against available experimental and simulation-based permeation data, and discuss the suitability of these models for predicting MMM permeability under typical operating conditions. Thus, much effort has been devoted to the optimization of MMMs synthesis [34,42,[45][46][47][48]; with a number of works even reporting fabrication of defect-free MMMs [37,[49][50][51].…”

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

“…CNCs with 24 surface phenol groups are applied to hybridization with P4VP via both hydrogen-bonding and coordination interactions to construct robust MMMs. Due to their synthetic feasibility, only CNCs constructed from isophthalic acid (IPA) and Cu 2+ have been used for the fabrication of MMMs. − Nevertheless, the labile nature of the Cu­(II)–carboxylate coordination bond leads to the easy decomposition of CNCs and long-term instabilities of MMMs . Therefore, CNCs from the coordination of IPA and Rh­(II) centers are applied here as an inorganic filler for their robust structures, ultrasmall sizes, and capability to coordinate with P4VP via vacant sites of Rh centers (Figure a).…”