Mixed‐matrix gas separation membranes for sustainable future: A mini review

Abstract

Mixed‐matrix membranes (MMMs), merging the advantages of polymers and inorganic fillers, has become a preferable choice as future gas separation membrane. Owing to hierarchical structures, MMMs are suitable for high‐performance gas separation capability. Research on extended porous organic/inorganic materials also known as fillers of intrinsic nanopores (FINS) such as porous organic frameworks (POFs), Zeolites, metal–organic frameworks (MOFs), porous organic cages (POCs) and analogous metal–organic polyhedral (MOPs) have bloomed over the last two decades. MOFs and POFs have been proposed as good adsorbent and promising filler components for industrial gas separations, due to their prominent porosity and structural flexibility and also for MMMs with good performance in terms of permeance and selectivity. They are compatible for providing additional molecular transport channels as well as having good size‐sieving property. This review briefly outlines the innovative trends in MMMs, highlighted with different porous fillers as well as suitable polymers followed by their synthesis and their suitable application in gas separations. Finally, a state of art and challenges in the direction of actual application of MMMs in different industries are outlined in terms of inter relation and regarding the future direction and potential growth opportunities of MMMs an elaborate discussion is provided.

Challenges, Opportunities and Future Directions of Membrane Technology for Natural Gas Purification: A Critical Review

“…The development of defect-free MMM is considered challenging as its fabrication suffers from polymer filler incompatibility. Poor interaction between polymer and filler that leads to the formation of non-selective voids can cause pore blockage, polymer rigidification and sieve-in-cage morphology, which deteriorates membrane performance [ 161 ]. Thus, having good polymer-filler compatibility is important.…”

Computational Investigation of Dual Filler-Incorporated Polymer Membranes for Efficient CO2 and H2 Separation: MOF/COF/Polymer Mixed Matrix Membranes

“…Both experimental and computational studies showed that many MOF and COF membranes can exhibit high gas permeabilities. , Synthesis of thin-film membranes from crystalline materials is challenging due to many issues such as poor interactions with the substrates, crack formation, and moisture instability, which affect the practical implementation and scalability of thin-film MOF and COF membranes . Therefore, MOFs and COFs have been recently used as filler particles in polymers to make MMMs . Incorporation of MOFs as fillers into polymers has led to many MOF/polymer MMMs, which offer higher gas permeability and/or selectivity than the pure polymer membrane, but these MMMs generally suffer from compatibility issues between MOFs and polymers due to the inorganic nature of MOFs .…”

“…19 Therefore, MOFs and COFs have been recently used as filler particles in polymers to make MMMs. 20 Incorporation of MOFs as fillers into polymers has led to many MOF/polymer MMMs, which offer higher gas permeability and/or selectivity than the pure polymer membrane, but these MMMs generally suffer from compatibility issues between MOFs and polymers due to the inorganic nature of MOFs. 21 On the other hand, COFs offer better interfacial compatibility with polymers compared to MOFs thanks to the completely organic structure of COFs.…”

Pebax/poly(vinyl alcohol) mixed matrix membrane incorporated by amine‐functionalized graphene oxide for CO2 separation

“…These membranes combine the exceptional separation capabilities of molecular sieve materials with the cost-effectiveness of organic polymer materials. [1][2][3][4][5][6] The inorganic materials employed as the dispersed phase in the construction of MMMs possess distinctive chemical structures and exceptional mechanical strength. Their incorporation into the polymer matrix not only enhances the membrane's mechanical and thermal durability but also augments its separation capabilities.…”