Synthesis of Ultrathin Zeolitic Imidazolate Framework ZIF-8 Membranes on Polymer Hollow Fibers Using a Polymer Modification Strategy for Propylene/Propane Separation

Abdul Hamid, Mohamad Rezi,Park, Sunghwan,Kim, Ju Sung,Lee, Young Moo,Jeong, Hae-Kwon American Chemical Society 2019 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.58 No.32

<P>Polycrystalline zeolitic imidazolate framework ZIF-8 membranes have shown great potential for energy-efficient propylene/propane separation. Their large-scale applications are, however, hampered by the lack of facile and cost-effective processing technologies for ultrathin ZIF-8 membranes on scalable substrates. Here, we report facile preparation of ultrathin ZIF-8 membranes on the bore side of Matrimid hollow fibers based on a polymer modification strategy. Site-selective nature of the method enables a positional control over locations (i.e., bore or shell side) of active ZIF-8 layers on the hollow fibers. The ZIF-8 membranes grown on the bore side of Matrimid hollow fibers with polydimethylsiloxane coating displayed an average propylene permeance and a separation factor of ∼152 × 10<SUP>-10</SUP> mol·m<SUP>-2</SUP>·Pa<SUP>-1</SUP>·s<SUP>-1</SUP> and ∼55, respectively. Optimization of ZIF-8 seeding step resulted in an improvement in propylene permeance (∼369 × 10<SUP>-10</SUP> mol·m<SUP>-2</SUP>·Pa<SUP>-1</SUP>·s<SUP>-1</SUP>) while maintaining relatively high separation factor (∼40).</P> [FIG OMISSION]</BR>

Zeolitic imidazolate framework membranes for gas separations: Current state-of-the-art, challenges, and opportunities

Mohamad Rezi Abdul Hamid,Thomas Choong Shean Yaw,Mohd Zahirasri Mohd Tohir,Wan Azlina Wan Abdul Karim Ghani,Putu Doddy Sutrisna,Hae-Kwon Jeong 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

Advanced porous materials with uniform molecular scale apertures are highly desirable for energyrelated separations. Among them, zeolitic imidazolate frameworks (ZIFs) have received significantinterest as separation membranes owing to their narrow apertures that can target small gases. ZIFsexhibit excellent gas transport properties, such as unprecedentedly high C3H6 permeability andremarkable C3H6/C3H8 selectivity, inaccessible by other porous inorganic materials and polymers. Deposition of ultrathin ZIFs on porous substrates to form gas-selective barriers has been a major focus inthis area. There has been a significant development in the synthesis of ultrathin ZIF membranes for gasseparations. In this review, we present a summary of current state-of-the-art in ZIF membrane processingand highlight unique microstructural features of the prepared membranes. Following this, we discusslevel of separation performances of these advanced membranes focusing on three emerging/unsolvedapplications. Finally, we provide our perspectives on future research directions in the area.

Flow synthesis of polycrystalline ZIF-8 membranes on polyvinylidene fluoride hollow fibers for recovery of hydrogen and propylene

Mohamad Rezi Abdul Hamid,Hae-Kwon Jeong 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.88 No.-

It is highly desirable to prepare defect-free ZIF-8 membranes on commercially attractive scalable polymer hollow fibers, especially on the bore side of the fibers, yet quite challenging. Herein, we report a facile synthesis of well-intergrown ZIF-8 membranes on polyvinylidene fluoride (PVDF) microfiltration hollow fibers by a secondary growth method. Surface modification using a strong base promoted high heterogeneous nucleation, resulting in densely packed ZIF-8 seed layers on the hollow fibers. The seed crystals were secondarily grown under a continuous flow of growth solution to form ZIF-8 membranes with thickness of ˜1.2 μm. The prepared ZIF-8 membranes achieved high gas permeances, reaching values of 16,344 × 10−10 mol m-2 s-1 Pa-1 for H2 and 197 × 10−10 mol m-2 s-1 Pa-1 for C3H6. The selectivities for H2/CH4, H2/C3H6, H2/C3H8 and C3H6/C3H8 gas pairs were found to be 12, 57, 160 and 15, respectively. We anticipate that the method could potentially be applied to transform commercial PVDF ultrafiltration/microfiltration hollow fibers commonly used for water separation into high quality ZIF-8 membranes for H2 purification and C3H6/C3H8 separation.

Recent advances on mixed-matrix membranes for gas separations: Opportunities and engineering challenges

Mohamad Rezi Abdul Hamid,Hae-Kwon Jeong 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.8

In the past decades, gas separation using polymeric membranes has received considerable attention and become one of the fastest growing research areas. However, existing polymeric membranes may not be able to keep up with the increasing separation needs for challenging gas mixtures such as N2/CH4 and light olefin/paraffin pairs on industrial scale due to their so-called permeability-selectivity bound. On the other hand, scaling-up issues poise huge challenges for highly permeable and highly selective inorganic membranes. Mixed-matrix membranes, composite membranes, provide an evolutionary solution to debottleneck the permeability-selectivity and scale-up issues currently faced by polymeric and inorganic membranes, respectively. Inorganic fillers in mixed-matrix membranes improve gas permeability and/or selectivity, outperforming polymeric membranes. Combined with relatively economical and simple scaling-up compared to inorganic membranes, mixed-matrix membranes could potentially be a next-generation membrane concept for gas separation applications. This review provides a brief summary on the recent progress in both flat sheet and hollow fiber mixed-matrix membranes with an emphasis on those made over the last five years. A separate section is dedicated to discussing engineering challenges transitioning from laboratory-scale to large-scale synthesis of mixed-matrix membranes. Finally, future prospects and perspectives in mixed-matrix membranes research are briefly outlined.

Ultrathin zeolitic-imidazolate framework ZIF-8 membranes on polymeric hollow fibers for propylene/propane separation

Lee, Moon Joo,Abdul Hamid, Mohamad Rezi,Lee, Jongmyeong,Kim, Ju Sung,Lee, Young Moo,Jeong, Hae-Kwon Elsevier 2018 Journal of membrane science Vol.559 No.-

<P><B>Abstract</B></P> <P>Polymer hollow fibers have great potential as cost-effective scalable substrates for the practical applications of highly propylene-selective ZIF-8 membranes. We report ultrathin ZIF-8 membranes supported on porous Matrimid® polymer hollow fibers via microwave-assisted seeding and microfluidic secondary growth. Densely-packed ZIF-8 seed layers were rapidly prepared on polymeric hollow fibers under microwave heating. The seed layers were then secondarily grown into well-intergrown ZIF-8 membranes under the continuous flow of the growth solution. The effects of synthesis parameters on the microstructures of ZIF-8 seed crystals were systematically studied. The resulting ZIF-8 membranes were characterized with XRD and SEM, showing well-intergrown ZIF-8 films formed on the bore of hollow fibers. The unique nature of the current technique enables facile formation of ultrathin ZIF-8 membranes on either the bore or shell side of hollow fibers with a thickness of ~ 800 nm. Propylene/propane binary gas permeation measurements showed an average separation factor of ~ 46 and propylene permeance of ~ 55 GPU.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous Matrimid® hollow fibers were used as ZIF-8 membrane substrates. </LI> <LI> High-quality ZIF-8 seed layers were rapidly formed under microwave. </LI> <LI> Ultrathin ZIF-8 membranes were formed under microfluidic secondary growth. </LI> <LI> Propylene/propane separation performance was measured. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Unlocking the potential of metal-organic frameworks-based mixed matrix membranes for hydrogen separation and purification

Nor Naimah Rosyadah Ahmad,Yang Lee,Mohamad Rezi Abdul Hamid,Tinia Idaty Mohd Ghazi,Rizwan Nasir,Choe Peng Leo,Siaw Paw Koh,Jagadeesh Pasupuleti,Sieh Kiong Tiong 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Membrane-based separation is a promising technology for hydrogen separation and purification due toits low energy consumption. Conventional membranes, such as polymeric membranes, often suffer frompermeability-selectivity trade-offs weakening their potential for challenging gas separations. Metalorganicframeworks (MOFs) with uniform apertures, high porosities, large internal surface areas, and tunablefunctionalities make them excellent fillers in mixed matrix membranes (MMMs) fabrication forhydrogen separation. This review evaluates current state-of-the-art MMMs performances, explores thechallenges in MMMs fabrication, and discusses current strategies in MOF-based MMMs fabrication andmodification aspects to enhance the membrane performance, specifically for H2/CO2, H2/CH4, and H2/N2 separation. Moreover, the hydrogen separation performance of MOF-based MMMs at elevated temperaturesand pressure and improvement in antiaging and antiplasticization properties are discussed indetail. The outlook and perspectives for MOF-based MMMs for hydrogen separation are also provided. This review offers insight into the potential of MOFs as porous fillers in MMMs fabrication for hydrogenseparation application.