Fabrication Of Mixed Matrix Membranes Research Articles

β-cyclodextrin modified GO ultrafiltration membranes with enhanced antifouling property for water purification

The study investigated the influence of additives on the fabrication of mixed matrix membranes comprising polyethersulfone (PES), with a specific focus on hydrophilicity, flux, morphology, and antifouling properties. Carboxymethyl modified β-cyclodextrin (CMβ-CD) was used to enhance the dispersion and hydrophilicity of graphene oxide (GO), leading to the formation of a hydrophilic and stable composite nanoparticle (CMCD@GO). The hydrophilicity (WCA <51.5°) and water flux (32.6 L.m-2.h-1) of the modified PES membranes (MCDGO-x) were improved by the incorporation of CMCD@GO nanoparticles, while that of PES membrane was 79.7° and 10.6 L.m-2.h-1. The rate of backscattered light intensity (ΔBS) of MCDGO-x suspensions remains stable, suggesting stable dispersion of CMCD@GO in organic solvents. Compared to the bare PES membrane, the MCDGO-x membrane exhibits a thinner active layer and a finger-like structure. The MCDGO-x membrane exhibited excellent naphthenic acids (NAs) rejection (> 93.2%) due to reduced roughness and higher hydrophilicity, while the GO-modified PES membrane (MGO-5) exhibited lower NAs rejection (87.2%). Furthermore, the MCDGO-5 membrane showed higher flux recovery ratio (FRR) of 79.3% compared to MGO-5 membrane (68.5%) after three cycles, indicating the antifouling performance of MCDGO-x for NAs was significantly improved. The combination of CMβ-CD and GO enhance the flux and antifouling properties of PES ultrafiltration membranes, suggesting significant potential for applications in the purification of oil sands process water and the treatment of oily wastewater.

Engineering interfacial interactions for hydrogen separation enhancement in Torlon®/mixed-linker ZIF-8 mixed matrix membranes

Polymer membranes traditionally used for gas separation can be easily fabricated via a solution process; however, they have limitations in gas separation performance. Mixed matrix membrane (MMM) with dispersed high-performance filler within a polymer matrix achieves both excellent separation efficiency and productivity. In this study, we employed Torlon® (polyamide-imide), a chemically stable and commercially available polymer, as the matrix of the membranes. To enhance the separation performance through the fabrication of MMM, we utilized 2abIm-mixed-linker ZIF-8 (ML-ZIF-8) as the filler particles to improve the interfacial interaction with the Torlon® matrix. FT-IR and XPS analyses on the Torlon®/ML-ZIF-8 MMM confirmed the occurrence of interactions between the Torlon® and ML-ZIF-8. As a result, the analysis of both the DSC and stress-strain curves confirmed the effectiveness of incorporating ML-ZIF-8 into the Torlon® for improving the stability of the polymer-filler interface. This enhancement resulted in an approximately 2.7 times higher H2 permeability for the Torlon®/ML-ZIF-8 MMM compared to the pure Torlon® membrane. Furthermore, the selectivity of H2/N2 and H2/CH4 separation increased by around 11 times and 9.6 times, respectively, leading to a significant overall improvement in separation performance.

Orientation of two-dimensional materials mf-BN in Pebax mixed matrix membranes by magnetic fields for enhancing CO2/N2 separation performance

Two-dimensional materials possess a high aspect ratio and excellent spatial utilization, making them potential filler for the fabrication of mixed matrix membranes (MMMs). However, the disordered arrangement of two-dimensional materials can negatively impact membrane performance. In this study, hexagonal boron nitride (h-BN) two-dimensional material loaded with polyethyleneimine (PEI) and magnetic material Fe3O4 was prepared. The filler (mf-BN) was incorporated into Pebax-1657, and the orientation of mf-BN in the MMM was controlled using a magnetic field. Horizontally and vertically oriented mf-BN/Pebax MMMs were successfully prepared and subjected to gas separation tests. The results demonstrate that oriented MMMs exhibit superior performance compared to non-oriented ones. When the mf-BN loading is 20 wt%, the CO2/N2 selectivity for horizontally and vertically oriented MMMs respectively reaches 83.9 and 76.8. The CO2 permeability increases to 114.7 and 139.8 Barrer, respectively. The magnetic field orientation of filler presents a promising approach for further enhancing the performance of MMMs.

Unexpectedly High Propylene/Propane Separation Performance of Asymmetric Mixed-Matrix Membranes through Additive-Assisted In Situ ZIF-8 Filler Formation: Experimental and Computational Studies.

Zeolitic-imidazolate framework-8 (ZIF-8), composed of a zinc center tetrahedrally coordinated with 2-methylimidazolate linkers, has garnered extensive attention as a selective filler for propylene-selective mixed-matrix membranes (MMMs). Recently, we reported an innovative and scalable MMM fabrication approach, termed "phase-inversion in sync with in situ MOF formation" (PIMOF), aimed at addressing the prevailing challenges in MMM processing. In this study, we intend to investigate the effect of additives, specifically sodium formate and 1,4-butanediol, on the modification of ZIF-8 filler formation within the polymer matrix in order to further improve the separation performance of the asymmetric MMMs prepared by the PIMOF. Remarkably, MMMs prepared with sodium formate as an additive in the coagulation bath exhibited an unprecedented C3H6/C3H8 separation factor of 222.5 ± 1.8 with a C3H6 permeance of 10.1 ± 0.3 GPU, surpassing that of MMMs prepared without additives (a C3 separation factor of 57.7 ± 11.2 with a C3 permeance of 22.5 ± 4.5 GPU). Our computational work complements the experimental investigation by studying the effect of ZIF-8 nanoparticle size on the specific surface interaction energy and apertures of ZIF-8. Calculations indicate that by having smaller ZIF-8 nanoparticles, stronger interactions are present with the polymer affecting the aperture of ZIF-8 nanoparticles. This reduction in aperture size is expected to improve selectivity toward propylene by reducing the permeability of propylene. These results represent a significant advancement, surpassing the performance of all previously reported propylene-selective MMMs and most high-quality polycrystalline ZIF-8 membranes. The notably enhanced separation performance primarily arises from the formation of exceedingly small ZIF-8-like particles with an amorphous or poorly crystalline structure, corroborated by our computational work.

Recent advances in the interfacial engineering of MOF-based mixed matrix membranes for gas separation.

The membrane process stands as a promising and transformative technology for efficient gas separation due to its high energy efficiency, operational simplicity, low environmental impact, and easy up-and-down scaling. Metal-organic framework (MOF)-polymer mixed matrix membranes (MMMs) combine MOFs' superior gas-separation performance with polymers' processing versatility, offering the opportunity to address the limitations of pure polymer or inorganic membranes for large-scale integration. However, the incompatibility between the rigid MOFs and flexible polymer chains poses a challenge in MOF MMM fabrication, which can cause issues such as MOF agglomeration, sedimentation, and interfacial defects, substantially weakening membrane separation efficiency and mechanical properties, particularly gas separation. This review focuses on engineering MMMs' interfaces, detailing recent strategies for reducing interfacial defects, improving MOF dispersion, and enhancing MOF loading. Advanced characterisation techniques for understanding membrane properties, specifically the MOF-polymer interface, are outlined. Lastly, it explores the remaining challenges in MMM research and outlines potential future research directions.

Synergistic tuning mixed matrix membranes by Ag+-doping in UiO-66-NH2/polymers of intrinsic microporosity for remarkable CO2/N2 separation

Novel mixed matrix membranes (MMMs) with superior CO2/N2 separation properties are of great importance for post-combustion CO2 capture from flue gas. Metal-organic frameworks (MOFs) as one of the most attractive porous fillers for MMMs fabrication, are considered to provide a solid molecular sieving mechanism for enhancing CO2/N2 selectivity. However, it causes the reduction in gas permeability and limits its further industrialization. Herein, we proposed a new strategy for filler functionalization by doping silver ions (Ag+) into UiO-66-NH2 nanoparticles through the double-solvent method and used for the preparation of advanced MMMs. The double-solvent method is benefits for the enrichment of Ag+ in the hydrophilic pores of UiO-66-NH2. As a result, the prepared novel MMMs called Ag+@UiO@PIM-1 with the polymers of intrinsic microporosity (PIMs) as polymer matrix, show outstanding CO2 permeability. According to the mixed gases (CO2/N2 = 10:90) permeation experiments under 25 °C and 2 bar, the membrane with 30%Ag+@10%UiO loading achieves more than 65% increase in CO2/N2 selectivity (∼30) and 120% in CO2 permeability (>15,000 Barrer) compared to the pristine PIM-1 membrane. By optimizing the Ag+ doping amount and Ag+@UiO loading content, the separation performance exceeds the 2019 CO2/N2 upper bound. To figure out the separation mechanism, the pore texture properties and CO2 affinity of the functional filler (Ag+@UiO) together with the membrane structure were characterized by XPS, PXRD, SEM, gas sorption, etc. The synergistic mechanisms by combing CO2 facilitated transport and molecular sieving from pore regulation were identified to enable advanced CO2/N2 membrane separation.

Mixed matrix membrane for enhanced Ethanol/Water pervaporation separation by incorporation of hydrophilic Zr-MOF NU-906 in chitosan

Conquering the trade-off between selectivity and permeability is crucial for efficient ethanol dehydration. The sophisticated metal–organic frameworks (MOFs) have proven their potential as membrane fillers despite of the limited research on few frameworks. Herein, in order to achieve enhanced water permselectivity, hydrophilic zirconium-based NU-906 nanoparticles were incorporated into chitosan (CS) to fabricate NU-906/CS mixed matrix membranes (MMMs) for alcohol dehydration. The introduction of NU-906 brought excellent water affinity and structural stability to the hybrid membranes confirmed by the water contact angle and swelling resistance tests. Benefiting from the hydrophilicity and the ordered porosity of the incorporated NU-906, simultaneously enhanced water selectivity and permeability have been achieved on the hybrid membranes. The optimum membrane with 5.0 wt% NU-906 exhibited a high flux of 1086 g/(m2·h) and an excellent separation factor of 2651 for 90 wt% ethanol dehydration at 76℃. This research has expanded the range of MOFs available for the fabrication of MMMs and provided new options for organic solvent pervaporation dehydration.

C-axis oriented ZIF-95 sheets intermixed with polyimide matrix with enhanced gas separation performance

The fabrication of mixed matrix membranes (MMMs) by intermixing suitable fillers with organic polymers is an effective strategy to surmount the well-known trade-off effect between gas permeability and selectivity, which can promote separation performance of membranes to a great extent. Two-dimensional (2D) metal-organic frameworks (MOFs) are considered as potential fillers for strengthening the separation performance of MMMs as they possess high aspect ratio and distinctive chemical characteristics. However, it remains challenging in engineering the morphology of the MOFs with desired pore structure and high aspect ratio. In this study, we firstly prepare c-axis oriented ZIF-95 sheets with lateral dimension exceeding 22 μm and thickness of around 3 μm by the solvothermal method. And then the ZIF-95 sheets are incorporated into the polyimide (PI) matrix to fabricate highly c-axis oriented ZIF-95@PI MMMs (denoted as COZIF-95@PI MMMs thereafter). Attributing to the straight permeation channel of ZIF-95 (3.6 Å) for gas permeation as well as its high compatibility with polyimide substrates, the COZIF-95@PI MMMs show a high gas separation capability. At 373 K and 100 kPa for the COZIF-95@PI MMM with 40 wt% loading, the mixture separation factors of H2/CH4 and H2/CO2 are 134 and 58, respectively, and the H2 permeability exceeds 967 barrer, which is hopeful for the separation and purification of hydrogen.

Enhanced adsorptive removal of As(V) ions in aqueous solution using polyethersulfone ultrafiltration mixed matrix membranes impregnated with 3‐aminopropyltriethoxysilane modified magnetite Fe3O4 nanoparticles

AbstractThis study involves the fabrication of mixed matrix membranes (MMMs) for ultrafiltration, which contained 3‐aminopropyltriethoxysilane modified magnetite iron oxide nanoparticles (A‐Fe3O4 NPs), through a modified phase inversion technique. The physiochemical properties and surface morphologies of both the as‐synthesized A‐Fe3O4 NPs and fabricated MMMs were examined using advanced characterization techniques. The quasi‐spherical A‐Fe3O4 NPs had an average particle size of 12 nm and a Brunauer–Emmett–Teller surface area of 131.38 m2/g. Analysis by Fourier transform infrared and Raman spectroscopy confirmed the presence of NH2 and OH functional groups grafted onto the Fe3O4 NPs. The incorporation of higher loadings of A‐Fe3O4 NPs in the membrane matrix significantly improved the adsorptive ability and hydrophilicity of the adsorbent, leading to improved membrane water permeance, adsorption rate, and adsorption‐filtration properties. The water contact angle decreased from 70.7° to 63.2°, and the flux increased from 239.9 to 443.8 L/m2.h, while overall membrane porosity increased from 43.4% to 51.9%.

Highly propylene-selective asymmetric mixed-matrix membranes by polymer phase-inversion in sync with in-situ ZIF-8 formation

Although mixed-matrix membranes (MMMs) have been extensively studied, their commercial applications have been hampered by scientific and engineering challenges. Herein, we report an innovative one-step MMM fabrication method that can put the commercialization of MMMs forward by overcoming most of the current challenges because it enables the rapid formation of high-performance asymmetric MMMs in a scalable manner. The method termed phase-inversion in sync with metal–organic framework (MOF) formation (PIMOF) involves a polymer film undergoing phase inversion and simultaneously ZIF-8 nanoparticles forming in-situ inside the polymer. The resulting MMMs show unexpectedly high C3H6/C3H8 separation performances (C3H6 permeance of ca. 7.5 GPU and C3H6/C3H8 separation factor of ca. 107), which is attributed mostly to the high effective ZIF-8 loading (>50 wt%) and the enhanced molecular sieving effect of the unusually small sub-5 nm ZIF-8 filler nanoparticles by restricted linker motion.

Halloysite nanotubes for regulating thermodynamics and kinetics of polysulfone/poly (ethylene-co-vinyl alcohol) membranes with enhanced permeability

Controlling membrane morphology is crucial to improving the mechanical strength (MS) and hydrophilicity of porous membranes. Here we report on the fabrication of mixed matrix membranes (MMMs) free of macrovoids via non-solvent-induced phase separation (NIPS). Hydrophilic Halloysite nanotubes (HNTs) and poly (ethylene-co-vinyl alcohol) (EVOH) were mixed with Hydrophobic polysulfone (PSF) in the presence of polyethylene glycol (PEG) to fabricate MMMs. The results showed the formation of PSF/EVOH-MMMs with a spongy structure when the content of HNTs varied from 0.06- 0.12 wt.%, owing to the formation of strong hydrogen bonds between PSF, EVOH, PEG, and HNTs, confirmed by molecular dynamics (MD) simulations. The MS of MMMs with 0.12 wt.% HNTs was increased 2.2-fold (up to 6.22 MPa), while the contact angle (CA) was lowest at 47.42 ± 1.9°. In addition, the water permeability increased by a factor of 1.7 up to 419 L m−2 h−1 bar−1. The rejection rates of MMMs (M12) for oil and BSA were >90% and >95%, respectively. While the MMMs had > 90% flux recovery for both oil and BSA. We predict that this study will provide a method for controlling dope thermodynamics, formation dynamics, and morphology of MMMs while maintaining promising properties for improved separation performance.

The effect of filler loading and APTES treatment on the performance of PSf/SBA-15 mixed matrix membranes

Abstract The fabrication of mixed matrix membranes (MMMs) is of particular importance due to their advantages over neat membranes. The performance of MMMs is a function of the type and fraction of the nanoparticles in the membrane. Moreover, the proper interaction of the polymer and nanoparticles affects the MMMs performance. In this study polysulfone (PSf)/SBA-15 mesoporous silicas MMMs were prepared and their performance was evaluated for CO2/CH4 gas separation. SBA-15 mesoporous silicas were previously synthesized and functionalized with 3-aminopropyltriethoxysilane by post-synthesis treatment. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, N2 adsorption–desorption, and Brunauer–Emmett–Teller analysis was applied to examine the functional groups, morphology, and textural properties of the unmodified and modified mesoporous silica in the prepared membrane, respectively. The effects of modified and unmodified SBA-15 particle loading were investigated for the gas separation performance of PSf/SBA-15 membranes. The experimental results illustrate that a higher modified mesoporous silica loading leads to an increase in gas permeance and gas pair selectivity. The highest increase in permeability and selectivity was related to the incorporation of S2 and AP-S2 into the PSf matrix, respectively.

Controlled Covalent Functionalization of ZIF-90 for Selective CO2 Capture & Separation.

Mixed Matrix Membranes (MMM) with enhanced selectivity and permeability are preferred for gas separations. The porous metal-organic frameworks (MOFs) materials incorporated in them play a crucial part in improving the performance of MMM. In this study, Zeolitic imidazolate frameworks (ZIF-90) are selected to fabricate Polyetherimide (PEI) MMMs owing to their lucrative structural and chemical properties. This work reports new controlled post-synthetic modifications of ZIF-90 (50-PSM-ZIF-90) with ethanolamine to control the diffusion and uptake of CO2. Physical and chemical properties of ZIF-90, such as stability and presence of aldehyde functionality in the imidazolate linker, allow for easy modulation of the ZIF-90 pores and window size to tune the gas transport properties across ZIF-90-based membranes. Effects of these materials were investigated on the performance of MMMs and compared with pure PEI membranes. Performance of the MMMs was evaluated in terms of permeability of different gases and selective separation of CO2 and H2 gas. Results presented that the permeability of all membranes was in the following order, i.e., P(H2) &gt; P(CO2) &gt; P(O2) &gt; P(CH4) &gt; P(C2H6) &gt; P(C3H8) &gt; P(N2), demonstrating that kinetic gas diffusion is the predominant gas transport mode in these membranes. Among all the membranes, permeability of pure PEI membrane was highest for all gases due to the uniform porous morphology. The pure PEI membrane showed highest permeability of H2, which is 486.5 Barrer, followed by 49 Barrer for O2, 29 Barrer for N2, 142 Barrer for CO2, 41 Barrer for CH4, 40 Barrer for C2H6 and 39.6 Barrer for C3H8. Results also confirm the superiority of controlled PSM-ZIF-90-PEI membrane over the pure PEI and ZIF-90-PEI membranes in CO2 and H2 separation performance. The 50-PSM-ZIF-90 PEI membrane exhibited a 20% increase in CO2 separation from methane and a 26% increase over nitrogen compared to the ZIF-90-PEI membrane. The 50-PSM-ZIF-90 PEI membrane showed 15% more H2/O2 separation and 9% more H2/CH4 separation than ZIF-90 PEI membrane. Overall, this study represents the role of controlled PSM in enhancing the property of new materials like ZIF and its application in MMMs fabrication to develop a promising approach for the CO2 capture and separation.

Fabrication of polysulfone mixed matrix membrane for wastewater treatment.

Recent development in separation technologies has envisioned a green and sustainable future that encouraged energy preservation and waste minimization. The concept of a clean future emphasizes on retrieval and reutilization of valuable products from waste streams to improve the water quality. Membrane-based separations are currently explored as an auspicious substitution over traditional separation processes. The present study is designed to purify water using aluminum and gallium mixed matrix membranes from toxic metals (Lead and Mercury) and dyes (Rhodamine B, and Reactive Blue-4). Facile protocol i.e., immersion precipitation phase inversion method was used for the fabrication of mixed matrix membrane. The aluminium and gallium hybrids act as a filler and create heterogeneity and hydrophilicity within the membrane, affirming better water permeability and mechanical strength. The performance of fabricated mixed matrix membranes is evaluated using a lab-based dead-end membrane filtration unit. The result showed 30-71% rejection of Mercury, 24-65% rejection of Lead, 12-66% rejection of Reactive Blue-4, and 15-80% rejection of Rhodamine B.

Machine learning aided high-throughput prediction of ionic liquid@MOF composites for membrane-based CO2 capture

Ionic liquid encapsulated metal-organic framework ([email protected]) composites as promising filler used for mixed matrix membranes (MMMs) fabrication to break the trade-off limitation. However, discovering appropriate [email protected] composites effectively and cost-efficiently still faces a great challenge. In this study, we first construct the filler database consisting of 8167 [email protected] composites by inserting [NH2-Pmim][Tf2N] molecule into computation-ready, experimental metal-organic frameworks (CoRE MOFs). Using molecular simulation, we identified the best [email protected] composites based on different metrics and revealed gas separation mechanism. Working with RF model (R2 > 0.72), we uncover that the AV and gASA are key factors in predicting the membrane selectivity and CO2 permeability, respectively. The [NH2-Pmim][Tf2N]@ZIF-67 predicted can be as one of candidates for MMMs fabrication. The experimental results show that CO2 permeability (9536 Barrer) and CO2/N2 selectivity (31.1) of [NH2-Pmim][Tf2N]@ZIF-67/PIM-1 have 121.3% (37.6%) and 32.6% (38.8%) enhancements compared with unfilled PIM-1 (ZIF-67/PIM-1), surpassing the updated CO2/N2 Jansen/McKeown upper bound. Our computational study could offer effective prediction and may trigger experimental efforts to accelerate development of novel [email protected] composites used for fabricating MMMs with excellent performance.

Fabricating a ZIF‐8@Polydimethylsiloxane(PDMS)/PVDF mixed matrix composite membrane for separation of ethanol from aqueous solution via vapor permeation

AbstractTo date, vapor permeation (VP) technology has been attracted increasing attentions in ethanol fermentation process, in which the improvement of membrane performance is critical. In this study, zeolitic imidazolate frameworks (ZIF‐8) was successfully synthesized and chosen as incorporating nanofillers for fabrication of mixed matrix membrane (MMMs) using polydimethylsiloxane (PDMS) as the matrix. A simple modified “prime” method with higher viscosity of coating solution was implemented for preventing agglomeration of ZIF‐8 during membrane preparation process. A thin ZIF‐8@PDMS layer of 5.4 μm was obtained and firmly coated on a PVDF porous substrate to form the robust composite membrane structure. The chemical structure, morphologies, surface properties, and solvent uptakes of the resultant membrane were investigated compared with pristine PDMS/PVDF membrane. The VP performance for separation of ethanol/water binary solution in the concentration range of fermentation broth (1∼7 wt %) were tested and discussed by comparison of the ZIF‐8@PDMS/PVDF MMM and pristine PDMS/PVDF membrane. The trans‐membrane flux, separation factor, ethanol permeability, and membrane selectivity were all promoted by the embedded ZIF‐8 nanofillers.

Influence of various shapes of alumina nanoparticle in integrated polysulfone membrane for separation of lignin from woody biomass and salt rejection

Lignin valorization is essential in proposing an economic perspective as a raw material for valuable compounds. The bio-refineries require adequate processing to improve the high purity of lignin. Meanwhile, nanofiltration is fascinated attention to obtain high purity value-added products. The effect of alumina nanoparticles on the fabrication of mixed matrix membranes (MMM) has contributed to improvising filtration performance. However, incorporating nanoparticles is a significant issue regarding appropriate size and shape integrated into membrane for better filtration efficiency. The influence of shapes of alumina nanoparticles has been investigated into polysulfone (PSf) membranes for salt and lignin separation. The morphology of alumina was tailored with spindle, cubic, and spherical shapes synthesized at a different calcination temperature of 250, 500, 700 and 900 °C, respectively. The phase transitions were confirmed in X-ray diffraction (XRD) analysis, and the shape of the nanoparticles was observed in a high–resolution transmission electron microscope (HRTEM). The separation efficiency of membranes was tested with salt rejection using sodium sulfate, calcium chloride, potassium sulfate, and sodium chloride. The lignin was extracted from prehydrolysed sawdust, and the synthetic lignosulfonic acid sodium salt solution was separated. The higher lignin rejection of 98.6% and 97.9% were obtained for cubic shaped gamma phase alumina mixed matrix membrane. The high rejection of lignin occurred due to narrow pores channels that could resist the transfer of lignin through the membrane. The results proved that the controllable organization of PSf/alumina mixed matrix membranes could apply for lignocellulose compounds with good efficiency.

In-situ growth of UiO-66-NH2 in porous polymeric substrates at room temperature for fabrication of mixed matrix membranes with fast molecular separation performance

In-situ growth of UiO-66-NH2 in ordinary porous polymeric substrates offers promising opportunities to eliminate interfacial defects in mixed matrix membranes (MMMs). However, this strategy is still hard to be realized because conventional hydrothermal synthesis of UiO-66-NH2 involves harsh conditions (e.g., high temperatures, and polar aprotic solvents), which are destructive to ordinary polymer. Herein, UiO-66-NH2 was in-situ grown in polymeric substrates under room temperature via a successive immersion of a porous polyether sulfones substrate in a Zr4+ formic acid/ethanol solution and a 2-aminoterephthalic acid ethanol/formic acid/water solution. Attenuated total refraction Fourier transform infrared and X-ray diffraction characterizations demonstrated the successful incorporation of UiO-66-NH2 in the substrate. The optimized membrane possessed a high pure water permeance of 209.5 L-2h−1 bar−1 and rejections higher than 99.5% towards small molecules of Congo Red, xylene brilliant cyanin G, and Rose Bengal sodium salt. More importantly, after a 5-day immersion in water or an intense ultrasonication treatment, the membrane showed no significant change in separation performance, suggesting its excellent stability. The novel strategy regarding MMMs with UiO-66-NH2in-situ growth disclosed in this study paves the way to develop advanced UiO-66-NH2 membranes toward sustainable molecular separation in environmental applications.

Fabrication of mixed matrix membranes with regulated MOF fillersviaincorporating guest molecules for optimizing light hydrocarbon separation performance

Guest molecules were incorporated into MOF fillers to construct MMMs withPIM-1for enhanced gas separation performance.

Synthesis of ZIF‐94 from Recycled Mother Liquors: Study of the Influence of Its Loading on Postcombustion CO2 Capture with Pebax Based Mixed Matrix Membranes

AbstractGlobal energy demand is met in large part, by burning of fossil fuels, which is causing global warming. Mixed matrix membranes (MMMs) with metal organic frameworks (MOFs) as fillers are an interesting alternative for capturing post combustion CO2 which would make the energy sector sustainable. This research is focused on the synthesis of MOF ZIF‐94 from the recycling of its mother liquors and the incorporation of synthesized MOF into a Pebax MH 1657 for MMM fabrication. The pH and the temperature of ZIF‐94 synthesis are modified and monitored and this results in various nanoparticle diameters (average particle size in the range of 41 ± 8–180 ± 73 nm). Incorporation of ZIF‐94 significantly improves the performance of the bare Pebax MH 1657 membrane. The maximum CO2/N2 selectivity and CO2 permeability are obtained for 10 wt% ZIF‐94 loading in 9 wt% (polymer concentration in 70/30 (v/v) ethanol/water solution) Pebax MH 1657 matrix being 36 ± 7 (71% increment compared to bare membrane) and 137 ± 31 Barrer (80% improvement), respectively.