Search

The current state of reticular chemistry enables the synthesis of a wide range of highly porous nanomaterials for gas separation, including metal‐organic frameworks (MOFs), covalent organic frameworks (COFs), porous organic cages (POCs), metal‐organic cages (MOCs), and polyhedra (MOPs). This perspective focuses on membrane technology, a key player in energy‐efficient gas separations. It explores the world of reticular materials, taking a glance at tiny pore windows with narrow openings, which are ideal for high‐resolution molecular sieving, and how to design them. Promising concepts in this field are membranes consisting of neat materials, but also mixed matrix membranes, where polymeric films incorporate reticular fillers, creating cost‐efficient membranes. This article sheds light on the potential use of reticular materials as membrane components. The reticular synthesis of MOFs offers the ability to separate gas molecules with minimal size differences effectively. For COFs, the crucial factor lies in reducing their pore size, preferably through functional group modifications. Porous cage compounds can achieve fine distribution from homogeneous dispersions into polymers making them excellent candidates for mixed matrix membranes. This perspective provides strategies and guiding principles for the future of reticular nanomaterials‐based membranes, addressing the pressing need for advanced and efficient separation technologies. [ABSTRACT FROM AUTHOR]

Mixed matrix membranes (MMMs), an important class of organic-inorganic nanocomposite membranes, were developed to overcome some of the limitations of purely polymeric membranes. In this study to improve the separation performance of polyvinyl chloride (PVC) membranes, mixed matrix membranes (MMMs) were prepared from incorporating choline prolinate based ionic liquid (IL) in a the coke/metal-organic framework (MOF) (NH2-MIL-101(Cr)) as a filler in polyvinyl chloride (PVC), which can be viewed as a potential solution to the trade-off problem with polymeric membranes because of the combination of the processing versatility of polymers and the high gas separation capability. Coke/MOF/PVC and IL@AC/MOF/PVC MMMs with different filler loadings of 5, 10, and 15 wt% were prepared using solution casting method and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDX) analyses, and Brunauer-Emmett-Teller (BET) surface area test. The porous structure of MMMs nanocomposites causes to which coke/MOF composite effectively accelerate gas diffusion in the PVC matrix. The permeability date was measured at 288.15, 298.15, 308.15 and 318.15 K and pressure up to 4 bar for CO2 and N2. According to the outcome, the addition of the IL([Cho][Pro]) filler, the permeability of the AC/MOF/PVC MMMs is increased compared to the pure PVC membrane. The MMMs have the highest gas separation efficiency and performance above Robson's Upper Bound from 2008. [ABSTRACT FROM AUTHOR]

This study explores fabrication and characterization of mixed matrix membranes (MMMs) for gas separation, employing a cost‐effective solution casting method. Polycarbonate (PC) and polystyrene (PS) blends are combined with graphene oxide (GO) and zirconium dioxide (ZrO2) nanofillers, with and without a deep eutectic solvent (DES) obtained through hydrogen bond exchange. Various MMMs compositions (2–20 wt%) are systematically examined using diverse characterization techniques, including differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, porosity determination, and water contact angle analysis. The MMMs exhibit enhanced gas permeability and selectivity, surpassing conventional membrane materials. Notably, H2 gas permeability reaches outstanding levels, with the composition PC/PS‐DES‐GO/ZrO2 at 20 wt% (PBC20‐IV) demonstrating the highest value of 86.32 Barrer. This superior performance is attributed to the unique properties of ZrO2, increased sorption capacity of GO, and enhanced thermal stability due to DES. Permeability data for CO2, N2, O2, and CH4 also show significant values, aligning with the observed trends in H2 permeability. Robeson's plot for the H2/CO2 gas pair surpasses the 2008 upper bound, placing the MMMs in a novel category for gas separation membranes. The incorporation of DES‐modified nanofiller blend composites presents a promising strategy for the potential production of pure hydrogen. [ABSTRACT FROM AUTHOR]

The development of CO2 separation membranes with high permeability and high selectivity, as well as ultra-thin selective layers, has always been challenging. Herein, a molecular-scaled co-assembly strategy is employed to fabricate the Pebax-Mo132 (Pebax = polyether-block-amide copolymer; Mo132 = (NH4)42[Mo72VIMo60VO372(CH3COO)30(H2O)72]) membranes. The optimal self-standing membrane, Pebax-Mo132-5%, shows a CO2 permeability of ∼384 Barrer and an ultra-high ideal CO2/N2 selectivity of ∼244, outperforming most membranes reported in the literature. The CO2 permeability and ideal CO2/N2 selectivity are increased by 70% and 367%, respectively, compared with the pristine Pebax membrane. A thin-film composite membrane prepared by spin-coating technique on a support membrane with gutter layers also exhibits a CO2 permeance of 838 GPU and a CO2/N2 selectivity of 136. Such excellent performance can be attributed to the following reasons: (1) strong hydrogen bonding interactions between {Mo132} clusters and Pebax confer excellent interfacial compatibility to the mixed matrix membranes; (2) incorporation of hollow {Mo132} clusters into the Pebax molecular chain decreases the crystallinity of Pebax, and thereby accelerates the chain dynamics and increases the free volume of the membrane; (3) in situ diffuse reflectance infrared Fourier-transform spectroscopy demonstrates that the {Mo132} clusters can effectively catalyze the hydration reaction of CO2 and promote the transport of CO2; (4) furthermore, the 0.35 nm pores of the crown ether-type {Mo9O9} allow the accurate size sieving of CO2 (0.33 nm) and N2 (0.36 nm) molecules. [ABSTRACT FROM AUTHOR]

This study investigated the enhancement in bioethanol recovery from mixed matrix membranes (MMMs) by functionalizing zeolite framework-8 (ZIF-8) with imidazolate. This study focused on the separation of ethanol from low-concentration ethanol/water mixtures (typical post-fermentation concentrations of 5–10 wt%). Specifically, ZIF-8 was modified by the shell–ligand exchange reaction (SLER) with 5,6-dimethylbenzimidazole (DMBIM), resulting in ZIF-8-DMBIM particles with improved hydrophobicity, organophilicity, larger size, and adjustable pore size. These particles were incorporated into a PEBAX 2533 matrix to produce ZIF-8-DMBIM/PEBAX MMMs using a dilution blending method. The resulting membranes showed significant performance enhancement: 8 wt% ZIF-8-DMBIM loading achieved a total flux of 308 g/m2·h and a separation factor of 16.03, which was a 36.8% increase in flux and 176.4% increase in separation factor compared with the original PEBAX membrane. In addition, performance remained stable during a 130 h cycling test. These improvements are attributed to the enhanced compatibility and dispersion of ZIF-8-DMBIM in the PEBAX matrix. In conclusion, the evaluation of nanofiller content, feed concentration, operating temperature, and membrane stability confirmed that ZIF-8-DMBIM/PEBAX MMM is ideal for ethanol recovery in primary bioethanol concentration processes. [ABSTRACT FROM AUTHOR]

For the in situ growth method, the reaction time is important because increasing the reaction time may make it possible for the crystallized ZIF‐8 to fully cover the GO sheets; the excess of ZIF‐8 particles reduces the aspect ratio of the GO sheet. The reaction time will significantly change the morphology, affecting the composite's ability to absorb selective gas and, in turn, affect the gas selectivity. The present work identifies the reaction time for in situ growth of ZIF‐8 nanoparticles on GO sheets. The composite was synthesized at different reaction times of 2, 4, 6, and 8 h and incorporated into the PSF matrix. The fabricated membranes were characterized by FTIR, TGA, SEM, and XRD. The novel synthesized reaction time (6 h) was identified for better enhancement of CO2/CH4 separation. For pure gas studies, the results investigated that the CO2 permeability and CO2/CH4 selectivity were increased by 223% and 98%, respectively, compared with plain PSF membrane. In mixed gas (CO2/CH4) studies, the CO2 permeability and CO2CH4 selectivity were increased by 349% and 854%, respectively, compared with plain PSF membrane. Hence, the in situ growth method helps synthesize MOF@GO composites in the application of gas separation. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) are promising porous materials that have huge potential for gas separation when put in the membrane configuration. MOFs have huge potential due to certain salient features of the MOFs such as excellent pore size, ease of tuning the pore chemistry, higher surface area, and chemical and thermal stabilities. MOFs have been explored for various gas separation and storage applications. This review discusses various approaches for fabricating MOFs‐based membranes for the separation of H2 gas from a variety of feeds having various gases CO2, CO, N2, and CH4 as impurities. The emphasis has been put on three types of membranes for H2 separation which include MOFs‐based hollow fibrous/tubular/disk membranes, MOFs‐based mixed matrix membranes (MMMs), and MOFs‐based stand‐alone membranes. In addition, various challenges such as reducing inhomogeneity between MOFs and polymeric matrices have also been discussed. Similarly, the approaches to successfully decorating MOFs on different supports in different configurations have been explained. The possible ways of improving the MOFs‐based membranes for H2 have also been discussed. [ABSTRACT FROM AUTHOR]

In various industrial applications focusing on environmental sustainability, the purification of H2 from CO2-containing streams is crucial. Membrane-based separation processes are preferred over other gas separation techniques due to their superior efficiency and selectivity and lower energy consumption. Membranes composed of inorganic nanoporous materials, known for their uniform pore size distribution and high permeability, exhibit remarkable gas separation performance. Recently, two-dimensional (2D) nanomaterials with high surface area and tunable functional groups have gained attention for membrane-based gas separation applications, owing to their thermal and mechanical durability. Therefore, we carried out a simulation study at the nanoscale level encompassing multiple analytical viewpoints of 2D MXene membranes: (i) A collection of 730 MXene structures was evaluated for single gas H2/CO2 separation, and 700 of these surpassed the Robeson upper bound, indicating their significant potential for replacing conventional polymeric membranes. Moreover, VCrNF2, MoWCF2, Y2NO2, and Sc2NO2 nanomaterials were listed as potential membranes according to the predefined ranking criteria. (ii) The performance of mixed matrix membranes (MMMs) made of five different polymers and all MXene nanomaterials was calculated with Maxwell's model. (iii) The effect of interlayer distance of MXene nanosheets on H2/CO2 separation was examined over the top four MXene nanomaterials and experimentally highly studied Ti2CO2 MXene. The optimum interlayer distance was defined as 5.5 Å for effective separation. (iv) Finally, Y2NO2 and Ti2CO2 MXene membranes were compared in terms of concentration polarization. Y2NO2 is more susceptible to CO2-related concentration polarization, which hinders CO2 transport and improves H2/CO2 separation in single gas measurements. By examining MXene membranes for H2/CO2 separation in multiple aspects, we aimed to demonstrate their potential and further guide the experimental studies. [ABSTRACT FROM AUTHOR]

This study aimed to develop PSU membranes by adding different concentrations (zero, 0.5, 1.0, and 1.5 wt.%) of graphene nanoplatelets (GNP) during synthesis to evaluate the influence of GNP on membrane permeability, retention capacity, mechanical and chemical resistance, structure, and membrane chemistry. All produced membranes had a hydrophilic character, which reduced with the increase in GNP content (72.4° to 84.4°) and a decrease in thickness (200.8 µm to 109.3 µm). Adding GNP did not affect the membranes' mechanical properties and chemical resistance. GNP addition increased the compaction time (from 5.35 h to 35.62 h) and reduced membrane permeability (from 6.78 L∙m−2∙h−1∙bar−1 to 0.10 L∙m−2∙h−1∙bar−1) of pure water. The obtained membranes were classified as ultrafiltration membranes, with an egg albumin retention rate (45 kDa) above 80 %. A greater retention of egg albumin was observed with the highest amount of GNP (1.5 wt.%). Adding GNP stabilized the polymeric matrix (PSU) properties, including increased chemical and mechanical resistance, interaction between the polymer and the nanofiller, and hydrophobic characteristics with a smaller thickness. This study contributed to Brazilian research in membrane synthesis, promoting the investigation of outstanding materials in the field of nanotechnology, in particular, the use of GNP as an additive in the preparation of mixed matrix membranes for water treatment. [ABSTRACT FROM AUTHOR]

Abstract Mixed matrix membranes (MMMs), an important class of organic-inorganic nanocomposite membranes, were developed to overcome some of the limitations of purely polymeric membranes. In this study to improve the separation performance of polyvinyl chloride (PVC) membranes, mixed matrix membranes (MMMs) were prepared from incorporating choline prolinate based ionic liquid (IL) in a the coke/metal-organic framework (MOF) (NH2-MIL-101(Cr)) as a filler in polyvinyl chloride (PVC), which can be viewed as a potential solution to the trade-off problem with polymeric membranes because of the combination of the processing versatility of polymers and the high gas separation capability. Coke/MOF/PVC and IL@AC/MOF/PVC MMMs with different filler loadings of 5, 10, and 15 wt% were prepared using solution casting method and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDX) analyses, and Brunauer-Emmett-Teller (BET) surface area test. The porous structure of MMMs nanocomposites causes to which coke/MOF composite effectively accelerate gas diffusion in the PVC matrix. The permeability date was measured at 288.15, 298.15, 308.15 and 318.15 K and pressure up to 4 bar for CO2 and N2. According to the outcome, the addition of the IL([Cho][Pro]) filler, the permeability of the AC/MOF/PVC MMMs is increased compared to the pure PVC membrane. The MMMs have the highest gas separation efficiency and performance above Robson’s Upper Bound from 2008.

Membrane technologies have developed as one of the main contributors to the resolution of water-related problems. This study seeks to examine the impact of active carbon nanoparticles (ACNPs) on the characterization and mechanical properties of polyethersulfone (PES) ultrafiltration membranes. The PES-AC composites were prepared using the phase inversion technique with a doctor blade by including ACNPs at varied weight percentages (0.01, 0.02, 0.03, 0.04 wt%). Produced membranes were characterized using FTIR, TGA, SEM, and XRD techniques, and the mechanical properties were evaluated using a tensile test, following the guidelines of the ASTM 638M-3 standard, utilizing a uniaxial universal testing machine. SEM images reveal that PES pure membranes consist of a porous bulk layer and dense skin layer. The addition of ACNPs decreased the pore size of the membranes with total thickness varying from 140 to 150 μm. Fourier-transform infrared spectroscopy (FTIR) indicated that with increasing ACNPs concentration, the peak intensities are related to C–C stretching bonds and acidic C–O groups. The XRD analysis showed that with higher ACNPs loading, there are a decrease in the amorphous phase of mixed matrix membranes (MMMs) and the highest intensity (2θ = 12.99°) at 2% ACNPs concentration. The tensile strength of the MMMs increased and reached an ideal value of 3.386 MPa when loaded with 2% ACNPs. Also, the optimum rate of tensile strain with 40% enhancement was achieved with 2% ACNPs compared with the pristine PES membrane. [ABSTRACT FROM AUTHOR]

Nano-organic hybrid materials (Al2O3-NOHMs) were synthesized with nano-alumina as the core, γ-(2,3-epoxypropyl) propyl trimethoxysiane (KH560) as the corona, and three of polyetheramine M2070, D2000, M1000 as the canopy, respectively. Al2O3-NOHMs were used as fillers to prepare MMMs with Pebax as substrate to improve the CO2 separation performance. The Al2O3-NOHMs were characterized by TEM and rheological properties. The results showed that the synthesized Al2O3-NOHMs were liquid-like and had a core-shell structure, which can effectively reduce Al2O3 agglomeration in the membrane. FT-IR analysis of MMMs showed that Al2O3-NOHMs and Pebax were physically blended, TGA indicated that Al2O3-NOHMs do not affect the thermal stability of the membrane, and XRD indicated that the addition of Al2O3-NOHMs destroyed the interchain hydrogen bond of Pebax and reduced the crystallinity of MMMs. The gas permeability of the membrane was tested under ideal gas conditions, compared with pure membrane, the CO2 permeability of Al2O3-NOHM(M2070)/Pebax MMMs and Al2O3-NOHM(D2000)/Pebax MMMs reached 137.15 Barrer (24.68%) and 147.52 Barrer (34.11%), and the selectivity of CO2/N2 reached 77.82 (58.84%) and 72.31 (47.59%) at 30°C and 0.3 MPa, respectively, surpassing 2008 Robeson upper bound. [ABSTRACT FROM AUTHOR]

Mixed matrix membranes (MMMs) could combine the advantages of both polymeric membranes and porous fillers, making them an effective alternative to conventional polymer membranes. However, interfacial incompatibility issues, such as the presence of interfacial voids, hardening of polymer chains, and blockage of micropores by polymers between common MMMs fillers and the polymer matrix, currently limit the gas separation performance of MMMs. Ternary phase MMMs (consisting of a filler, an additive, and a matrix) made by adding a third compound, usually functionalized additives, can overcome the structural problems of binary phase MMMs and positively impact membrane separation performance. This review introduces the structure and fabrication processes for ternary MMMs, categorizes various nanofillers and the third component, and summarizes and analyzes in detail the CO2 separation performance of newly developed ternary MMMs based on both rubbery and glassy polymers. Based on this separation data, the challenges of ternary MMMs are also discussed. Finally, future directions for ternary MMMs are proposed.

Mixed matrix PVDF polymeric membranes were incorporated with β–CD grafted graphene oxide (GO) nanocomposites (β–CD-g-GO) via nonsolvent induced phase separation method and used in the adsorption of congo red (CR) and methyl orange (MO) dyes. The incorporation of β–CD-g-GO (6 wt%) was found to improve the membrane physico-chemical properties and performance. The water content was increased by 24.26%, contact angle reduced from 84.17 to 62.97° while flux increased from 12.42 to 275.03 L m−2 h−1 bar−1. The membranes were able to remove 100% of CR at pH 7 and 99.4% of the MO dye at pH 5 within 240 min. The adsorption kinetics and isotherms were well fitted to the pseudo second-order kinetic model and Freundlich isotherm model respectively. These results indicated that the adsorption of both dyes occurred via chemisorption and in a multilayer on a heterogeneous surface of the membranes. According to these findings, it was concluded that the adsorption mechanism was due to hydrogen bonding interactions between nitrogen and hydroxyl groups, inclusion complexation introduced by β–CD molecules and electrostatic interactions, between the negatively charged oxygen-containing groups of the membrane and the positively charged nitrogen and azo-linkages of the dye molecules. PVDF/β–CD-g-GO membranes have shown excellent adsorption efficiency towards azo dyes. This work indicates that the embedding of adsorptive GO-β–CD nanocomposites in PVDF membranes can remove anionic dyes from wastewater treatment. [ABSTRACT FROM AUTHOR]

Mixed matrix membranes (MMMs) could combine the advantages of both polymeric membranes and porous fillers, making them an effective alternative to conventional polymer membranes. However, interfacial incompatibility issues, such as the presence of interfacial voids, hardening of polymer chains, and blockage of micropores by polymers between common MMMs fillers and the polymer matrix, currently limit the gas separation performance of MMMs. Ternary phase MMMs (consisting of a filler, an additive, and a matrix) made by adding a third compound, usually functionalized additives, can overcome the structural problems of binary phase MMMs and positively impact membrane separation performance. This review introduces the structure and fabrication processes for ternary MMMs, categorizes various nanofillers and the third component, and summarizes and analyzes in detail the CO2 separation performance of newly developed ternary MMMs based on both rubbery and glassy polymers. Based on this separation data, the challenges of ternary MMMs are also discussed. Finally, future directions for ternary MMMs are proposed. [ABSTRACT FROM AUTHOR]

Mixed matrix membranes (MMMs), which is polymeric matrix incorporated with inorganic filler materials, appear to be potential candidate for CO2 separation. Current work focuses on fabrication of MMMs incorporated with varying loading of small pore zeolite UZM-5 and modified UZM-5 for CO2/CH4 separation. Zeolite UZM-5 was firstly synthesized and then modified by using 3-aminopropyltriethoxysilane (APTES). MMMs was fabricated by incorporating zeolite UZM-5 and modified UZM-5 (NH2-UZM-5) into polysulfone (PSF) matrix. Both modified and unmodified zeolite UZM-5 were characterized via Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Field Emission Scanning Electron Microscope (FESEM) and Brunauer-Emmett-Teller (BET) analysis. The fabricated membranes were characterized using FTIR, XRD, TGA and FESEM analysis. The successful synthesis of zeolite UZM-5 was proven by XRD analysis. FESEM analysis of the membranes revealed that the successful the MMMs were successfully fabricated with even distribution of zeolites in the polymer matrix. In CO2 and CH4 gas permeation and separation study for the membranes, the highest CO2/CH4 ideal selectivity of 33.1 was obtained by the MMMs with 1 % NH2-UZM-5, which was a significant enhancement of 212 % in CO2/CH4 ideal selectivity as compared to the pristine PSF membrane.

As atmospheric CO2 levels continue to rise, contributing to the climate crisis, there is an increasing urgency to separate this gas from others and to expedite related research. Metal-Organic Frameworks (MOFs), known for their porosity and tunability, have already made significant impacts in this field, particularly to be used as part of a membrane material. This study introduces a novel method to enhance the CO2 separation capabilities of MOFs-based mixed matrix membranes (MMMs). Instead of taking the traditional approach by functionalizing the MOF's ligands or varying the metal or metal-oxo MOF nodes, we harness the properties of metal atoms by integrating them as central elements within porphyrinic MOF linkers through a simple post-metalation method. As a result, by incorporating the post-metalated MOF-525 as fillers into the 6FDA-DAM (6FDA: 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride; DAM: 2,4,6-trimethyl-1,3-diaminobenzene) polymer to fabricate MMMs, we effectively demonstrate improved CO2/N2 and CO2/CH4 gas separation capabilities of around 20 % without the necessity to use a very high MOF loading (only 2 wt%). Further analysis on the gas transport reveals that such a performance improvement mainly comes from the enhanced CO2 solubility, which might be attributed to the presence of the metal atoms in the post-metalated MOF 525. Lastly, in order to get a more comprehensive understanding, we also carry out a computational study as a tool to validate and predict the experimental results of our MMMs. This study then opens up the possibility to further investigate the efficacy of introducing various metal atoms in other porphyrinic MOFs when they are used as fillers to significantly boost the CO2 separation performance of MMMs.

Using porous materials to selectively adsorb H2O from natural gas is a promising method to dehydrate methane (CH4). The structure of a Zirconium metal‐organic framework (Zr‐MOF), namely, MIP‐202, features a high density of amino groups, which can produce strong hydrogen bonding with H2O molecules. MIP‐202 is cost‐effective, green and scalable, and it exhibits good chemical stability under various conditions. This work incorporated MIP‐202 nanoparticles into the high permeability polymer polyetherimide (PEI), and the obtained Mixed Matrix Membranes (MMMs) was used for the gas separation of H2O/CH4. It is found that MMMs loaded with 20 wt% of MIP‐202 demonstrated a high H2O/CH4 selectivity of 832.2, which was about 760 times of that of the pure PEI. This approach offers a new route to fabricate functional membranes for energy‐efficient gas separations. [ABSTRACT FROM AUTHOR]

As the atmospheric carbon dioxide (CO2) concentration rapidly rises, carbon capture, utilization, and storage (CCUS) is an emerging field for climate change mitigation. Various carbon capture technologies are in development with the help of adsorbents, membranes, solvent-based systems, etc. One of the main challenges in this field is the removal of CO2 from nitrogen (N2) gas. This paper focuses on mixed matrix membrane technology, for which the CO2/N2 separation performance is based on differences in gas permeations. Membrane separation and purification technologies are widely studied for carbon capture. Microporous adsorbents such as zeolites and metal organic frameworks (MOFs) for carbon capture have been attracting researchers' attention due to their highly porous structures, high selectivity values, and tunable porosities. Utilizing microporous adsorbents dispersed within a novel, blended polymer matrix, fourteen membranes were prepared with the commercial MOF ZIF-8, zeolite 13X, and kaolin, with methyl cellulose (MC) and polyvinyl alcohol (PVA), which were tested using a single gas permeation setup in this study. The addition of polyallylamine (PAH) as a chemisorbent was also investigated. These membranes were synthesized both with and without a polyacrylonitrile (PAN) support to compare their performances. MC was found to be an ideal polymeric matrix component to develop free-standing MMMs. At 24 °C and a relatively low feed pressure of 2.36 atm, a free-standing zeolite-13X-based membrane (MC/PAH/13X/PVA) exhibited the highest N2/CO2 selectivity of 2.8, with a very high N2 permeability of 6.9 × 107 Barrer. Upon the optimization of active layer thickness and filler weight percentages, this easily fabricated free-standing MMM made of readily available materials is a promising candidate for CO2 purification through nitrogen removal. [ABSTRACT FROM AUTHOR]

The use of zeolites as fillers in mixed matrix membranes (MMM) in gas separation is a well-studied subject. The difficulties to produce a membrane with high selectivity and low defects in the zeolite/polymer interface are well documented. Many researchers have reported that the functionalization of zeolite surface led to membranes with higher compatibility with zeolite/polymer via using silane groups, amine groups, or ionic liquids in the particles surface to improve the gas permeability and separation efficiency. This article aims to describe, summarize and discuss the use of amines, silanes and ionic liquids as surface modifiers. Those modifications lead to an increase in selectivity and in polymer/filler compatibility by increasing the dispersion of the particles in the polymeric matrix, which represents the most recent subjects in the development of MMMs. The performance results surpass by many times the efficiency of regular MMM synthesis. The work is focused specifically on MMMs using the silico-aluminophosphate SAPO-34 due its potential, diverging from general reviews, and focusing on a specific case discussing recent works and new ways to develop this theme through a deeper study. All possible SAPO-34 surface modifications are compared, and new possible membrane modifications and treatments are proposed. [ABSTRACT FROM AUTHOR]

The ability to efficiently separate CO2 from other light gases using membrane technology has received a great deal of attention due to its importance in applications such as improving the efficiency of natural gas and reducing greenhouse gas emissions. A wide range of materials has been employed for the fabrication of membranes. This paper highlights the work carried out to develop novel advanced membranes with improved separation performance. We integrated a polymerizable and amino acid ionic liquid (AAIL) with zeolite to fabricate mixed matrix membranes (MMMs). The MMMs were prepared with (vinylbenzyl)trimethylammonium chloride [VBTMA][Cl] and (vinylbenzyl)trimethylammonium glycine [VBTMA][Gly] as the polymeric support with 5 wt% zeolite particles, and varying concentrations of 1-butyl-3-methylimidazolium glycine, [BMIM][Gly] (5–20 wt%) blended together. The membranes were fabricated through photopolymerization. The extent of polymerization was confirmed using FTIR. FESEM confirmed the membranes formed are dense in structure. The thermal properties of the membranes were measured using TGA and DSC. CO2 and CH4 permeation was studied at room temperature and with a feed side pressure of 2 bar. [VBTMA][Gly]-based membranes recorded higher CO2 permeability and CO2/CH4 selectivity compared to [VBTMA][Cl]-based membranes due to the facilitated transport of CO2. The best performing membrane Gly-Gly-20 recorded permeance of 4.17 GPU and ideal selectivity of 5.49. [ABSTRACT FROM AUTHOR]

The permeability–selectivity trade‐off of membrane is a major challenge limiting the development of pervaporation (PV) technology. Rational design of high‐performance mixed matrix membranes (MMMs) has the potential to break off the trade‐off. Herein, a solvent‐assisted linker exchange‐based strategy is reported to introduce fluoroalkyl into metal–organic framework‐808 (MOF‐808). The pore size of fluorinated MOF‐808 can be adjusted with fluoroalkyl of different chain length (like trifluoromethyl and pentafluoropropyl). Then, the fluorinated MOF‐808/polyether block amide (PEBA) MMMs are prepared for the PV of n‐butanol/water. Compared with pristine PEBA membrane, 20 wt% 3F‐MOF‐808(P)/PEBA MMMs (3F = ‐CF3 group; P = postmodification method) exhibit 69% increase in permeation flux and 33% increase in separation factor in the PV of 2.5 wt% n‐butanol aqueous solutions at 70 °C. Based on Grand Canonical Monte Carlo and molecular dynamics simulations, fluorinated MOF‐808 shows better butanol affinity (pull effect) and stronger water repulsion ability (push effect). And the "push–pull effect" between fluorinated MOF‐808 with butanol/water is helpful to enhance the PV performance of MMMs. The application of "push–pull effect" provides a new strategy for the rational design of high‐performance MMMs, which is of great significance for the in‐depth research and application of PV technology. [ABSTRACT FROM AUTHOR]

Herein, adsorptive polyethersulfone/polylactic acid (PES/PLA) blends membranes with systematic concentrations of cellulose nanofibers (CNFs) (0.5–2.5 wt%) were developed via a modified phase inversion process for the enhanced removal of cationic methylene blue (MB) dye. To the best of our knowledge, this is the first time that such adsorptive membranes have been produced for potential use in wastewater treatment. The fabricated membranes were characterized for surface and cross‐sectional morphology (scanning electron microscope), surface roughness (atomic force microscope), functionality (Fourier‐transform infrared spectroscopy), thermal stability (thermal gravimetric analysis), wettability (contact angle measurements), antifouling behavior (flux recovery studies), and dye adsorption and reusability (adsorption and desorption tests). CNF incorporated membranes showed improved wetting properties, with contact angle decreasing from 76° in the pristine membranes to 48° in 2.5 wt% PES/PLA membranes. The membrane bulk porosity increased from 60.3% to 79.23%, while the pure water flux increased from 210.8 to 399.12 Lm−2 h−1. At optimal conditions, CNF‐modified membranes removed >98% of MB compared with 8% removal by the pristine membranes. After five cycles of adsorption and desorption, the membrane with 2 wt% CNFs achieved over 70% dye removal showing excellent reusability properties. Adsorption followed pseudo‐second‐order and Freundlich models. The adsorption was attributed to electrostatic interactions between the negatively charged membrane surfaces and the positively charged dye molecules as well as through hydrogen bonding. Therefore, this work revealed that CNF‐modified PES/PLA membranes can be used as adsorbents for the enhanced removal of organic pollutants in water treatment applications. [ABSTRACT FROM AUTHOR]

Aggregation of filler particles during the formation of mixed matrix membranes is difficult to avoid when filler loadings exceed a 10–15 wt %. Such agglomeration usually leads to poor membrane performance. In this work, using a ZIF‐67 metal–organic framework (MOF) as filler along with surface modification of Ag4tz4 to improve processability and selective olefin adsorption, we demonstrate that highly loaded with a very low agglomeration degree membranes can be synthesized displaying unmatched separation selectivity (39) for C3H6/C3H8 mixtures and high permeability rates (99 Barrer), far surpassing previous reports in the literature. Through molecular dynamics simulation, the enhanced compatibility between ZIF‐67 and polymer matrix with adding Ag4tz4 was proven and the tendency in gas permeability and C3H6 selectivity in the mixed matrix membranes (MMMs) were well explained. More importantly, the membrane showed a wide range of pressure and temperature resistance, together with remarkable long‐term stability (>900 h). The modification method might help solve interface issues in MMMs and can be extended to the fabrication of other fillers to achieve high performance MMMs for gas separation. [ABSTRACT FROM AUTHOR]

Mixed matrix membranes (MMMs) are promising in ion separation due to the simple preparation process. However, traditional metal–organic framework and covalent organic framework fillers lack the solution processibility and show interfacial defects between polymer matrixes and fillers, resulting in unsatisfactory separation performance. Herein, a soluble porous organic cage (POC) (i.e., CC3) is used as the filler to fabricate a large scale (~2000 cm2) and interfacial gap‐free ionic polymer (HPABP)‐CC3 membrane by a facile co‐solvent casting and rapid crystallization method. The resultant HPABP‐CC3(15) membrane shows a high Cl− flux of 2.24 mol m−2 h−1 and a Cl−/SO42− selectivity of 12.67, which is 3.6 and 3.0 times that of the HPABP membrane, respectively. Moreover, the HPABP‐CC3 membranes possess excellent cyclic and long‐term stability during the electrodialysis process. Therefore, we provide a facile strategy to scale up POC MMMs with synergistically enhanced ion flux and selectivity and the possibility for potential industrial ion separations. [ABSTRACT FROM AUTHOR]

This study investigated the enhancement in bioethanol recovery from mixed matrix membranes (MMMs) by functionalizing zeolite framework-8 (ZIF-8) with imidazolate. This study focused on the separation of ethanol from low-concentration ethanol/water mixtures (typical post-fermentation concentrations of 5–10 wt%). Specifically, ZIF-8 was modified by the shell–ligand exchange reaction (SLER) with 5,6-dimethylbenzimidazole (DMBIM), resulting in ZIF-8-DMBIM particles with improved hydrophobicity, organophilicity, larger size, and adjustable pore size. These particles were incorporated into a PEBAX 2533 matrix to produce ZIF-8-DMBIM/PEBAX MMMs using a dilution blending method. The resulting membranes showed significant performance enhancement: 8 wt% ZIF-8-DMBIM loading achieved a total flux of 308 g/m2·h and a separation factor of 16.03, which was a 36.8% increase in flux and 176.4% increase in separation factor compared with the original PEBAX membrane. In addition, performance remained stable during a 130 h cycling test. These improvements are attributed to the enhanced compatibility and dispersion of ZIF-8-DMBIM in the PEBAX matrix. In conclusion, the evaluation of nanofiller content, feed concentration, operating temperature, and membrane stability confirmed that ZIF-8-DMBIM/PEBAX MMM is ideal for ethanol recovery in primary bioethanol concentration processes.

Mixed‐matrix membranes (MMMs) have the potential for energy‐efficient gas separation by matching the superior mass transfer and anti‐plasticization properties of the fillers with processability and scaling up features of the polymers. However, construction of high‐performance MMMs has been prohibited due to low filler‐loading and the existence of interfacial defects. Here, high MOF‐loaded, i.e. 55 wt %, MMMs are developed by a 'dormancy and double‐activation' (DDA) strategy. High MOF precursor concentration suppresses crystallization in the membrane casting solution, realizing molecular level mixing of all components. Then, the polymeric matrix was formed with uniform encapsulation of MOF nutrients. Subsequently, double‐activation was employed to induce MOF crystallization: the alkali promotes MOFs nucleation to harvest small porous nanocrystals while excessive ligands activate the metal ions to enhance the MOFs conversion. As such, quasi‐semi‐continuous mass transfer channels can be formed in the MMMs by the connected MOFs nanocrystals to boost the gas permeability. The optimized MMM shows significantly ameliorated CO2 permeability, i.e. 2841 Barrer, five‐fold enhancement compared with pristine polymer membrane, with a good CO2/N2 selectivity of 36. Besides, the nanosized MOFs intensify their interaction with polymer chains, endowing the MMMs with good anti‐plasticization behaviour and stability, which advances practical application of MMMs in carbon capture. [ABSTRACT FROM AUTHOR]

In this study novel type of mixed matrix membranes (MMMs) were prepared through phase inversion. This fabricated MMMs were impregnated with biochar (BC) and biochar-Fe 3 O 4 (FBC) composites for selective removal of As(V) ions from acid mine drainage through the adsorptive-filtration processes. Scanning electron microscopy (SEM) images revealed that the BC and FBC adsorbents had heterogeneous surface morphologies with varying particle diameters. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the existence of polar functional groups, which aided the improvements in the adsorptive removal of As(V) ions. BET surface area increased from 8.32 m2/g of pristine BC adsorbent to 19.90 m2/g for the FBC adsorbents. Pure water flux increased from 239.9 L/m2.h (M0) to 359.4 L/m2.h (M6), and the water contact angle decreased from 70.7° (M0) to 51.4° (M6). The maximum adsorption capacity achieved was 34.92 mg/g and 49.54 mg/g for BC and FBC MMMs, respectively, at pH 10. The adsorption isotherms and kinetics were analyzed using the Freundlich model and Pseudo-first-order model, respectively, which provided the best-fit to the experimental data. Consequently, the adsorption isotherm data indicated that the removal of As(V) ions was influenced by electrostatic interaction, hydrogen bonding, diffusion (pore filling), and inner-sphere complexation mechanisms. Furthermore, the leaching rate of FBC from membrane labelled M6 was investigated at various pH levels, showing rates of 2.01 µg/m2.h, 0.09 µg/m2.h, and 0.08 µg/m2.h at pH 2, pH 7 and pH 10, respectively. The decrease in leaching rate observed under neutral (pH 7) and basic (pH 10) conditions is ascribed to the improved stability of Fe 3 O 4 NPs within the membranes. The membrane containing 1.5 wt% of FBC demonstrated enhanced effectiveness in removing toxic metals not only for As (99.9 %) but also Cr (99.8 %). These findings indicate that the membrane has great potential towards the treatment of acid mine drainage. [Display omitted] • Pristine BC and FBC adsorbents were synthesized via pyrolysis and co-precipitation. • The primary adsorption mechanisms processes were electrostatic interaction, hydrogen bonding, diffusion and inner-sphere complexation. • PES/BC and PES/FBC MMMs can be regenerated three times without losing its adsorption capacity. • PES/BC and PES/FBC MMMs showed high effectiveness removal efficiencies of 99.9 % and 99.8 % for As and Cr. [ABSTRACT FROM AUTHOR]

Membrane‐based separation can offer significant energy savings over conventional separation methods. Given their highly customizable and porous structures, metal–organic frameworks‐ (MOFs) are considered as next‐generation membrane materials that can bring about high separation performance and energy efficiency in various separation applications. Yet, the enormously large number of possible MOF structures necessitates the development and implementation of efficient modeling approaches to expedite the design, discovery, and selection of optimal MOF‐based membranes via directing the experimental efforts, time, and resources to the potentially useful membrane materials. With the recent developments in the field of atomic simulations and artificial intelligence methods, a new era of membrane modeling has started. This review focuses on the recent advances made and key strategies used in the modeling of MOF‐based membranes and highlight the huge potential of combining atomistic modeling of MOFs with machine learning to explore very large number of MOF membranes and MOF/polymer composite membranes for gas separation. Opportunities and challenges related to the implementation of data‐driven approaches to extract useful structure–property relations of MOF‐based membranes and to produce design principles for the high‐performing MOF‐based membranes are discussed. [ABSTRACT FROM AUTHOR]

Environmental concerns about chemical and biological pollution of water are of alarming proportions. Therefore, various polymeric membranes with improved mechanical and physico-chemical qualities for water treatment were developed using mixed matrix membranes (MMMs) or nanoparticles (NPs) embedded with the membranes. However, the problem of fouling and consequent higher operating and membrane replacement costs are barriers to the use of membrane technology. Therefore, a deeper comprehension of membrane fouling is not only essential for finding solutions but also a crucial factor in the development of membrane technology. The conventional blending modification would result in a large number of nanoparticles in the polymer matrix. In reality, the aggregation of nanoparticles in composite membranes is a considerable issue and would result in unfavorable changes to the features of the membrane (e.g. decreased water flux, weakened mechanical strength). In this review, it was looked into the effect of an optimal concentration of the hydrophilic nanoparticle additions to avoid the aggregation of nanoparticles in composite membranes and the reduced of using high amounts of valuable and costly nanoparticles in the membranes production and to obtain better results. The influence of the additives, such as (carbon nanotubes (CNTs), silica (SiO2), titanium dioxide (TiO2), zinc oxide (ZnO), aluminum oxide (Al2O3), and graphene oxide (GO), etc.) was investigated. [ABSTRACT FROM AUTHOR]

Hydrogen (H 2) energy meets the demand for green and efficient energy; therefore, hydrogen generation, purification, and separation are required. Membrane technology produce ultrapure hydrogen gas using less energy, allowing the process to run continuously. For preparing H 2 selective membranes, palladium (Pd) is a potential material because of its high affinity toward H 2 absorption. This work modified natural polysaccharide guar gum matric with natural chitosan polymer. The crosslinking of both the polymer improves the tensile strength and elongation at break (%). The composite polymer membrane enhances the separation performance of CO 2 /N 2 by 95.35% and CO 2 /H 2 by 34.29%. Further improvements in CO 2 /H 2 , the Pd nanoparticles are incorporated into the composite polymer matrix (GG/CH). The gas permeability data shows a drastic reduction in H 2 permeability by incorporating Pd-nanoparticles. In-room temperature, the selectivity of CO 2 /H 2 was obtained 13.06. The morphology of membranes and the presence of Pd nanoparticles in the membrane is characterized by SEM-EDS for confirmation of Pd nanoparticle. • Biopolymer (guar gum and chitosan) was used for fabricating a membrane. • The membrane was fabricated via the solution casting method. • The developed membrane is modified with Pd nanoparticle. • Implementing fabricated GG/CH/Pd MMMs for gas separation is explored. • The CO 2 /H 2 selectivity of GG/CH/Pd MMMs obtained at 13.06. [ABSTRACT FROM AUTHOR]

Membrane separation is one of the techniques used for biogas upgradation. Mixed matrix membranes (MMMs) are currently being explored to overcome the trade‐off of selectivity‐permeability inherent in polymer membranes used for gas separation. A significant challenge associated with MMMs is the poor polymer‐metal–organic framework (MOF) filler interfacial compatibility, reducing the selectivity or permeability of gas. To address this issue, the present study focuses on the effect of the amine functionalization of ZIF‐8 to enhance the CO2 gas permeation without reducing the CO2/CH4 selectivity. MMMs were fabricated using unmodified ZIF‐8 and amine‐modified ZIF‐8 nanofillers dispersed in polysulfone at 5, 10, and 15 wt% loadings. MMMs were characterized by FTIR, DSC, TGA, and FESEM. X‐ray diffraction and FTIR analysis was conducted to verify the amine modification of ZIF‐8. Further, the performance of MMMs was tested with pure gasses (CO2 and CH4) and a model mixture of CO2 and CH4. In the mixed gas permeation test, the 10 wt% ZIF‐8 MMM exhibited the highest CO2 permeability of 25.4 Barrers, while 15 wt% NH2‐ZIF‐8 MMM exhibited the highest selectivity of 13.5. Notably, the ZIF‐8 MMMs demonstrated a 148% increase in CO2/CH4 selectivity, whereas the NH2‐ZIF‐8 MMMs exhibited a 155% increase compared to the pure polysulfone membrane. [ABSTRACT FROM AUTHOR]

The use of ionic liquid [emim][Tf2N] as an additive in polyethersulphone (PES) and nano-sized silico-aluminophosphate-34 (SAPO-34) mixed matrix membrane was studied through the incorporation of different amounts of [emim][Tf2N] in the membrane composition, as presented in this work, varying from 10 to 40 wt%. Through gas permeation tests using CO2 and N2, the membrane composition containing 20 wt% [emim][Tf2N] led to the highest increase in CO2 permeability and CO2/N2 selectivity. The use of low concentrations of additive (10–20 wt%) promoted a state called antiplasticization; in this state, the permeability was even more regulated by the kinetic diameter of the species which, in this work, permitted achieving a higher CO2/N2 selectivity while increasing the CO2 permeability until an optimal condition. [emim][Tf2N] also promoted a better dispersion of SAPO-34 particles and an increase in the flexibility of the polymeric matrix when compared to a film with the same composition without [emim][Tf2N]. Moreover, the characterizations corroborated that the inclusion of [emim][Tf2N] increased the zeolite dispersion and improved the polymer/zeolite compatibility and membrane flexibility, characterized by a decrease in glass transition temperature, which helped in the fabrication process while presenting a similar thermal resistance and hydrophilicity as neat PES membrane, without affecting the membrane structure, as indicated by FTIR and a contact angle analysis. [ABSTRACT FROM AUTHOR]

In this study, TpDMB-COPs, a specific class of covalent organic polymers (COPs), was synthesized using Schiff-base chemistry and incorporated into a polyvinylidene fluoride (PVDF) polymer for the first time to prepare COPs mixed matrix membranes (TpDMB-COPs-MMM). A membrane solid-phase extraction (ME) method based on the TpDMB-COPs-MMM was developed to extract trace levels of six sulfonamides from human urine identified by high-performance liquid chromatography (HPLC). The key factors affecting the extraction efficiency were investigated. Under the optimum conditions, the proposed method demonstrated an excellent linear relationship in the range of 3.5–25 ng/mL (r2 ≥ 0.9991), with the low limits of detection (LOD) between 1.25 ng/mL and 2.50 ng/mL and the limit of quantification (LOQ) between 3.50 ng/mL and 7.00 ng/mL. Intra-day and inter-day accuracies were below 5.0%. The method's accuracy was assessed by recovery experiments using human urine spiked at three levels (7–14 ng/mL, 10–15 ng/mL, and 16–20 ng/mL). The recoveries ranged from 87.4 to 112.2% with relative standard deviations (RSD) ≤ 8.7%, confirming the applicability of the proposed method. The developed ME method based on TpDMB-COPs-MMM offered advantages, including simple operation, superior extraction affinity, excellent recycling performance, and easy removal and separation from the solution. The prepared TpDMB-COPs-MMM was demonstrated to be a promising adsorbent for ME in the pre-concentration of trace organic compounds from complex matrices, expanding the application of COPs and providing references for other porous materials in sample pre-treatment. [ABSTRACT FROM AUTHOR]

This study synthesized mixed matrix membranes (MMMs) using PEBAX® MH-1657 and ZIF-67 with varying particle concentrations (1, 3, and 5 wt%) to assess permeability and selectivity. ZIF-67 nanoparticles were prepared using the solvothermal method with methanol and characterized. Permeation tests were conducted at 10 and 15 bar using N2 and CO2. The analysis revealed ZIF-67 particles with an approximate diameter of 280 nm and confirmed characteristic sodalite peaks. The ideal CO2/N2 selectivity reached 67 (CO2 permeability = 132 ± 3.5 Barrer) at 15 bar. The impact of ZIF-67 varied with pressure and composition; at 10 bar, CO2/N2 selectivity decreased compared to pure PEBAX®; however, at 15 bar, the 1 wt% ZIF-67 membrane exhibited superior selectivity, surpassing Robeson's upper bound. The results indicate that ZIF-67 enhances the permeability and selectivity of PEBAX®, with superior performance observed at lower concentrations.

The permeability–selectivity trade‐off of membrane is a major challenge limiting the development of pervaporation (PV) technology. Rational design of high‐performance mixed matrix membranes (MMMs) has the potential to break off the trade‐off. Herein, a solvent‐assisted linker exchange‐based strategy is reported to introduce fluoroalkyl into metal–organic framework‐808 (MOF‐808). The pore size of fluorinated MOF‐808 can be adjusted with fluoroalkyl of different chain length (like trifluoromethyl and pentafluoropropyl). Then, the fluorinated MOF‐808/polyether block amide (PEBA) MMMs are prepared for the PV of n‐butanol/water. Compared with pristine PEBA membrane, 20 wt% 3F‐MOF‐808(P)/PEBA MMMs (3F = ‐CF3 group; P = postmodification method) exhibit 69% increase in permeation flux and 33% increase in separation factor in the PV of 2.5 wt% n‐butanol aqueous solutions at 70 °C. Based on Grand Canonical Monte Carlo and molecular dynamics simulations, fluorinated MOF‐808 shows better butanol affinity (pull effect) and stronger water repulsion ability (push effect). And the “push–pull effect” between fluorinated MOF‐808 with butanol/water is helpful to enhance the PV performance of MMMs. The application of “push–pull effect” provides a new strategy for the rational design of high‐performance MMMs, which is of great significance for the in‐depth research and application of PV technology.

In order to address the limitation of low flux in ultrafiltration (UF), a suitable additive is introduced into the base polymer to modify the membrane morphology, thereby enhancing flux rates. In this study, chamomile leaf nanoparticles (Chm NPs) were investigated as a novel green material for utilizing in UF membrane synthesizes. To enhance comprehension of the influence of Chm on the synthesis of PES UF membranes, a series of membranes were fabricated by including different quantities of Chm into the casting solution; (0, 0.5, 1.5, and 2 wt. %.). The synthesized membranes were fully characterized, through the porosity, pore size, hydrophilicity, membrane morphology, and UF efficiency. Manufactured PES/Chm membranes demonstrated significantly increased permeate water flux (PWF) (up to 498 kg/m2 h), which was four times that of the pristine PES membrane (116 kg/m2 h), besides that the bovine serum albumin (BSA) and Congo red dye (CR) rejection of PES/Chm membranes was still kept high. The enhanced PWF was mostly due to the more porous membrane structure and increased hydrophilicity. Meanwhile, the higher surface hydrophilicity of the PES/Chm membranes resulted in greater antifouling performance and the high flux recovery ratio (FRR) of 93 %. Based on the results of this research, the Chm may be used as a novel green additive with substantial application potential in the fabrication of UF membranes wastewater treatment.

Water pollution remains a critical concern, one necessitated by rapidly increasing industrialization and urbanization. Among the various strategies for water purification, membrane technology stands out, with polyethersulfone (PES) often being the material of choice due to its robust mechanical properties, thermal stability, and chemical resistance. However, PES-based membranes tend to exhibit low hydrophilicity, leading to reduced flux and poor anti-fouling performance. This study addresses these limitations by incorporating titanium dioxide nanotubes (TiO2NTs) into PES nanofiltration membranes to enhance their hydrophilic properties. The TiO2NTs, characterized through FTIR, XRD, BET, and SEM, were embedded in PES at varying concentrations using a non-solvent induced phase inversion (NIPS) method. The fabricated mixed matrix membranes (MMMs) were subjected to testing for water permeability and solute rejection capabilities. Remarkably, membranes with a 1 wt% TiO2NT loading displayed a significant increase in pure water flux, from 36 to 72 L m2 h−1 bar−1, a 300-fold increase in selectivity compared to the pristine sample, and a dye rejection of 99%. Furthermore, long-term stability tests showed only a slight reduction in permeate flux over a time of 36 h, while dye removal efficiency was maintained, thus confirming the membrane’s stability. Anti-fouling tests revealed a 93% flux recovery ratio, indicating excellent resistance to fouling. These results suggest that the inclusion of TiO2 NTs offers a promising avenue for the development of efficient and stable anti-fouling PES-based membranes for water purification.

The membrane separation process lacks intrinsic permeation characteristics to compete with other separation technologies like adsorption, sedimentation, coagulation, skimming, and distillation. A mixed matrix membrane (MMM) is one of the strategies to improve the separation characteristics with embedded nanofillers particles. Zeolite imidazolate framework (ZIF) has a new subclass of inorganic–organic hybrid materials that are being introduced as new fillers for incorporation into the polymer matrix for various applications such as oily wastewater separation, wastewater treatment, natural gas dehydration, landfill gas upgrading, and mixed gas separation. In this experimental work, a metal-organic framework called ZIF-8 was synthesized and used as a filler for modification of MMMs and characterized with FTIR and SEM. ZIF-8 nanoparticles up to 5 wt% loading were added to PSF casting solution then the permeation characteristics of MMMs showed an improved result like the pure water flux of the modified membrane at 2.5 bar was increased up to 456.38 L/m2h. In the case of pure gas separation, at 5 wt% ZIF-8 loading in PSF, the pure gas CO2 permeability at 9 bar pressure had increased to 10.54 barrer. HIGHLIGHTS We have studied water and gas permeation characteristics incorporated with ZIF-8 containing mixed matrix membranes.; ZIF-8 was made as a gateway for quick transport of CO2 gas molecules and water molecules through the polymer matrix.; As per the observed results, higher permeability of the MMMs can be possible with higher loading of ZIF-8.;