Mixed Matrix Membranes Research Articles

Membranes fouling propensity of PSF/GO hollow fiber mixed matrix membranes for water treatment ultrafiltration application.

The study investigated the fouling propensity of polysulfone (PSF) hollow fiber (HF) mixed matrix membranes modified with 1.0 wt.% graphene oxide (GO). Using scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA), and mechanical assessments, the structural characteristics of both untreated and GO-modified PSF HF membranes were examined. Filtration experiments included pure water and model contaminants such as bovine serum albumin (BSA), humic acid (HA), E. coli, and oil-in-water emulsion. The GO-modified membranes demonstrated a significant enhancement in antifouling performance, recovering over 90% of their initial pure water flux with HA and oil, indicating high resistance to irreversible fouling. Additionally, the GO-modified membranes showed superior oil separation efficiency. However, fouling parameters for BSA were similar for both membrane types, suggesting that GO does not significantly affect membrane-BSA interactions. Both types of membranes displayed high retention capabilities for E. coli, with no noticeable improvement due to GO addition. This study highlights the potential of GO-modified PSF HF membranes in enhancing antifouling performance and oil separation efficiency.

Twinned Metal-Organic Framework Nanoplates for Hydrocarbon Separation Membranes.

Filler morphology control is critical for enhancing the gas separation performance of mixed matrix membranes (MMMs). A vertical transport channel using the crystal twinning phenomenon is designed on the zeolitic imidazolate framework (ZIF) nanoplate. Twinned ZIF-8 (TZIF-8) nanoplate is prepared by controlling the shape of ZIF-L from nanosheet to twinned flake, followed by conversion into the ZIF-8 phase. With the addition of TZIF-8 in 6FDA-DAM polymer, propylene/propane selectivity is dramatically enhanced, showing propylene permeability of 40 Barrer and propylene/propane selectivity of 82. The separation performance surpasses the performance of MMMs reported so far, and the selectivity is comparable to that of polycrystalline ZIF-8 membranes. A transport mechanism study using mathematical models implies that the percolated twin fillers create rapid and selective gas channels for desired molecules and substantial tortuous pathways for undesired molecules.

Polyethersulfone mixed matrix membranes modified with pore formers and Ag-titanate nanotubes: physicochemical characteristics and (bio)fouling study.

In the presented studies it was hypothesized that the modification of a polymeric membrane with a pore former and a hybrid nanomaterial composed of titanate nanotubes with deposited Ag nanoparticles (Ag-TNTs NPs) can protect the membrane from the microbial growth, and thus enhance its resistance to biofouling. Polyethersulfone (PES) membranes were prepared by the wet phase inversion, and polyvinylpyrrolidone (PVP) and poly(ethylene glycol) (PEG) were used as pore formers. The membranes were characterized in terms of morphology, topography, permeability, separation characteristics, and anti-(bio)fouling properties as well as antibacterial activity. The membranes modified with porogens and Ag-TNTs revealed improved hydrophilicity and water permeability compared to the unmodified membrane, from 58 to 66%. Moreover, the improvement in rejection of model dextrans and PEG upon application of the NPs was found. However, the use of PVP or PEG had a negative influence on the resistance to fouling by bovine serum albumin, i.e., ca. 35% of decline of permeate flux was noticed after 2h of ultrafiltration of BSA. On the contrary, both porogens and NPs contributed to biofouling mitigation. The introduction of pore formers had a positive effect on the inhibition of Escherichia coli growth by the membrane containing Ag-TNTs. The log reduction of bacteria varied from 3.17 to 3.3 in case of stirred and filtration system.

Enhancing CO2/N2 and CO2/CH4 Separation Properties of PES/SAPO-34 Membranes Using Choline Chloride-Based Deep Eutectic Solvents as Additives

CO2 separation is an important environmental method mainly used in reducing CO2 emissions to mitigate anthropogenic climate change. The use of mixed-matrix membranes (MMMs) arrives as a possible answer, combining the high selectivity of inorganic membranes with high permeability of organic membranes. However, the combination of these materials is challenging due to their opposing nature, leading to poor interactions between polymeric matrix and inorganic fillers. Many additives have been tested to reduce interfacial voids, some of which showed potential in dealing with compatibility problems, but most of them lack further studies and optimization. Deep eutectic solvents (DESs) have emerged as IL substitutes since they are cheaper and environmentally friendly. Choline chloride-based deep eutectic solvents were studied as additives in polyethersulfone (PES)/SAPO-34 membranes to improve CO2 permeability and CO2/N2 and CO2/CH4 selectivity. SAPO-34 crystals of 150 nm with a high surface area and microporosity were synthesized using dry-gel methodology. The PES/SAPO-34 membranes were optimized following previous work and used in a defined composition, using 5 or 10 w/w% of DES during membrane preparation. All MMMs were characterized by their ideal gas permeability using N2 and CO2 pure gasses. Selected membranes were also tested using CH4 pure gas. The results presented that 5 w/w%, in polymer mass, of ChCl–glycerol presented the best result over the synthesized membranes. An increase of 200% in CO2 permeability maintains the CO2/N2 selectivity for the non-modified PES/SAPO-34 membrane. A CO2/CH4 selectivity of 89.7 was obtained in PES/SAPO-34/ChCl-glycerol membranes containing 5 w/w% of this DES, which is an outstanding ideal separation performance for MMMs when compared to other results in the literature. FTIR analysis reiterates the presence of glycerol in the membranes prepared. Dynamic Mechanical Thermal Analysis (DMTA) shows that the addition of 5 w/w% of DES does not impact the membrane flexibility or polymer structure. However, in concentrations higher than 10 w/w%, the inclusion of DES could lead to high membrane rigidification without impacting the overall thermal resistance. SEM analysis of DES-enhanced membranes presented asymmetric final membranes and reaffirmed the results obtained in DMTA about rigidified structures and lower zeolite–polymer interaction with higher concentrations of DES.

Selective Extraction of Terbium Using Functionalized Metal–Organic Framework-Based Solvent-Impregnated Mixed-Matrix Membranes

Advancements in membrane separation techniques will expand the applications and requirements for highly specialized, inventive, efficient, and resistant separation materials. The selective separation of rare earth elements (REEs) is one of the expanding applications of membrane-based techniques, as their use is becoming more widespread. Membrane techniques are becoming increasingly desired as environmentally friendly, straightforward methods for treating wastewater and separating metals. For the separation of REEs, an innovative impregnated mixed-matrix membrane (IMMM) technique was developed in this study. It provides a selective, efficient, and reusable method that is suitable for industrial applications. Terbium was selectively adsorbed from other REEs using organophosphorus IMMM with a loading capacity of 113.2 mg/g in 3 h and was reused three times without destroying the initial membrane. Solvent impregnation is thought to offer specific chelation sites that are selective for terbium separation.

Boosting Hydrogen Transport in Mixed Matrix Membranes Through Continuous Spillover Via Pd‐Functionalized MOF Gel Networks

AbstractMembrane‐based gas separation offers notable energy efficiency benefits for hydrogen purification, yet it is often hindered by the inherent trade‐off between permeability and selectivity. To address this challenge, a novel mixed matrix membrane (MMM) design is presented to boost H2 separation performance via continuous hydrogen spillover mechanisms for the first time. The MMM incorporates a palladium‐functionalized ZIF‐67 gel (Pd@ZIF‐67 gel) network into a polymer of intrinsic microporosity (PIM‐1) matrix. The ZIF‐67 gel network serves as a uniform dispersion medium for palladium nanoparticles (Pd NPs), thereby generating a multitude of active sites. These exposed sites, in conjunction with the microporous structure of ZIF‐67, facilitate hydrogen dissociation and establish a continuous hydrogen spillover pathway throughout the membrane. This synergistic MMM design leads to substantial improvements in both hydrogen transport and selectivity. At an optimal loading of 28 wt% Pd@ZIF‐67 gel, the MMMs exhibit a H2 permeability of 3620 Barrer and a remarkable 417% enhancement in H2/CH4 selectivity (24.9), surpassing the 2008 upper bound. This approach paves the way for the development of advanced materials tailored for gas separation applications.

Developing a novel polysulfone/chitosan membrane incorporated with green synthesized CuO from aloe vera extract for toxic dye removal

AbstractThe environment and public health have been protected by the simple, non‐destructive, and ecologically benign process used for fabricating membranes. In this study, a low‐cost wastewater treatment membrane is made from raw materials followed by phase inversion approach. A typical organic pollutant that has earned a poor track record for gradually harming aquatic life. Thus, the membrane technology is used to minimize the water contaminated by dyes. To treat wastewater, a membrane was developed by combining green synthesized CuO nanoparticles with polysulfone (PS) and chitosan (CS). The developed membranes were analyzed using x‐ray photoelectron spectroscopy, contact angle, Fourier transform infrared, scanning electron microscopy, transmission electron microscope, and x‐ray diffraction techniques. The developed membrane, along with the nanoparticles and additives, confirmed its crystalline confirmation, hydrophilicity, arrangement of structures, and morphological modifications. CuO nanoparticles were prepared using aloe vera extract, and incorporated into a mixed matrix membrane was utilized for the congo red (CR) and methylene blue (MB) adsorption processes. The absorption capacity was analyzed via UV spectroscopy makes it potentially important for membrane performance. Therefore, the resulting membrane could be used as a substrate for dye removal applications.

Nano-sized MIL-101(Cr) MOF for CO2 separation: Crystal downsizing effects on adsorption and mixed matrix membranes

In this paper, nano-sized MIL-101(Cr) metal–organic framework (MOF) and the micro-sized one were synthesized. To reduce the average crystal size, a surfactant namely cetyltrimethylammonium bromide (CTAB) in its optimum amount (Cr3+:CTAB = 1:0.3) along with microwave heating (600 W, 30 min) were applied. The prepared MOFs were characterized by FESEM, EDS, PXRD, BET, FTIR, and TGA analyses. Moreover, CO2 and CH4 adsorption isotherms and kinetics were investigated at 298 K and equilibrium pressures up to 1 bar. The results revealed that the CO2/CH4 ideal adsorption selectivity was improved by 27.15 % for the downsized MOF, so-called MIL-101(Cr)/CTAB, compared to the micro-sized one. Furthermore, by incorporation of the MOFs into the Ultem® 1000 polymer, mixed matrix membranes (MMMs) were fabricated. The morphological analysis of the prepared membranes displayed proper dispersion and compatibility between the polymer and MOFs. The best separation performance was obtained for the MMM containing 20 wt% of the mesoporous MIL-101(Cr)/CTAB. For this MMM, the CO2 permeability and CO2/CH4 ideal perm-selectivity values were enhanced by ∼ 136 % and ∼ 18 %, respectively at 298 K and 4 bar, compared to the neat membrane.

Dha Tab-COF filled PEBAX mixed matrix membranes for effective CO2/CH4 separation

Covalent organic skeletons (COFs) have been widely used in gas separation due to their excellent pore structure, high crystallinity, and high specific surface area. In this work, Dha Tab-COF was synthesized by solvothermal method and filled in polyether block polyamide (PEBAX) to form mixed matrix membranes (MMMs). Various characterization methods such as Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and X-ray diffractometry (XRD) were used to characterize the structure of Dha Tab-COF as well as the MMMs. The effects of operating pressure, operating temperature and the content of Dha Tab-COF particles on the CO2/CH4 separation performance of the membranes were investigated. The best separation performance with a CO2 permeability of 295.8 Barrer and a CO2/CH4 selectivity of 21.6 was achieved when the Dha Tab-COF content is 2 wt%, which were 45.7% and 108.1% higher than that of the pure PEBAX membrane, respectively.

COF-5/Pebax mixed-matrix membranes with enhanced CO2 removal ability for ECCO2R system

Extracorporeal CO2 removal (ECCO2R) is a type of extracorporeal life support (ECLS) technology. It aims to remove carbon dioxide (CO2) from small flow of the blood and correct hypercapnia and related acidosis. The ECCO2R system removes CO2 retained in the patient’s body through the gas-blood exchange membranes, which in use, blood flows on the outside of the membrane, and the inside of the membrane is for gas flow. Existing ECCO2R system generally improves the emission rate of CO2 by the increase of the gas flow rate. However, there is a problem that O2 is simultaneously taken out, which will reduce the blood O2 concentration. Therefore, the gas-blood exchange membranes should not only increase the CO2 removal rate by the improvement of CO2/O2 selectivity, but also retain more O2 in the blood and then maintain the oxygen saturation of the blood. In present work, a method was proposed to fabricate COF-5/Pebax mixed matrix membranes (MMMs) on the PMP surface for enhancing CO2/O2 selectivity, which was increased from 0.96 to 5.57. The CO2 removal ability of COF-5/Pebax MMM was tested by blood circulation, and it was found that the CO2 removal effect was increased 10.9% than that of the pristine membranes. The O2 concentration was maintained at a higher level, about 1.69 times that of the pristine membranes. In contrast to the pristine PMP membrane, blood compatibility of COF-5/Pebax MMMs was improved because protein adhesion decreased by 44.75%. The results of cytotoxicity test and rabbit pyrogen test exhibited that the prepared COF-5/Pebax MMM presented great biosafety. Overall, the proposed COF-5/Pebax MMM has good performance in ECCO2R system and attractive potential for medical application.

Polydopamine-incorporated MOF membrane with hydrophilicity for effective oil/water separation and fouling-resistant model analysis and prediction

A large number of oil spills and oily wastewater are discharged, in the modern industrial production process, resulting in serious water pollution. Oily wastewater can be extremely harmful to ecosystems and human health. Oil-water separation has become a major challenge at present, and membrane separation has aroused more and more concern in recent years due to its high economic efficiency. This paper fabricated PES filtration membranes using the novel nanoparticlesbased on both metal–organic frameworks-5 (MOF-5) and polydopamine (PDA) layers as dopants, and then adequately explored the porosity, morphology, separation, hydrophilicity, and fouling-resistant performance of the resultant membranes. In addition, the prepared membranes were used for oil–water separation, including soybean-in-water, petroleum ether-in-water, and gasoline-in-water emulsions. MOF@PDA membranes exhibit high separation efficiency of up to 99.8%. Subsequently, membrane fouling mechanisms were investigated using the Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, and the molecular mode of interaction with the three oil–water emulsions with the membrane was compared. Newly prepared MOF@PDA membranes have better stability, fouling-resistant, and self-cleaning properties. Finally, an optimal machine learning model for oil–water separation efficiency was developed with a high prediction accuracy of 98%. The obtained results indicate that mixed matrix membranes exhibit excellent oil–water separation performance, demonstrating great application prospects in the remediation of oily wastewater.

Intensifying the CO2/N2 separation performance of PVAm membrane by amine-functionalized porous montmorillonite

Multilayered montmorillonite (MMT) exhibits the building block stacking in polymer matrix, which has tortuous transport passageways and a few CO2 affinity sites, thus mixed matrix membranes incorporated with MMT have low molecular recognition ability for CO2. Herein, the porous MMT (p-MMT) was initially prepared through the solid-phase desilication reaction, and then amine-functionalized p-MMT (P3.2@p-MMT) was synthesized by the electrostatic interaction between positively charged polyethyleneimine (PEI) and negatively charged p-MMT, in which PEI was confined within the pore. Subsequently, mixed matrix composite membranes (MMCMs) were developed by the dispersion of polyvinylamine (PVAm) and P3.2@p-MMT, as well as hydrophilic-modified polysulfone as a support. It was observed that P3.2@p-MMT was uniformly dispersed in polymer matrix, and two phases had good interfacial compatibility due to hydrogen bonding. As a result, the gas separation performance of as-prepared MMCMs achieved a CO2 permeance of 217 GPU with a CO2/N2 selectivity of 112.3, which were 2.97 and 2.45 times that of the pristine PVAm membrane, and 1.57 and 2.49 times that of MMCMs incorporated with p-MMT respectively. The excellent gas separation performance is attributed to the relatively straight transport passageways, which originates from P3.2@p-MMT. Moreover, the amine groups within the pore of P3.2@p-MMT facilitate CO2 transport in the MMCMs. In addition, as-prepared MMCMs had high stability during over 360 h-testing, which displayed an average CO2 permeance of 238 GPU with the CO2/N2 selectivity of 124.1 utilized a gas mixture as the feed gas.

Investigation of Ceria based Heterostructure Composite Mixed Matrix Membrane with Polybenzimidazole for Polymer Electrolyte Fuel Cell Application at High Temperature

In recent years Ceria based heterostructure composites are considered as one of the highest performing solid state ionic conductors, therefore we wanted to leverage the benefits of using these materials for high temperature Proton Exchange Membrane Fuel Cells (PEMFCs). In this study a Polybenzimidazole (PBI)/Ceria carbonate CHC (Ceria based heterostructure composite) membrane was prepared by drop casting method and tested as an electrolyte for a high temperature H2/Air PEMFC application in anhydrous condition. Inorganic composite of ceria and alkali metal carbonates (Li2CO3, Na2CO3) was prepared by solid state route to obtain Ceria carbonate CHC. X-Ray diffraction (XRD) study confirmed the formation of the heterostructure and their successful incorporation into the PBI membranes. Homogeneity of fillers inside the membrane was further verified by Energy Dispersive X-Ray Analysis (EDAX) and Scanning Electron Microscopy (SEM). 5wt% of inorganic powder induced inside the PBI fillers reduced the phosphoric acid uptake of composite membrane (∼17% less) compared to pristine PBI membrane, which ultimately resulted into a lower swelling and dimensional change of the composite membrane. Thermal robustness of the phosphoric acid doped composite and pristine PBI membranes was investigated by thermogravimetric analysis (TGA) which showed that the prepared membranes were gone under a less than 10% reduction in weight up till 200ºC, ensuring their validity of application in high temp PEM fuel cells. The added inorganic functionalities resulted in a slight increase in the proton conductivity of PA doped composite PBI membranes i.e., 42.3 mS cm-1 at 180 ºC while for pristine PBI membrane it is 36 mS cm-1 at same temperature. A single cell with composite PBI membranes outperformed a pristine PBI membrane resulted into a ∼120% higher peak power density i.e., 320.88 mW cm-2. The composite membrane also displayed the excellent durability and showed a less than 10-4 mV/h degradation in cell potential till 180 ºC.

Fine-tuning CO2 separation of mixed matrix membranes by constructing efficient transport pathways through the addition of hybrid porous 2D nanosheets

Fine-tuning CO2 separation of mixed matrix membranes by constructing efficient transport pathways through the addition of hybrid porous 2D nanosheets

Toward quantitative evaluations of interfacial compatibility of ZIF-8 based mixed-matrix membranes via molecular simulations

Toward quantitative evaluations of interfacial compatibility of ZIF-8 based mixed-matrix membranes via molecular simulations

Experimental and Simulation Study of Single-matrix, All-polymeric Thin-film Composite Membranes for CO2 Capture: Block vs Random Copolymers

High-performance, additive-free, all-polymeric thin-film composite (TFC) membranes were developed for CO₂ capture, focusing on a comparison between block and random copolymers (referred to as PTF) composed of hydrophobic poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) and CO2-philic polar poly(oxyethylene methacrylate) (POEM) chains. The PTF random copolymer, synthesized via free-radical polymerization (FRP), exhibited a disordered morphology. In contrast, the PTF block copolymer, synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, formed a well-ordered hexagonally packed cylindrical structure, creating an amphiphilic, microphase-separated nanostructure. Molecular dynamics (MD) simulations revealed that in both copolymers, there was minimal interaction between the gases (CO₂ and N₂) and the hydrophobic PTFEMA segments, while CO₂ showed strong affinity for the hydrophilic POEM segments. The block and random copolymers demonstrated similar CO₂ permeance, which can be attributed to their comparable CO₂ diffusivity and solubility. However, the block copolymer exhibited significantly lower N₂ permeance than the random copolymer, resulting in nearly quadruple the CO₂/N₂ selectivity. This increase in selectivity was supported by the lower N₂ mean squared displacement (indicating reduced diffusivity) observed in the block copolymer. The PTF block copolymer outperformed the commercial Pebax block copolymer, achieving CO₂ capture efficiencies that surpass industrial standards for CO₂ separation and capture. This positions the single-matrix PTF block copolymer as a promising alternative to mixed-matrix membranes for practical applications in gas separation technologies.

Integrating Metal–Organic Frameworks and Polyamide 12 for Advanced Hydrogen Storage Through Powder Bed Fusion

This paper introduces a pioneering approach that combines ex situ synthesis with advanced manufacturing to develop ZIF-67-PA12 Nylon composites with mixed-matrix membranes (MMMs), with the goal of enhancing hydrogen storage systems. One method involves producing MOF-PA12 composite powders through an in situ process, which is then commonly used as a base powder for powder bed fusion (PBF) to fabricate various structures. However, developing the in situ MOF-PA12 matrix presents challenges, including limited spreadability and processability at higher MOF contents, as well as reduced porosity due to pore blockage by polymers, ultimately diminishing hydrogen storage capacity. To overcome these issues, PBF is employed to form PA12 powder into films, followed by the ex situ direct synthesis of ZIF-67 onto these substrates at loadings exceeding those typically used in conventional MMM composites. In this study, ZIF-67 mass loadings ranging from 2 to 30 wt.% were synthesized on both PA12 powder and printed film substrates, with loadings on printed PA12 films extended up to 60 wt.%. ZIF-67-PA12-60(f) demonstrated a hydrogen capacity of 0.56 wt.% and achieved 1.53 wt.% for ZIF-67-PA12-30(p); in comparison, PA12 exhibited a capacity of 0.38 wt.%. This was undertaken to explore a range of ZIF-67 Metal–organic frameworks (MOFs) to assess their impact on the properties of the composite, particularly for hydrogen storage applications. Our results demonstrate that ex situ-synthesized ZIF-67-PA12 composite MMMs, which can be used as a final product for direct application and do not require the use of in situ pre-synthesized powder for the PBF process, not only retain significant hydrogen storage capacities, but also offer advantages in terms of repeatability, cost-efficiency, and ease of production. These findings highlight the potential of this innovative composite material as a practical and efficient solution for hydrogen storage, paving the way for advancements in energy storage technologies.

A Zn‐MOF With Its Mixed‐Matrix Membranes for Convenient and Efficient Visualization Detection of 3‐Nitrotyrosine Biomarker in Aqueous Media and Practical Application in Serum

ABSTRACTInstant and accurate detection of 3‐nitrotyrosine (3‐NT) biomarker is an important but challenging task in clinical diagnosis, treatment, and monitoring of diseases. Herein, this work reported a Zn (II)–based metal–organic framework (MOF) {[Zn2(BDPT)(DIMB)]}n, denoted as Zn‐BDPT, synthesized by solvothermal method using bis(3,5‐dicarboxyphenyl)terephthalamide (H4BDPT) and 1,4‐di(1H‐imidazol‐1‐yl)butane (DIMB). Neighboring [Zn (COO)2] clusters were connected by BDPT4− units and DIMB to form a (2,4,4)‐connected three‐dimensional (3D) architecture. X‐ray powder diffraction (PXRD) and thermogravimetric (TGA) experiments indicated that Zn‐BDPT had good purity and stability. Zn‐BDPT could selectively and rapidly recognize 3‐NT in an aqueous environment. For rapid economic detection of 3‐NT in actual samples, mixed‐matrix membranes (MMMs) based on Zn‐BDPT were successfully prepared and named Zn‐BDPT@PMMA. The addition of 3‐NT under the UV lamp displayed an evident visible fluorescence quenching effect. Quantitative titration analysis of Zn‐BDPT@PMMA in real serum sample obtained the Ksv value of 1.13 × 104 M−1 and a limit of detection (LOD) of 0.17 μM. This report demonstrated that MOF‐based MMMs could be used as ideal candidate for luminescent probe in actual application.

Construction of Asymmetric Filler Density Mixed-Matrix MOF Membranes via Liquid-Phase Ion Activation for Advanced Oxidation Processes.

Mixed-matrix membrane (MMM) reactors incorporating metal-organic framework (MOF) fillers have significant applications in fields such as separation, catalysis, and chiral resolution. However, the traditional method of directly mixing MOF fillers with polymers results in a symmetric structure where most of the MOF fillers are uniformly distributed across the membrane reactor's cross-section. During usage, this leads to a pronounced trade-off between flux and efficiency and the waste of the MOF, as the rich pore characteristics and active sites of MOFs are not fully utilized. In this study, we propose a liquid-phase ion activation strategy that enables the in situ formation of a uniform and densely packed MOF shell layer on the membrane surface during the phase inversion process of MMM fabrication. This asymmetric density distribution of the MOF-based MMM reactor selectively induces the generation of considerable nonradical 1O2 in the peroxomonosulfate (PMS) system, demonstrating superior catalytic degradation performance against antibiotics like TC and dye molecules (with a flux of 1880 L m-2 h-1 and a Kapp value of 648 min-1), as well as outstanding cycling stability and environmental tolerance. This discovery sheds light on the design and engineering of composite membrane materials and applications for advanced oxidation processes in water purification.

Advancements in Mixed-Matrix Membranes for Various Separation Applications: State of the Art and Future Prospects

Integrating nanomaterials into membranes has revolutionized selective transport processes, offering enhanced properties and functionalities. Mixed-matrix membranes (MMMs) are nanocomposite membranes (NCMs) that incorporate inorganic nanoparticles (NPs) into organic polymeric matrices, augmenting mechanical strength, thermal stability, separation performance, and antifouling characteristics. Various synthesis methods, like phase inversion, layer-by-layer assembly, electrospinning, and surface modification, enable the production of tailored MMMs. A trade-off exists between selectivity and flux in pristine polymer membranes or plain inorganic ceramic/zeolite membranes. In contrast, in MMMs, NPs exert a profound influence on membrane performance, enhancing both permeability and selectivity simultaneously, besides exhibiting profound antibacterial efficacy. Membranes reported in this work find application in diverse separation processes, notably in niche membrane-based applications, by addressing challenges such as membrane fouling and degradation, low flux, and selectivity, besides poor rejection properties. This review comprehensively surveys recent advances in nanoparticle-integrated polymeric membranes across various fields of water purification, heavy metal removal, dye degradation, gaseous separation, pervaporation (PV), fuel cells (FC), and desalination. Efforts have been made to underscore the role of nanomaterials in advancing environmental remediation efforts and addressing drinking water quality concerns through interesting case studies reported in the literature.