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The drive to decarbonize chemical processes necessitates exploring low-energy solutions for separating complex liquid mixtures ubiquitous in food, pharmaceuticals, petrochemical, and synthetic fuel production industries. This report comprehensively investigates conceptualizing and implementing two novel organic solvent separation processes: Organic Solvent Forward Osmosis (OSFO) and Organic Solvent Pressure Assisted Osmosis (OSPAO). The intrinsic molecular specificity of ultramicroporous carbon molecular sieve (CMS) membranes allowed the unprecedented separation of a complex mixture of short-chain alcohols (e.g. , methyl alcohol, ethyl alcohol, and isopropyl alcohol) at room temperature. A new hybridized membrane-based separation methodology, OSPAO, that combines the elements of organic solvent nanofiltration (OSN) and OSFO is introduced. CMS-based OSPAO demonstrated a marked enhancement in the flux of organic species permeate, considerably improving separation efficiencies. The separation modalities presented in this report underscore the essential role of osmosis in the differentiation of organic solvents, thereby contributing valuable insights to osmosis-based separation technologies. [Display omitted] • This study investigates OSFO and OSPAO separations of ternary alcohol mixtures using a CMS/alumina composite hollow fiber. • Optimizing the CMS structure through varying pyrolysis temperature yields outstanding size selectivity. • The hierarchical CMS pore structure enables mass transport combining solution-diffusion and pore flow in OSPAO mode. • OSPAO separation enhances the transport rate of alcohols while preserving molecular selectivity. [ABSTRACT FROM AUTHOR]

For antibiotics, the purification and separation in the synthesis process, as well as enrichment and recycling in the utilization process, has a profound impact on human health and environmental issues, which pose an unignorable challenge for selective molecular sieving of separation technology. Herein, we offered a convenient high-accuracy separation membrane construction by using three dimensional rigid triptycenes as building-blocks to fabricate porous triptycene networks polyarylate nanofilms (PTN-NFs) by interfacial polymerization. With permanent porous structure and excellent stability, the PTN-NF membrane exhibited remarkable separation precision around 90 g mol−1 scale for several mixture separation and significant selectivity as high as 39.3 for piperacillin/6-aminopenicillanic acid (6-APA) separation. The contorted rigid triptycene monomer 2,6,14-trihydroxyltriptycene (THT) was employed by one-step interfacial polymerization to fabricate a porous triptycene network (PTN) thin film membrane (PTN–NF– 1) for the first time. The PTN–NF– 1 manifested the high selective accuracy of ∼90 g mol−1, from which realized the precise separation in several mixed systems, including antibiotics separation of 6-APA/piperacillin, for which the selectivity was calculated to be 39.3. [Display omitted] • A new porous triptycene networks nanofilm was fabricated for the first time. • The membrane exhibited remarkable separation precision around 90 g mol−1 scale. • The membrane realized accurate molecular sieving in several mixtures. • The membrane reached 39.3 significant selectivity for piperacillin/6-APA separation. [ABSTRACT FROM AUTHOR]

Coupling photocatalysis with membrane separation technology becomes one pioneering method to solve the membrane fouling. In this study, Ag@SnS photocatalyst was synthesized and blended with polyvinylidene fluoride (PVDF) to fabricate Ag@SnS/PVDF composite membranes via non-solvent induce phase separation (NIPS) method. The results show that with the addition of Ag@SnS, water flux of Ag@SnS/PVDF hybrid membranes increases due to the enhanced membrane hydrophilicity and increased porosity. The optimal hybrid membrane (MAS-2) exhibits the rejection rate of 97.0 % and 95.4 % for BSA and HA accompanied with a water permeance of 578.5 L m−2 h−1 bar−1. Moreover, MAS-2 membrane reveals excellent self-cleaning ability by photodegradation of HA on membrane surface, and its flux recovery rate (FRR) can achieve 91.7 % after UV irradiation and 95.8 % after 3 h natural sunlight irradiation via photocatalysis regeneration. The heterostructure of Ag@SnS can assist separation of photoinduced electrons and holes by transferring photoinduced electrons to Ag nanoparticles with enhanced photocatalytic activity. After three cycles, the FRR can still reach around 90.0 %, revealing its outstanding cleaning ability. Therefore, the Ag@SnS/PVDF membranes have a foreseeable potential in the field of water treatment due to its high flux performance, self-cleaning ability via photocatalysis process. [Display omitted] • Ag@SnS/PVDF photocatalytic membranes were revealed for the first time. • The membrane shows a PWP of 578.5 L m−2 h−1 bar−1 and BSA rejection of 97.0 %. • The fouled Ag@SnS/PVDF membranes can be regenerated via UV or sunlight irradiation. • Heterostructure of Ag@SnS enhanced the photocatalytic activity of the membranes. [ABSTRACT FROM AUTHOR]

The separation of oil from oily water is a critical endeavor owing to the escalating global oil pollution. Membrane separation technology has gained widespread adoption for oily water treatment. Inspired by the vertical segregation phenomenon in drying multi-component suspensions, this study proposed an evaporation-induced stratification coupled with sacrificial template method to prepare superhydrophobic polychlorotrifluoroethylene (PCTFE) membrane for fast gravity-driven oil/water separation. The precursor of PCTFE microporous membranes, PCTFE/fluoroelastomer/hydrophobic silica nanoparticles (PCTFE/FR/SiO 2) composite films, were fabricated via a solvent-assisted method. Induced by solvent evaporation, the pre-fabricated composite films exhibited a stratified structure, where SiO 2 nanoparticles enriched near the top surfaces, making it easily tailor the surficial wettability. For the matrix, PCTFE-rich domains and FR-rich domains intersected, forming a bicontinuous structure. After sacrificing FR, PCTFE porous membranes were obtained. Meanwhile, the PCTFE-based porous skeletons combining with surface enriched SiO 2 nanoparticles constructed a multi-level roughness, thus achieving superhydrophobicity. The optimized membrane possessed an average pore size of ∼1.84 μm, a porosity of ∼60 %, and a WCA above 155°, owning excellent self-cleaning properties and efficient oil/water separation ability. The membrane exhibited remarkable capability in various oil/water mixtures, including emulsified water-in-oil. The separation flux and oil recovery purity for water-in-dichloromethane emulsion were up to 2843 ± 84 L/(m2·h) and 99.95 wt%, respectively. Furthermore, though being immersed into various organic solvents for 7 days or experiencing 15 separation cycles, the performances of the membranes hardly changed. Accordingly, this work provides a practical approach for tailoring surficial wettability and fabricating PCTFE-based membranes suitable for oil/water separation fields. [Display omitted] • Novel strategy to fabricate superhydrophobic PCTFE membrane. • An evaporation-induced stratification coupled with sacrificial template. • Evaporation-induced stratification was adopted to tailor surface wettability. • Remarkable capability in segregating various oil/water mixtures and emulsion. • Excellent self-cleaning property, reusability, and organic solvent resistance. [ABSTRACT FROM AUTHOR]

Chitosan, as the second most abundant biopolymer on earth, is constantly increasing attention from different fileds such as biomedicals, food, energy, and the environment. However, its application in membrane technology such as pervaporation is lacking of an effective membrane manufacture strategy to improve its separation efficiency. Herein, we use a chitosan-based membrane subjected to neutralization and crosslinking procedures in contrasting solvents—specifically, water and ethanol—to explore the impact of polymer-solvent interactions on the effective nanogaps between polymer nanofibers. Under identical conditions, the procedures conducted in water yield hydrated membranes, while those in ethanol resulted in anhydrous membranes. In hydrated membranes, strong hydrogen bonds formed between water and amine groups block nanogaps amongst polymer nanofibers, significantly impeding molecular transport. Conversely, the absence of such strong hydrogen bonds in anhydrous membrane avoided this effect. This study highlights the potential of controlling the transport of organic molecules by tuning the nanogaps within the membrane matrix. This was achieved through a novel strategy involving washing the chitosan-based membranes with pure ethanol to remove free acids, followed by direct crosslinking in a glutaraldehyde ethanol solution. This strategy was able to double the membrane selectivity despite a 25 % reduction in methanol permeance. [Display omitted] • A fabrication strategy boosts organic mixture separation with CS-based membranes. • CS-solvent effects on the CS nanogap in the membrane fabrication are studied. • Water-produced membranes show strong hydrogen bonds, slowing molecular transport. • Ethanol-produced membranes lack strong hydrogen bonds, avoiding the effect. [ABSTRACT FROM AUTHOR]

Due to the growing demand for lithium in the new energy industry, significant attention has been focused on developing lithium extraction technologies from salt-lake brine. However, the high Mg/Li ratio in salt-lake brine presents challenges for membrane separation technology. If a membrane can allow Mg2+ and water molecules to pass through while retaining Li+, the retained brine will have concentrated Li+ with a reduced Mg/Li ratio, creating the facilitation of further lithium extraction. In this study, we discovered through non-equilibrium molecular dynamics simulations that strongly hydrophilic covalent organic frameworks membranes capture Li+ in their pores, preventing additional Li+ from entering the nanopores. Meanwhile, Mg2+ can freely penetrate these nanopores along with water molecules. This adsorption of Li+ and the free permeation of Mg2+ with water molecules result in the effective separation of Li+ and Mg2+. Consequently, the retained brine becomes lithium-rich with reduced Mg/Li ratio. The findings of this work provide valuable guidance for designing nanofiltration membranes for extracting lithium from salt lakes with high Mg/Li ratio. [Display omitted] • The adjustment of membrane hydrophilicity influences the Mg/Li selectivity. • Enhanced membrane hydrophilicity promotes Li + retention, rather than Mg2+. • Strong hydrophilicity induces the adsorption of Li + onto the pore walls. • High concentration of Li + inside membranes hinders further entrance of Li+. • The penetration of Mg2+ is not influenced due to the large pore size of TpPa. [ABSTRACT FROM AUTHOR]

Traditional membrane separation technology for pharmaceutical tailwater purification has certain limitations, including inefficient removal of residual drugs and serious membrane fouling. This report describes a novel electro-Fenton membrane that was fabricated by coating an iron single-atom porous carbon layer (Fe-SA@PC/CM) and used to promote the in situ degradation of the antibiotic, amoxicillin, in pharmaceutical tailwater during electro-Fenton membrane filtration (EFMF). The Fe-SA@PC/CM membrane exhibited excellent electrocatalytic activity and conductivity for the oxygen reduction reaction. The designed flow-through mode remarkably outperformed the flow-by and conventional batch modes, with the corresponding mass transfer rate constant (k m) reaching 0.0044 cm/s. Active species identification and COMSOL simulations demonstrated that the enhanced convective diffusion of H 2 O 2 was crucial for supporting continuous •OH production. The Fe-SA@PC/CM membrane exhibited favorable durability and self-cleaning properties and could feasibly purify pharmaceutical tailwater. This study provides new insights regarding approaches to enhance EF oxidation via the convection-diffusion of oxygenated reactants for synergistic wastewater purification and membrane fouling mitigation. [Display omitted] • Electron transfer ability enhances O 2 reduction on the surface of Fe-SA@PC/CM. • High mass transfer efficiency of Fe-SA@PC/CM accelerates amoxicillin removal. • Convective diffusion of oxidants is essential for electro-Fenton membrane filtration. • Fe-SA@PC/CM showed favorable durability and feasibility in practical application. • In situ self-cleaning of Fe-SA@PC/CM effectively mitigates membrane fouling. [ABSTRACT FROM AUTHOR]

Advanced CO 2 separation technology is one of the key technologies for reducing carbon emissions and can make significant contributions to reducing the negative impact of the greenhouse effect on human survival. Membrane separation technology is regarded as a new generation of carbon capture technology because of its great potential to reduce carbon capture energy consumption and improve net carbon capture efficiency. Mixed matrix membranes (MMMs) can break through the performance limit of traditional polymer membranes, but the influence of bridging agents for post-modifying nanofillers on membrane structure and properties needs further systematic investigation. In this work, four types of ligands were selected for synthesizing polymer-modified nanofillers and then incorporated into poly (vinylamine) (PVAm) to prepare MMMs. The comparative analysis results indicate that bridging ligands with superior flexibility are conducive to enhancing the gas permeability within the pores by diminishing the compactness of the polymer shell. The constructed phase interface transition area with uniformly enhanced mechanical strength demonstrates the improved interface compatibility between the matrix and nanofillers bridged via the flexible ligand. Techno-economic evaluation verifies the industrial application potential of the optimal MMMs targeting CO 2 capture from post-combustion gas. Diagram of Nanofillers Structure Post-modified Using Polymer Homologous to the Matrix via Different Bridging Ligands. [Display omitted] • The properties of the polymer shell were regulated by bridging ligands with different flexibility. • Post-modification of nanofillers by homologous polymer generated excellent interfacial compatibility. • Ligands with strong flexibility stretched outer polymer to promote nanofillers' gas permselectivity. • The Maxwell model was conducted to verify the superiority of UIO- DEB -PVAm nanofillers. [ABSTRACT FROM AUTHOR]

Successful pre-combustion CO 2 capture from synthetic gas for H 2 production requires effective membrane separation technology. While polymer-based membrane materials offer promising industrial scalability, they generally lack a sufficiently high H 2 /CO 2 selectivity to make this process energy-efficient. In this work, we have designed a scalable dual-polymer blend membrane consisting of sulfonated polyphenylsulfone (sPPSU) and polybenzimidazole (PBI), and then being infiltrated with amine-rich poly(ethyleneimine) (PEI) molecules as effective CO 2 retardants to substantially elevate the H 2 /CO 2 selectivity. PEI molecules were infiltrated into the dual-polymer matrix via solution-treatment to crosslink the polymer network and retard CO 2 transport using its amine-rich nature. The PEI infiltration dramatically increased the H 2 /CO 2 selectivity of the dual-polymer matrix from 4.6 to up to 59.3 while maintaining a minimum H 2 permeability of 2.49 Barrer at a low temperature of 35 °C, which not only surpasses the Robeson upper bound but also places the newly developed membrane among the best-performing polymer-based membranes. More importantly, the solution infiltration of PEI incurs no phase segregation, maintaining the polymer mechanical robustness, which is crucial for industrial scaling. This study offers promising opportunities to develop three-polymer membrane systems for H 2 /CO 2 separation using synergistic polymer blends and CO 2 -retarding molecules. [Display omitted] • A three-polymer membrane system was developed for H 2 /CO 2 separation at ambient temperature. • Synergistic scalable dual-polymer blends and CO 2 -retarding molecules were employed for better H 2 /CO 2 separation. • No phase segregation for the membrane system, it had mechanical robustness for industrial scaling. • The sPPSU-PBI-PEI membranes enabled H 2 /CO 2 separation performance surpassing the upper bound. [ABSTRACT FROM AUTHOR]

Emerging nanofiltration (NF) separation technology for precision ionic/molecular separation at the nanoscale, which has the advantages of energy conservation, excellent separation and a small footprint, is promising for obtaining sustainable water resources via efficient water treatment and recycling. However, traditional NF membranes are restricted to applications at approximately room temperature because of the sharp deterioration in stability induced by the fragility of the nanopore structure at higher temperatures. Herein, we synthesized an unparalleled nanofiltration (NF) membrane with superior thermal stability up to 90 °C and finely tailored nanopores with 0.3–1.1 nm, via de novo carbon skeleton-mediated polymerization (CSMP). Molecular thermodynamics simulations and experiments demonstrated that C–C skeletons can manipulate the stability of the intrinsic structure and intermolecular gap size, contributing to exceptionally thermostable and well-tailored nanopores. The synthesized membrane exhibited excellent long-term water permeance and high rejection of (sub)nanoscale contaminant molecules at high temperatures, which is far superior to the performance of currently available NF membranes. [Display omitted] • The designed VTEs-VP-GMA reactive monomer is successfully synthesized. • The thermostable and tailored nanofiltration membrane is successfully synthesized. • The rigidity of C–C skeletons from VP improves the stability of nanopores. • VP tailors sizes of nanopores through C–C skeleton bridging between reactive sites. • The nanofiltration membrane exhibits excellent operational and thermal stability. [ABSTRACT FROM AUTHOR]

Achieving highly selective separation of organic mixtures is crucial to modern fine chemicals and pharmaceutical industries. The membrane-based organic solvent reverse osmosis (OSRO) technology is expected to break through this barrier. The key to achieving the separation of organic mixed liquids is to design the OSRO membrane as needed based on the physical and chemical properties of the target separation solvent. However, this poses a huge challenge to traditional OSRO membranes. In this work, we report composite polyamide (PA) OSRO membranes with ultrahigh polar/non-polar organic mixture selectivity. The surface polarity of the composite PA membrane is increased by coating a layer of Fe3+/tannic acid (Fe3+/TA) layer on the surface of the PA membrane. The enhanced surface polarity increases the interaction difference between polar and non-polar solvents and the membrane. And a polarization layer is formed on the membrane surface, which weakens the concentration polarization effect on the membrane surface. Under high-concentration feed liquid (the mass ratio of methanol/hexane is 7:3), the separation factor of the prepared membrane reaches 218, which is the highest value of all OSRO membranes reported so far. For the first time, we establish a partial flux analysis for the OSRO process. This analysis unravels the pressure, concentration dependence, and sensitivity of separation performance. It provides novel insights into the design of high-performance OSRO membranes. [Display omitted] • High-performance OSRO PA membrane prepared by Fe3+/TA surface modification. • Fe3+/TA coating enhances the surface polarity of PA membrane. • Enhanced surface polarity affects membrane-solvent interactions. • PA-Fe3+/TA membranes show ultrahigh separation factor for methanol/hexane mixture. • Established partial flux analysis to gain in-depth understanding of OSRO process. [ABSTRACT FROM AUTHOR]

The development of analytical models for predicting the transport properties of membranes in the separation of multicomponent mixtures is highly relevant because (1) measurements of permeability and sorption of gas mixtures in membrane materials are laborious and time-consuming, and (2) estimation of transport properties based on pure gas measurements is desirable, however, rather unreliable and can lead to serious errors. In this paper, within the framework of the well-known frictional-coefficient formalism, we present nonlinear equations for the fluxes of gas mixture components through the membrane, which take into account the diffusional coupling of the fluxes compared to independent gas transport. As a result, an analytical equation for the mixed-gas selectivity was obtained. This equation has an implicit form, which is not quite convenient for practical application, since it has to be solved numerically. A simple explicit expression for mixed gas selectivity was derived using the so-called linear transport model, which is a linearized version of the original nonlinear flux equations. It is important to emphasize that a comparison of the linear model with the formally more rigorous nonlinear model showed only minor quantitative differences. The input parameters for the model are the single gas transport parameters. Testing the linear model using experimental data for the separation of hydrocarbons (n -butane/methane, n -butane/ i -butane, propylene/propane) revealed an acceptable fit. A comparison of the model with recent experimental data on the separation of CO 2 -containing mixtures using microporous polymers is also presented. It is found that the calculated CO 2 /N 2 mixed gas selectivity is in good agreement with the experimental data, while only a semi-quantitative agreement is observed for the CO 2 /CH 4 separation. Besides, it is shown that the model developed for binary gas separation can be extended to ternary gas mixtures. [Display omitted] • Analytical model of binary gas permeation through membrane. • Explicit expression for mixed-gas selectivity of membrane. • Input parameters are single gas transport parameters. • Model extension to ternary gas permeation. [ABSTRACT FROM AUTHOR]

Conventional techniques for the removal of silicone oils from small siloxane molecules (either cyclic species, such as D4 or linear siloxanes, known as L2-L6) include stripping and adsorption. Membrane separations could serve as low-energy alternatives or complements to these industrial separation techniques to reduce the overall process energy demand since they do not involve a phase change. This paper presents polymeric membranes as materials for purifying D4 (octamethylcyclotetrasiloxane) rich feed of 90 % D4 from a silicone fluid mixture. The transport properties (diffusion, sorption, and permeation) are studied experimentally to understand the driving force and mechanism for the separation related to the properties of the penetrant molecules, such as molecular size. These parameters are utilized in the solution-diffusion model to predict the permeation rates and separation performance of PDMS membranes for the siloxane-silicone fluid mixtures that are rich in the small siloxane. The results presented here suggest that PDMS membranes may serve as an industrially scalable low-cost alternative to small siloxane purification. [Display omitted] • OSRO separation of cyclic siloxane/silicone oil mixture studied for the first time. • Siloxanes and silicone oil sorption in PDMS obeys near-Fickian transport. • Transport of siloxanes follows the solution-diffusion model. • Separation of the siloxane-oil mixture is mostly driven by sorptive selectivity. • PDMS membrane is feasible for siloxane cleansing to achieve commercial grade of D4. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3) produced by Haber-Bosch process is separated through the condensation process, which needs a large amount of energy consumption. Membrane separation technology is compelling for achieving energy-saving and efficient NH 3 separation. Therefore, 3-(trihydroxysilyl)-1-propanesulfonic acid (TPS) was applied, for the first time, to fabricate sulfonic silica-based membranes and evaluated for NH 3 selective permeation. The amorphous siloxane network can be formed by simple condensation of silanol (Si–OH) under sulfonic acid (-SO 3 H) self-catalysis, as confirmed by the results of Fourier transform infrared spectroscopy and X-Ray diffractometry. Moreover, TPS xerogel powders dried from TPS sols showed excellent thermal stability and dense structure via thermogravimetric and N 2 adsorption analyses. Importantly, an intensive NH 3 adsorption amount of ∼3.0 mmol g−1 for TPS xerogels from NH 3 adsorption and temperature-programmed desorption was twice higher than the reported oxidized (3-mercaptopropyl)trimethoxysilane xerogels (∼1.41 mmol g−1), which was ascribed to the inherently stronger proton-acidic -SO 3 H groups in TPS. Finally, TPS membranes prepared using TPS solutions diluted with ethanol expressed superior NH 3 -selective permeation based on favorable molecular sieving and NH 3 adsorption-diffusion via single and binary gas permeation, especially remarkable NH 3 permeance of ∼2.6 × 10−7 mol m−2 s−1 Pa−1 and excellent NH 3 /N 2 selectivity of 266 at 300 °C. [Display omitted] • Siloxane was obtained from condensation of Si–OH by self-catalysis of -SO 3 H groups. • TPS gel has high NH 3 adsorption amount of 3.0 mmol g−1 due to inherent -SO 3 H groups. • TPS membrane was simply fabricated via coating TPS solutions on intermediate layer. • TPS membrane can be used for a wide range of 50–300 °C with an excellent performance. [ABSTRACT FROM AUTHOR]

The integration of membrane separation and electrospinning technologies has significantly advanced oil-water separation processes. However, enhancing the mechanical robustness, corrosion resistance, and durability of oil-water separation membranes remains a challenge. In this paper, we utilized the electrospinning technique to fabricate a micro-nanostructured nanofibrous (NFs) membrane by blending benzophenone monomer (BPAF-an) with thermoplastic polyurethane elastomer (TPU). By optimizing the solid content, the mass ratio of compounds to polymers, and the solvent composition in the spinning precursor solution, we determined the optimal electrospinning parameters for fabricating the TPU/BPAF-an NFs membrane. The incorporation of BPAF-an, known for its low surface energy, significantly enhanced the hydrophobicity of the nanofiber membrane. The TPU/BPAF-an NFs membrane demonstrated excellent mechanical properties, exhibiting a tensile strength of 7.38 MPa and an elongation at break of 292 %. The membrane had good hydrophobicity and its water contact Angle is up to 145.2°. It also displayed exceptional separation efficiency, exceeding 99 % for oil-in-water emulsions and various oil-water mixtures. Even in harsh environments such as strong acids, alkalis and salts, they have prominent hydrophobicity, lipophilicity and chemical stability. In addition, the membrane maintained a high flux rate of 1995.37 L m−2 h−1 and a separation efficiency of 96 % even after 100 cycles of oil-water separation. Consequently, the TPU/BPAF-an NFs membrane, with its superior mechanical properties and cycle stability, holds substantial promise for application in oil-water separation. [Display omitted] • Benzoxazine/elastic polyurethane nanofibrous membrane fabricated via electrospinning. • The membranes demonstrate excellent mechanical properties. • The membrane exhibits high efficiency in the separation of oil-water and emulsions. • The membranes have good corrosion resistance and durability. [ABSTRACT FROM AUTHOR]

Gas transport properties of two sets of polynorbornenes bearing carbocyclic substituents of different nature (cyclohexyl, norbornyl, phenyl groups, and framed oligocyclic moieties) were systematically studied. The influence of side chain carbocyclic substituents on gas permeability and separation selectivity for CO 2 -containing gas pairs and gaseous hydrocarbons was evaluated. It was found that the presence of carbocyclic moieties in side chains of polynorbornenes promotes the increase in gas permeability similarly to that of SiMe 3 groups, with this effect being enhanced by the increase in the number of cycles in the substituents. As a result, P (CO 2) of the metathesis polymer with pentacene-based substituents is equal to 1200 Barrer. Studied polynorbornenes with carbocyclic substituents displayed promising gas separation selectivities: CO 2 /N 2 separation selectivity up to 41 (above the 2008 upper bound in the Robeson diagram) and solubility-controlled hydrocarbon separation selectivity up to 16 for the n -butane/methane gas pair. For the polymer with pentacene-based substituents, the separation of the mixture of hydrocarbons and aging were studied. The studies revealed that the mixed gas C 4 /C 1 separation selectivity of this polymer reaches 4, and a two-time reduction of permeability occurs in 8.5 months. Therefore, the incorporation of carbocyclic groups in the side chains of polynorbornenes can be considered as an efficient strategy for the design of polymeric gas separation membrane materials. [Display omitted] • Structure-property study of polynorbornenes with carbocycles in side chains. • Carbocyclic moieties improve both CO 2 permeability and CO 2 /gas selectivity. • Polymeric membranes for CO 2 /N 2 and hydrocarbons separation. • Framed carbocyclic structures are Si-free alternatives to SiMe 3 substituents. • The characteristics of AP-NBNBa for CO 2 /N 2 are above 2008 Robeson upper bound. [ABSTRACT FROM AUTHOR]

Traditional thin film composite polyamide nanofiltration (NF) membranes are difficult to simultaneously achieve high rejection for salts that are divalent anionic and cationic, and their separation selectivity for mono-/di-valent salt separation is usually poor. Herein, novel polyesteramide NF membranes were developed by interfacial polymerization on modified poly(vinylidene fluoride) (PVDF) substrates containing tannic acid (TA) self-assembled coating (TC@PVDF). TC@PVDF substrates were firstly fabricated via non-solvent induced phase separation technology using amphiphilic hyperbranched poly(methyl methacrylate- co -N-methylacrylamide) (HPMH) copolymers as in situ modifiers and TA aqueous solution as coagulation bath. The self-assembly behavior between TA and HPMH results in the increase of substrate surface hydrophilicity, electronegativity and pore size, which would facilitate the storage and uniform distribution of aqueous monomer piperazine on the substrate surface. For these reasons, TA coating interlayered NF (TCi-NF) membrane exhibits a thick polyesteramide layer with crisscrossing ridge surface morphology, a low molecular weight and a small pore size. The TCi-NF membrane not only demonstrates high rejection toward Na 2 SO 4 (99.3 %) and MgCl 2 (95.7 %), but also displays exceptional separation selectivity for both mono-/di-valent anions [α(Cl−/SO 4 2−) = 49] and mono-/di-valent cations [α(Na+/Mg2+) = 52]. Since the surface charge property of TCi-NF membrane is close to weak negativity, electrostatic effect between charged ions and membrane surface would be weakened, so the separation mechanism mainly depends on the size exclusion effect. Specifically, the TCi-NF membrane displays stable long-term separation performance and high salt concentration resistance. Therefore, this research provides a new preparation strategy for improving the precise desalination performance of thin film composite NF membranes. [Display omitted] • Tannic acid (TA) aqueous solution as coagulation bath adjusts structure of substrates by surface self-assembly. • TA coating interlayer (TCi) plays multiple roles in interfacial polymerization process. • Weakly negative TCi-NF membrane with low MWCO and small pore size. • Outstanding separation selectivity for both Cl−/SO 4 2− and Na+/Mg2+. • Excellent long-term stability and high salt concentration resistance. [ABSTRACT FROM AUTHOR]

The sulfur removal from crude oil is important for economic, energetic, and environmental reasons. Membranes are competitive for a variety of industrial separations and could be integrated in oil fractionation process. The key challenge lies in designing materials that are easily processable for membrane production while delivering high performance under the demanding conditions of industrial operation for the separation of intricate mixtures. We report the synthesis of polytriazole membranes with chemically stable hydrophilic and hydrophobic segments. These membranes were evaluated for the fractionation of crude oil, demonstrating the capability to separate lighter oil fractions, and remove asphaltene. Simultaneously, they exhibit an impressive capability to eliminate up to 50% of the sulfur compounds. Their superior performance has the potential to expedite the shift toward a more sustainable petrochemical industry. [Display omitted] • Copolytriazole with hydrophobic/hydrophylic units for complex separations. • Copolytriazole membranes for asphaltine separation. • Membranes able to eliminate up to 50% of the sulfur compounds. • Fractionation of crude oil. [ABSTRACT FROM AUTHOR]

The increasing release of oily wastewater from both household and industrial activities has led to a significant environmental challenge. Among the various methods for treating oil-water mixtures, membranes with specialized wettability characteristics have emerged as one of the most effective and cost-efficient approaches. In this field, reducing the thickness of membranes is a key strategy to lessen resistance to mass transfer. This paper describes the creation of a super-hydrophobic, submicron-thin (945 nm) and even transparent (79.99% relative transparency at 600 nm wavelength) composite membrane for oil/water separation. This was achieved by depositing polydivinylbenzene (PDVB) onto ∼170 nm ultrathin freestanding polyethylene (PE) membranes to form hierarchical rough textures. Based on the super-hydrophobicity and high roughness, PE/PDVB composite membrane is enabled to separate oil from water in both mixtures and emulsions of immiscible oil/water. Moreover, PE/PDVB demonstrated a separation efficiency exceeding 99.91% for various water-in-oil emulsions. Impressively, this efficiency could be sustained above 99.87% even after 30 cycles of separation involving surfactant-stabilized isooctane/water emulsions. This performance robustness persisted against various chemical environments such as acidic, alkaline, and saline conditions over prolonged periods. To our knowledge, PE/PDVB is currently the thinnest oil/water purification membrane available, combining both an active layer and support. This work also highlights the practicality of using an ultra-thin support layer for efficient oil/water separation. This work may be at use for membrane scientists who are developing ultra-thin membrane materials and processes for future applications. TOC graphic: The first submicron ultrathin oil/water purification membrane. [Display omitted] • The whole oil/water purification membrane has been thinned down less than 1 micron-thin, for the first time. • High efficiencies of separating immiscible mixtures and emulsions were both reported. • The cyclic stability, chemical resistance and mechanical integrity have been verified. [ABSTRACT FROM AUTHOR]

Membrane-based pervaporation (PV) is an energy-efficient separation technology for liquid molecular mixtures, which is an increasingly important function in chemical industries. This work accomplished the first synthesis of high-performance FAU (NaX type) zeolite membranes on α-alumina tubular supports via the secondary growth method using 50 nm nanoseeds. The effects that the synthesis parameters exerted on the crystal structures, morphologies, and PV performance of FAU membranes were systematically investigated. The nanosized seeds showed high levels of activity that promoted the rapid growth of the zeolite layer. In addition, either extending the crystallization time or raising the temperature readily caused trans -crystallization to form NaP impurity zeolites, which decreased the membrane flux and separation factor. When synthesis conditions were optimized, a high-quality and pure-phase FAU membrane was obtained and tested for the permeation of single gases and for the PV dehydration of various organic solvents (methanol, ethanol, n-propanol, iso-propanol, and tert-butanol). The relationships between the single-gas permeance, PV permeance, and polarity index were investigated using a similar size range of permeate molecules (0.289–0.5061 nm). The results show that gas permeance exhibits Knudsen selectivity. The PV permeance, however, correlated well with the polarity index of the permeate, which indicates that PV dehydration through the FAU membrane is controlled by an adsorption-diffusion mechanism. Moreover, the correlation provides a new tool for predicting PV performance. Compared with studies using FAU membranes, the as-synthesized FAU membrane features good reproducibility, excellent stability, and high PV performance, which suggests the great potential of FAU membranes for use in industrial organic solvent dehydration. Schematic illustrations of the hydrothermal synthesis of FAU membranes derived from nanoseeds for pervaporation dehydration, as well as a PV performance prediction via the polarity index. [Display omitted] • Synthesis parameters are optimized to form a high-performance FAU membrane. • Nanoseeds are highly active and promote the growth of the zeolite layer. • PV dehydration is controlled by the adsorption-diffusion mechanism. • PV performance correlated well with the polarity index of solvents. • Polarity index is used to predict PV performance. [ABSTRACT FROM AUTHOR]

Nanofiber membrane separation technologies are promising for separation of emulsions, but it is still limited by membrane fouling. Herein, a new low-pressure driving Co 3 O 4 /polyacrylonitrile (PAN) nanofiber membrane (CPNFM) with peroxymonosulfate (PMS) activation self-cleaning ability was developed by simple electrospinning technology. The effects of Co 3 O 4 dosage on the properties and structures of resulting nanofiber membranes were investigated. The results revealed excellent superhydrophilic/underwater superoleophobic properties of the optimized CPNFM even under harsh conditions, such as acid, alkali and salt. Under sole gravity-driven, the optimized CPNFM efficiently separated multiple surfactant-stabilized emulsions with high separation efficiency (>99%) and superior flux (>300 L m−2 h−1). The optimized CPNFM also displayed a good catalytic effect toward the degradation of organic dyes through PMS activation. The effective synergy of the optimized CPNFM can also efficiently separate mixed wastewater composed of emulsion and organic dyes with high efficiency (99% for emulsion and 98% for methylene blue) and superior flux (>300 L m−2 h−1). Additionally, CPNFM displayed excellent self-cleaning ability, with restored separation performance after cycling through simple PMS activation. Overall, the high separation efficiency, good stability, and self-cleaning capability of the proposed CPNFM make it a potential candidate for long-term wastewater purification. [Display omitted] • CPNFM exhibited excellent separation performance under sole gravity-driven. • CPNFM were remarkably effective in separating mixed emulsion and MB. • CPNFM possessed outstanding superwettability even under harsh conditions. • CPNFM shows excellent anti-fouling and self-cleaning ability after PMS activation. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) membranes have become a powerful separation platform in a myriad of chemical and pharmaceutical fields owing to their superior merits in high separation efficiency and low energy consuming. Despite extensive progress in exploiting polyamide thin film composite (TFC) membranes for OSN, they are heavily limited by inferior solvent permeability, especially when using conventional low-porous polyimide as TFC substrate. Herein, we report a facile substrate engineering strategy to leverage macro-porous Nylon66 microfiltration membrane to replace the conventional low-porous polyimide substrates for fabricating TFC membranes by interfacial polymerization, enabling high and robust solvent permeability during OSN. Distinct from conventional polyimide, Nylon66 substrates take advantage of their high porosity, macro-porous size and excellent hydrophilicity to realize more monomers storage and uniform monomers distribution, allowing to create crumpled and defect-free polyamide layers. With this method, the polyamide TFC membranes show a 2.1-fold increase in ethanol permeance (up to 16.0 L h−1 m−2 bar−1) meanwhile possessing 98 % rejection of dye, surpassing the most reported TFC membranes. We also demonstrate that the TFC membranes exhibit excellent long-term stability in both polar and non-polar solvent, as well as hold huge promise in the precise separation of dye mixture, pharmaceutical ingredient, and catalyst. [Display omitted] • Nylon 66 substrate is first used to prepare TFC-based organic solvent nanofiltration membranes. • TFC membranes using Nylon 66 substrate feature crumpled and defect-free polyamide layer. • TFC membranes show an ultrahigh ethanol permeance of 16.0 L h−1 m−2 bar−1 and 98 % dye rejection. • TFC membranes deliver stable precise screening ability in both polar and non-polar solvent. [ABSTRACT FROM AUTHOR]

Positively charged composite membranes with polyethylene-based antimicrobial separation layers are conveniently developed herein for precise molecular sieving. Quaternization cross-linking between hyperbranched polyethylene- graft -poly(diethylaminoethyl methacrylate) and 1,2-dibromoethane constructs porous networks with abundant quaternary ammonium groups. Modified membranes exhibit different interception capabilities for anions, cations, and neutral molecules. We explain the possible sieving mechanisms with respect to size exclusion, the Donnan effect, and the intrapore energy barrier. A strongly positively charged separation layer introduces the electrostatic interaction which has different effects on cationic, anionic, and neutral molecules during filtration. Membranes prepared by the simple quaternization cross-linking strategy can efficiently separate molecular mixtures with different dimensions or charges. Moreover, the plentiful quaternary ammonium groups endow the membranes with favorable antimicrobial activity against Gram-positive E. coli and Gram-negative S. aureus. [Display omitted] • The graft copolymer HBPE- g -PDEAEMA was successfully synthesized by ATRP. • Hyperbranched polyethylene was used to moidify membranes for the first time. • Quaternization cross-linking was used to prepare molecular sieving membranes. • The membranes can precisely distinguish molecules with different charges or sizes. • The polyethylene-based separation layer showed favorable antimicrobial activity. [ABSTRACT FROM AUTHOR]

Membrane-based separation technology for carbon capture has received increasing attention in the world due to low energy consumption, investment and operating cost. However, the simultaneous improvement in selectivity and permeance has faced large challenge for mixed matrix membranes owing to limited affinity sites and transport channels. Herein, the nano-scale MIP-202 (SM-202) was first prepared by inhibited Ostwald ripening strategy during crystal growth, and then nano-scale amorphous MIP-202 (ASM-202) was prepared by thermal chemical reaction. Subsequently, mixed matrix composite membranes (MMCMs) were developed by using ASM-202 as a filler and polyether-block-amide (Pebax) as a polymer matrix, and the hydrophilicity-modified polysulfone ultrafiltration membrane (mPSf) was utilized as a porous support. It is observed that ASM-202 possessed good miscibility with Pebax polymer chains as a result of hydrogen bonds between two phases. Thus, the as-obtained MMCMs showed outstanding CO 2 separation performance (CO 2 permeance: 936 GPU; CO 2 /N 2 selectivity: 52), which were enhanced by 138 % and 108 % over that of the pristine Pebax membrane, as well as 15.3 % and 13.0 % over that of MMCMs incorporating with SM-202, respectively. The improvement in gas separation performance can be explained by the reason that the nano-scale ASM-202 with large specific surface area afforded more unsaturated metal sites and nitrogen-doped structure, thus improving the CO 2 affinity in membranes. Moreover, the loose amorphous structure of ASM-202 provides more transport passageways, which enhanced the diffusion rate of gas molecules through the membranes. Besides, resultant MMCMs maintained great stability for over 360 h using the CO 2 /N 2 mixed gas as feed gas, whose average CO 2 permeance and CO 2 /N 2 selectivity fluctuated at 880 GPU and 47. [Display omitted] • Nano-amorphous MIP-202 was prepared by combining inhibited Ostwald ripening strategy with thermal chemical reaction. • The nano-amorphous MIP-202 enhanced CO 2 permeance and CO 2 /N 2 selectivity of MMCMs concurrently. • The nano-scale amorphous MIP-202 had good compatibility with Pebax matrix. • MMCMs revealed a CO 2 permeance of 936 GPU with a CO 2 /N 2 selectivity of 52 which was superior to that loaded with MIP-202. [ABSTRACT FROM AUTHOR]

Poly(oxymethylene) dimethyl ethers of chain lengths n = 3 to 5 (OME 3 − 5) are clean-burning synthetic diesel fuels capable of utilizing biomass and captured carbon dioxide as raw materials. In water-tolerant OME 3 − 5 production processes, separating water from mixtures containing methanol, formaldehyde, water, and short-chain OME 1 − 2 is a critical and challenging task. This work focuses on the screening of membranes for water separation from such mixtures, particularly emphasizing their selectivity towards water and stability. Among the materials investigated, a ceramic SiO 2 membrane was identified as promising. Fourteen pervaporation experiments were conducted on a continuous setup at a mini-plant scale. No deterioration in flux or permeate quality was observed across the repeated experiments. The membrane exhibited significant separation factors for all components, demonstrating its selectivity for water. However, the selectivity towards water decreased for the mini-plant experiments compared to the screening experiments. A model describing the water flux as a function of the water concentration in the feed was developed, demonstrating accurate characterization of the operation dynamics. These outcomes establish the fundamental feasibility of water separation via pervaporation using SiO 2 membranes in water-tolerant OME 3 − 5 production processes. [Display omitted] • Membrane screening for drying systems containing poly(oxymethylene) dimethyl ethers. • Mini-plant scale pervaporation experiments on a SiO 2 membrane. • Development of a model to describe the water flux. • Assessment of the SiO 2 membrane stability and water selectivity. [ABSTRACT FROM AUTHOR]

The organic solvent reverse osmosis (OSRO) separation of alcohol-hydrocarbon mixtures with Matrimid membranes is studied via experiment as well as modelling with dry glass reference perturbation theory (DGRPT). It is shown that the separation of these mixtures is highly non-ideal, with strong maxima of the separation factors as a function of feed composition. The DGRPT model was fit to pure vapor sorption data, while the Fickian diffusivities were fit from pure liquid permeation data. From this pure component parameterization, the model successfully predicted the highly non-ideal separation behavior observed for mixtures of alcohols and hydrocarbons. Successful application of the model was crucial in the interpretation of the experimental data, conclusively showing that the non-ideal behavior observed in the separations was a result of thermodynamic phenomena. Observed OSRO separation of ethanol/hydrocarbon mixtures is predictable based on bulk liquid thermodynamics, pure solvent sorption, and pure solvent permeation experiments. [Display omitted] • OSRO separations of alcohol/hydrocarbon mixtures using Matrimid membranes are studied via experiment and theory. • Alcohol/hydrocarbon binaries are studied over the full composition range at trans -membrane pressures of 20 and 40 bar. • The non-ideal phase behavior observed in bulk systems translates to the OSRO separation. • Fickian diffusion employing DGRPT to evaluate membrane solubilities accurately predicts this non-ideal behavior. • It is demonstrated that the non-ideality in the OSRO separation is a result of thermodynamic considerations. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) is a new type of organic fluid separation technology that can greatly reduce energy consumption compared with traditional distillation techniques. However, the development and application of OSN are restricted by the high manufacturing cost of solvent resistant membranes, including expensive materials and complex post-treatment process. In this paper, a low-cost polyaryletherketone bearing amino group synthesized from industrial raw material phenolphthalein was proposed, and then the crosslinked polyaryletherketone membrane with remarkable stability in polar aprotic solvent was prepared by green, mild and simple crosslinking method. The separation accuracy of the membrane can be easily adjusted from ultrafiltration to nanofiltration by altering the composition of the cast solution. In addition, the prepared membrane can be operated in DMF for 120 h, which indicated the excellent stability of the membrane, even for hash polar aprotic solvents. Therefore, this work demonstrates a novel low-cost solvent resistant membrane material that is promising for OSN applications. Schematic diagram of the preparation process of crosslinked PEK-NH 2 membranes. [Display omitted] • A novel low-cost polymer membrane material with good comprehensive performance. • Crosslinking occurs in aqueous solutions, which is a green, mild, and simple process. • The separation accuracy of the membrane can be easily adjusted from ultrafiltration to nanofiltration. • The crosslinked membranes exhibited excellent stability in common organic solvents including DMF. [ABSTRACT FROM AUTHOR]

Carbon molecular sieve membranes (CMSMs) have exhibited significant potential in gas separation applications, particularly in the realm of hydrogen and carbon dioxide separation. Poly(furfuryl alcohol) (PFA) represents a cost-efficient and sustainable precursor utilized in the synthesis of CMSMs. Nonetheless, PFA-based CMSMs have exhibited suboptimal performance and frequently necessitate supplementary supporting layers. In the present investigation, we have explored various acids as catalysts for the in-situ self-polymerization of PFA. Our findings reveal that PFA membrane catalyzed by sulfuric acid exhibits the most favorable performance, yielding a hydrogen permeability of 1394.4 Barrer and a H 2 /CH 4 selectivity of 404.1. These values exceed the Robeson upper limits established in 2019. The enhanced gas separation performance of the sulfuric acid catalyzed PFA-based CMSM could be attributed to the increased furan ring opening and higher polymerization degree achieved through this catalytic process. Furthermore, our investigation delved into the addition of poly(styrene-co-acrylonitrile) (SAN) into the PFA membrane, yielding a CMSM featuring both dense and porous layers. With the addition of 6 wt% SAN in PFA membrane, the resulting CMSM exhibited a hydrogen permeability of 3126.4 Barrer, underscoring the potential for high-performance CMSMs made from the economical PFA precursor. The optimization of the PFA polymerization process and the incorporation of SAN, hold the promise of further elevating the performance of PFA-based CMSMs, and these advancements will substantially contribute to the advancement of sustainable and efficient gas separation technologies. [Display omitted] • Self-supported CMSMs are made from a bio-derived low-cost precursor, poly(furfuryl alcohol). • The furan ring opening in PFA affects the structures and gas separation performances of the resulting CMSMs. • The addition of SAN leads to phase separation and improves the gas permeability of CMSM. [ABSTRACT FROM AUTHOR]

Grafting of oligomers into the mesopores of ceramic membranes (e.g. γ-alumina) represents an attractive strategy for deploying durable, resistant, and efficient hybrid membranes for the industrial treatment of wastewater containing organic solvents and divers solutes. In general, to control the membrane/solute/solvent interactions, homogeneous surface modification and high grafting yields are required. However, reaching this goal is rather challenging with the current grafting approaches where the active diffusion of the oligomers to the membrane pore surface may be hampered. To mitigate such diffusion limitation, we present here a novel synthesis method consisting of an infiltration of concentrated PEG organophosphonic acid oligomer solution in ceramic ultrafiltration membranes before initiating the solid-state grafting reaction to form a PEG-brush-grafted nanofiltration ceramic membrane. The infiltration step was found to be decisive for the formation of weak bonds between the oligomer linking functions and the ceramic membrane ensuring the final synthesis of robust PEG-based membranes by a grafting reaction. The influence of the solvent polarity (water vs. cyclohexane) on the conformation of the grafted PEG brush inside the γ-alumina mesopores was observed as a key parameter in the analysis of the pore size and permeability results. In addition to this, it was studied here for the first time by molecular dynamic simulations. The as-prepared PEG-brush/ceramic membranes were found very efficient in the separation of small organic dyes such as Rhodamine B (479 g mol−1) up to 85%. As a result, the present synthesis method represents a sustainable and simple alternative way for the preparation of hybrid nanofiltration membranes with controlled surface properties and attractive separation performance. Moreover, the vacuum impregnation and solid-state grafting approach requires a minimal amount of functional oligomers and solvent (0.5 mmol for 2–3 mL of solvent) and can be applied to other porous materials used in separation technologies. [Display omitted] • Nanofiltration ceramic membranes made through impregnation of organo-phosphonic acidsfollowed by solid-state reaction. • A preferential binding configuration of the linking functions is induced prior to the grafting reaction. • Diffusion limitation of polymer brushes in ceramic membranes is overcome with the controlled impregnation-grafting method. • Mechanical and thermal stable PEG-brushes grafted ceramic membranes were obtained with MWCO of around 600 Da. • The end-group of the PEG polymer brush can influence solute rejection. [ABSTRACT FROM AUTHOR]

Membrane-based separation technology offers notable advantages in terms of its compact size and energy efficiency. However, single-stage membrane processes encounter limitations in achieving high levels of purity for target gases, particularly when dealing with low feed concentrations, due to the constrained separation performance of polymeric membranes. Herein, we report on the optimization of dual-stage membrane processes for diverse gas separation applications, including CO 2 /N 2 , CO 2 /CH 4 , H 2 /N 2 , and H 2 /CH 4 separation. The optimization process involves the utilization of various membrane combinations, which are carefully selected using a user-friendly apparent selectivity model. In particular, our evaluation includes an assessment of the separation performance of the proposed membrane combinations for different molar fractions in the feed while maintaining a fixed target purity. Additionally, we determine their practical feasibility by estimating other process parameters such as the required membrane area, energy demand, and material cost. Through process analysis, it is observed that a combination of more selective membranes in the first stage and more permeable membranes in the second stage can yield economic benefits for various gas separation applications. The present study provides a practical approach to enhancing the process efficiency of a dual-stage membrane process for various gas separation applications. [Display omitted] • A practical membrane combination is proposed to enhance dual-stage process efficiency. • The dual-stage membrane process is optimized for diverse industrial gas separations. • The use of dual-stage highly selective and permeable membranes yields economic benefits. [ABSTRACT FROM AUTHOR]

Pyridine is generally found in the effluents from the synthesis of paints, rubber chemicals, vitamins, and pesticides. This study focused on improving the pervaporation (PV) performance of polyether block-amide (PEBA-2533) membranes cast on polyvinylidene fluoride (PVDF) substrate, by incorporating the MIL-53 (Al) particles to prepare mixed matrix membranes (MMMs) for pyridine separation from the aqueous solution. MIL-53 (Al) has a larger aperture size (8.5 Å) than the molecular size of the pyridine (6.0 Å), which could allow pyridine molecules to efficiently pass through its channels. The coadjacent MIL-53 particles created relatively continuous permeation pathways for the penetrants in the MMMs, which substantially enhanced the separation performance. Impressively, the resultant MMMs displayed superior pyridine separation performance at complex conditions. At 65 °C and 0.5 wt% pyridine aqueous solution, the separation factor and pyridine flux of PEBA/PVDF membrane were 17.3 and 143.5 g m−2 h−1, which were improved using MIL-53@PEBA/PVDF MMMs to 48.1 and 226.9 g m−2 h−1, respectively. Owing to the enhanced pyridine affinity, hydrophobic property, and thermal robustness, the resultant MMMs overcame the inherent trade-off between selectivity and permeability, and also displayed the promising long-term stability. These findings may provide valuable insights for developing novel MMMs with superior separation performance. [Display omitted] • PVDF supported PEBA layer embedded with MIL-53(Al) for pyridine/water PV separation. • MIL-53(Al) created relatively continuous pathways for pyridine permeation. • Hydrophobic MIL-53(Al) improved pyridine flux but reduced water flux. • The resultant MMM broke the trade-off effect between permeability and selectivity. • The resultant MMM exhibited long-term stability and reusability in harsh conditions. [ABSTRACT FROM AUTHOR]

Polymeric membranes are the most practical separation technology for extracting target ionic species necessary for water purification and clean energy, but are limited by the multi-scale heterogeneity, and transient and dynamic free volume pores. Modulated interfacial polymerization techniques are emergent concepts for preparing polyamide composite membranes with reduced thickness and homogeneous pore structures to satisfy the requirements for efficient ion separation applications. Herein, N–Cyclic cation-assisted kinetically regulated interfacial polymerization strategy to generate polyamide nanofilm composite membranes with tuned pore network and asymmetric structures for water purification is reported. Experimental characterization techniques and molecular dynamic simulations revealed that the N-Cyclic cations control the kinetic diffusion behaviour of the amine monomers to the aqueous/organic interface conducing to the formation of nanofilm membranes with fine-tuned polyamide network structures. Meanwhile, the N–Cyclic cation–regulated IP process not only affords to decrease the thickness of the formed polyamide nanofilm selective layers but also effectively narrows the effective pore size of the membranes. These membranes with thinner, homogeneous and asymmetric polyamide network structures exhibit enhanced water permeance of 55.7–60.42 L m−2 h−1 bar−1, and showed Na 2 SO 4 rejection of 99.59–99.66% and MgCl 2 rejection of 98.94–98.96% in nanofiltration separations, thereby outperforming the permeance–selectivity performance of the state-of-the-art polyamide-based membranes. The membranes also exhibit improved forward osmosis performances. We envision that this research will provide insightful foundations for the molecular tuning and construction of the next-generation structurally modulated polyamide nanofilms for various applications in molecular separation and water purification. Novel Ionic bulky N–Cyclic piperidine-based cations are used to molecularly tune the nanoscale homogeneity and microstructure of polyamide-based thin-film composite membranes via N–Cyclic cation-assisted kinetically regulated interfacial polymerization strategy. The resultant membranes with reduced thickness, homogenous pore network and asymmetric structure exhibits enhanced performances, thereby improving the permeance–selectivity trade-off of the structural polyamide membranes in nanofiltration and forward osmosis separations. [Display omitted] • Novel Ionic bulky N–Cyclic piperidine-based cations are designed and synthesized. • Polyamide-based membranes are fabricated via interfacial polymerization in the presence of N–Cyclic cations. • Steric hindrance of the N-Cyclic cations regulates the spatial distribution of amine monomers. • N-Cyclic cation-assisted regulation leads to reduced thickness, homogenous pore network and asymmetric structure. • Modified membrane exhibit enhanced performances for efficient nanofiltration and forward osmosis separations. [ABSTRACT FROM AUTHOR]

With the growing global warming and energy issues, gas separation like carbon capture and hydrogen purification are becoming increasingly important. Membrane separation technology has been preferred in gas separation due to its economic, energy-saving and environmental characteristics. As a membrane preparation method that is easy to scale up and regulate in the industry, the interfacial polymerization (IP) process has seen significant advancements in the preparation of gas separation membranes in recent years. This review summarizes the basic principles of the IP process for gas separation. In particular, the application of the IP process in the preparation of CO 2 capture membranes, H 2 purification membranes, and other gas system separation membranes is outlined for the first time, and its regulation methods are also summarized. Finally, the prospect of gas separation membrane prepared by the IP process is put forward. It is expected that this review could provide new ideas for the preparation of novel IP materials with high gas separation performance, thereby facilitating the wider application of the IP process in gas separation. [Display omitted] • The interfacial polymerization (IP) process and 'oil before water' process for gas separation membranes were introduced. • Recent progress of gas separation membranes prepared by IP in various gas separation systems were summarized. • Similarities and differences in regulation means between gas separation and water treatment IP-made membranes were shown. • The challenges and prospects of IP-made gas separation membranes in industrial applications were proposed. [ABSTRACT FROM AUTHOR]

Fractionation of dyes and salts is a great challenge in high salinity wastewater from the textile industry. In this work, a high performance loose nanofiltration membrane (LNM) was fabricated to fractionate the dyes and salts in the solution via green rapid coating (GRC) process on polyethersulfone (PES) substrate. The organic solvent-free GRC process was achieved within 10 min based on the crosslinking between polyethylenimine (PEI) and tannic acid (TA). The resultant LNM performance was optimized by altering the coating parameters including the TA concentration and the coating time. The microstructure, surface properties and dye/salt separation performance of the LNM were demonstrated by characterizations and filtration experiments, respectively. With the co-existence of dye and salt, the optimized LNM exhibited desirable permeability (40.6 LMH·bar−1) and dye rejection (99.8% for 0.1 g/L Congo Red) as well as low salt rejection (6.1% for NaCl and 2.2% for Na 2 SO 4). Furthermore, it was observed that even under 60 g/L of salt content, the satisfying rejection of CR (99.3% in Na 2 SO 4 and 97.6% in NaCl) and high permeation of salts (98.9% for Na 2 SO 4 and 97.9% for NaCl) can still be maintained. Moreover, the LNM showed incredible stability during the filtration process (10 h) towards dye/salt aqueous mixture. The PEI-TA/PES LNM exhibited promising application potential in dye/salt separation. Image 1 • A green rapid coating process to high performance loose nanofiltration membrane is reported. • This method based on the aqueous crosslinking between polyethylenimine and tannic acid. • The optimized membrane exhibited high permeability and rejection to dye solution. • The membrane recovered over 90% of salt while rejected 99.4% of CR in mixture feed. [ABSTRACT FROM AUTHOR]

Abstract N 2 /SF 6 mixtures have been widely used in gas-insulated equipment. Highly efficient separation approaches are urgently required to recycle SF 6 from the mixtures during equipment maintenance. Gas separation with glassy polymeric membranes is regarded as a promising approach due to the great size difference between SF 6 and N 2 molecules. However, the common membranes are quite low permeable for N 2 /SF 6 mixtures. In this research, the dry-wet phase inversion was customized with sectionalized air gap, i.e., dried air at upper section and humidified air at lower section, to manufacture Matrimid® asymmetric membranes in bulk with an ultrathin and defect-free selective layer. After optimization, the defect-free selective layer could be thinned to 80 nm. The pure gas test at 25 °C revealed that J N2 was increased to 2.58 GPU, and α N2/SF6 was approximately 41, very close to the value in the literature [J. Membr. Sci., 2014, 452, 311]. Without the restriction from the usual PDMS coating layer for defect-blocking, the elevated temperature operation was able to be employed to further enhance gas permeation. At 128 °C, the selectivity α N2/SF6 was maximized to 115, and the relevant J N2 is 9.0 GPU. At 200 °C, the temperature close to the allowable upper limit, J N2 was increased to 15.9 GPU, and the relevant α N2/SF6 was 97. Furthermore, the mixed-gas test demonstrated the favorable long-term stability of the customized membranes, even under the extreme running condition with pressure up to 2.0 MPaG and temperature up to 200 °C. With high efficiency and throughput under elevated temperature operation mode, the Matrimid® asymmetric membrane with ultrathin and defect-free selective layer is a promising approach for the separation and recycle of SF 6 from the N 2 /SF 6 mixtures. Graphical abstract fx1 Highlights • Phase inversion is retrofitted to fabricate high-flux defect-free membrane in bulk. • Defect-free dense layer is thinned to 80 nm by modified dry-wet phase inversion. • Customized membrane behaved excellent with α N2/SF6 = 115 & J N2 = 9.0 GPU at 128 °C. • Customized membrane has favorable long-term stability under 2.0 MPaG and 200 °C. • Customized membrane with high temperature mode is promising for N 2 /SF 6 separation. [ABSTRACT FROM AUTHOR]

Abstract Networked hybrid materials containing various types of organic imides covalently bonded with polyhedral oligomeric silsesquioxanes (POSS) have recently been developed. One of their possible applications is for gas-separation under extreme conditions of pressure and/or temperature. Experimental results indicate that their permeation properties depend on the specific organic dianhydride precursor used in the synthesis. In this work, atomistic models of 6FDA-based and PMDA-based poly(POSS-imide) crosslinked networks have been used to investigate the sorption, desorption, relaxation and permeation properties of such materials at the molecular level and their dependence on the nature of the imide linker. Results have been compared to available experimental data. A highly-efficient parallelised version of the excluded volume map sampling test particle insertion (EVMS-TPI) method was used to obtain the infinite dilution solubilities of a number of small penetrants (N 2 , O 2 , CH 4 and CO 2) in these model networks. Analyses of the Boltzmann-weighted probability densities for the distribution of the insertion energies showed that very reliable estimates of solubilities could be obtained. Extensive molecular dynamics simulations were then performed to obtain the complete model sorption isotherms for CO 2 and CH 4 at 35 °C up to pressures of over 60 bar using an iterative technique which matches the chemical potential of the penetrant in the poly(POSS-imide) phase to that in the corresponding gas phase. The sorption-induced changes in volume, the significant space available to penetrants, the mean insertion energies and their distributions were characterized. Comparisons were not only made between both types of poly(POSS-imide) to characterize the effect of the linker, but also with (hypothetical) uncrosslinked mixtures of the POSS and dianhydride molecules in order to elucidate the effects of crosslinking. Given the known conditioning properties of CO 2 , desorption isotherms were also obtained for this penetrant. These showed significant hysteresis. Prolonged exposure to high concentrations of CO 2 was also found to lead to slow relaxations that have significant effects on the solubility. Permeabilities were obtained for methane and carbon dioxide at 100 °C, 200 °C and 300 °C at a pressure of ~ 2 bar. Differences in permeabilities were largely diffusion dependent. Graphical abstract fx1 Highlights • MD simulations of gas sorption and permeation in poly(POSS-imide) inorganic-organic network hybrid materials. • Full sorption isotherms for CO2 and CH4 at 35 °C up to pressures of over 60 bar were obtained using an iterative technique. • Prolonged exposure to high concentrations of CO2 leads to slow relaxations that have significant effects on the solubility. [ABSTRACT FROM AUTHOR]

Abstract Hydrophobic and highly porous poly(vinylidene fluoride) (PVDF) membranes with isotropic cross section as well as tunable and narrow barrier pore size distribution in the range from ~0.1 to ~1 µm have been prepared using the non-solvent vapor induced phase separation (VIPS) technique. The process conditions have been tuned to suit an industrial scale up, using a short production time and dimethyl sulfoxide (DMSO) as solvent for PVDF, instead of commonly used hazardous chemicals. Factors like kind of solvent, the relative humidity of air, the exposure time to humid air and the mass fraction of PVDF in the casting solutions have been used to tune membrane characteristics. Interestingly, it was revealed that DMSO as a less common solvent for PVDF shows better qualities regarding upscaling than other more frequently used polar aprotic solvents (e.g. dimethylacetamide) when using VIPS under suited conditions. The phenomenon was explained through investigations of the membrane formation step, in particular by water uptake and cloud point measurements, as well as structure and performance analyses, e.g. by scanning electron microscopy, gas flow/liquid dewetting permpometry, gas and water vapor permeability analyses and liquid water entry pressure measurements. Lab-scale manufactured membranes showed pore characteristics and performance desired for membrane contactor applications. Furthermore, fabrication on a roll-to-roll machine using a nonwoven support and the established VIPS conditions was realized in a short manufacturing time; resulting membranes structure and characteristics were found to be similar to the ones for the lab-scale membranes. Overall, the combination of PVDF with DMSO gives promising opportunities for a more eco-friendly industrial fabrication of porous membranes with advanced properties via VIPS. Highlights • DMSO established as alternative solvent for fast and tunable preparation of porous PVDF membranes via VIPS. • Role of crucial VIPS parameters for tuning PVDF pore structure identified. • Scalability of membrane fabrication demonstrated by transfer from batch lab to semi-continuous pilot scale. [ABSTRACT FROM AUTHOR]

Abstract Well-intergrown hydrophilic CAU-10-H membranes were successfully prepared by microwave-assisted secondary growth. The as-synthesized CAU-10-H membranes exhibited high and reproducible performance for ethanol dehydration. For a 90 wt% ethanol feed, the CAU-10-H membrane had a total flux of 493 g m-2 h-1 and water/ethanol separation factor of 148 at 65 °C. Along with the increasing temperature or water feed concentration, the total flux increased while the water/ethanol separation factor decreased. The ideal water/ethanol selectivities of the CAU-10-H membranes were found to be significantly lower than its membrane selectivities, demonstrating that the preferential adsorption of water on hydrophilic CAU-10-H membrane to hinder ethanol transport played a prominent part in the ethanol-water separation. The CAU-10-H membranes are capable of being used in acidic conditions, and therefore showing great prospects for industrial applications. Highlights • Hydrophilic CAU-10-H is stable in water at 80 °C around 190 h. • A dense CAU-10-H membrane was synthesized by microwave-assisted secondary growth. • CAU-10-H membranes showed high pervaporation performance for ethanol dehydration. • The performance of CAU-10-H membranes remained unchanged under acidic conditions. [ABSTRACT FROM AUTHOR]

Abstract The development of organic solvent nanofiltration (OSN) membranes has been a continuous effort during the past decade. Several groups generated and published experimental results and simulations with either tailor-made membranes or industrial products. The published data space is diverse, with a single publication often focusing on a certain membrane only, a group of specific solutes only, on the effect of solvent only. A comprehensive comparison of all of these is still lacking. An analysis on the reliability of quantified transport parameters is missing, in particular when different analysis methods and different membrane systems are used. The technology is in its incubation phase with a need for reliable data and measurement standards to ground the process design on reliable membrane transport properties. This study uses an unprecedented extensive standard experimental procedure to measure separation characteristics of polymer membranes for the separation of organic solutes from organic solvents. For a variety of different solvents, solutes and membranes, flux and retention measurements are rigorously characterized by round robin tests at different labs using different analytical systems. This extensive collaborative study evaluates for the first time which fluctuations in results occur under comparable conditions of lab-scale experiments at different locations and which influence these have on the design of OSN processes. Utilizing the variance in the membrane transport data, a process design study and optimization is presented. For the first time ever, we report how variance in membrane transport properties can influence the process design ranging from a simple single stage system for values for the upper transport limits, to a two stage system with a permeate recirculation for mean values, to a complex three stage system for the lower limits. Graphical abstract fx1 Highlights • Standard experimental procedure to characterize OSN membranes. • High-quality rejection and flux data of membrane-solvent-solute systems. • Best case approximations of comparability from experimental data. • Statistical analysis and evaluation of results from five research groups. • Effect of uncertainties of flux and retention measurement on process design. [ABSTRACT FROM AUTHOR]

Abstract An oxygen transport membrane module capable of total 596 Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) membranes was constructed and tested under various capacities. The module is designed to operate with up to 20 bar feed pressure and a vacuum on the permeate side. The separation performance was tested with of up to 96 membranes tubes. A maximum oxygen purity of 98.9% was obtained and a maximum oxygen flux of 2.8 ml cm−2 min−1 was measured under a feed pressure of 10 bar. The maximum permeate oxygen flow rate achieved was 22 l min−1. The performance is lower than expected, for which an inhomogeneous module temperature and suboptimal flow distribution can be accounted for, as CFD simulations show. A lot of membrane breakages occurred during operation. Some reasons for that could be identified and the module could be optimized throughout the 2 years of testing. Within that time, three long term tests were performed and a maximum continuous operational time of 1800 h was achieved. Highlights • A pilot scale module operation for tubular, dead-end membranes in three-end operation is introduced. • Permeation rate, leakage rate and process control parameters of three long-term tests up to 1800 h are discussed. • Significant improvement regarding the reliability of the module was obtained by simple module design and process adaptions. [ABSTRACT FROM AUTHOR]

Abstract TiO 2 nanowires (NWs) membranes with varied wettability ranging from superhydrophilic to superhydrophobic have been facile fabricated via dip-coating for oil/water separation. Incorporating TiO 2 NWs results in the increase of roughness and the formed hierarchical structure from TiO 2 NWs micro-aggregations enlarges the wettability. Separation efficiency and permission flux of the as-prepared membranes increase first and decrease with the increment of TiO 2 NWs. These superhydrophilic/hydrophilic membranes eliminate water from oil/water mixtures and the separation efficiency declines with the increasing water contact angle until the membrane lose the oil/water separation property at around 90°. Membranes with water contact angle of 90–100° cannot separate oil/water mixtures while membranes with water contact angle larger than 120° become oil-remove type with separation efficiency around ~ 99% and high permission flux. The study illustrates that relatively large pore size (~ 15 µm) attributes to the high separation efficiency and permission flux. The synergetic effects of wettability and pore size indicate that surface wettability is critical for efficient oil/water separation. Both hydrophilic and superhydrophilic membranes show high separation efficiency and outstanding anti-fouling performances after long term oil/water separation. Graphical abstract fx1 Highlights • Membrane with varying wettability has been fabricated via coating small amount of TiO 2 nanowires; • Micro/nano hierarchical structure is formed via coating TiO 2 nanowires; • Synergetic effects of wettability and pore size on oil/water separation has been investigated; • As-prepared membrane shows outstanding anti-fouling performance after long term operation. [ABSTRACT FROM AUTHOR]

Abstract Hollow fillers with tailored nanostructures and functionalities have become promising candidates for advanced mixed matrix membranes (MMMs). Herein, polydopamine/poly (ethylene glycol) (PEG) composite microcapsules are synthesized by hard template method and embedded into the Pebax matrix to fabricate MMMs for CO 2 capture. As a well-known biomimetic adhesive, polydopamine in the capsule wall renders adequate polymer-filler interfacial adhesion. The template removal process produces through-wall mesopores, which allow rapid gas diffusion into the lumen, further significantly reducing the trans-membrane mass transfer resistance. The remaining PEG in the capsule wall not only increases CO 2 affinity, but also avoids excessive chain rigidification at polymer-filler interface. In this way, the composite capsules, compared with those without PEG, confer significantly enhanced separation performance on membranes. The optimal gas transport property of the resultant membranes is obtained with a CO 2 permeability of 510 Barrer and an ideal selectivity of 84.6 for CO 2 /N 2 at humidified state, i.e., 108%, 98% higher than those of neat Pebax membrane, respectively. In addition, owing to dopamine-enabled strong adhesion, the MMMs exhibit better stability than Pebax membrane in the long-term test at 85 °C. Graphical abstract fx1 Highlights • Hollow polydopamine/PEG composite nanoparticles (HDGs) are prepared as MMMs fillers. • Both CO 2 permeability and selectivity of the MMMs are doubled compared to Pebax. • The roles of the lumen and PEG moieties in gas transport are separately discussed. • Membrane stability at 85 °C is improved due to the strong adhesion of Pebax to HDGs. [ABSTRACT FROM AUTHOR]

Abstract The development of controlled polymerization techniques in the last decade has enabled polymer brushes to be grown from inorganic substrates with precision. Less studied are brushes grown from concave geometries of high curvature, such as mesopores, despite their application potential in the separation sciences. The method used here, surface-initiated, activators-regenerated-by-electron-transfer, atom-transfer radical polymerization (SI-ARGET-ATRP), is used to grow a polystyrene brush grown from aluminum oxide pores of 5 nm diameter, to-date the most confined geometry in which ATRP has been conducted. The brush is characterized by TGA, AFM, and FTIR, the latter two methods applied specifically to the external brush. Additionally, permporometry as well as permeability and retention measurements are used to characterize the graft within the mesopores. We show that the brush length is tunable, that the brush length is solvent-dependent, and we also demonstrate the application potential of this hybrid material as an organic solvent nanofiltration membrane. This new class of membranes shows excellent performance: a toluene permeability of 2.0 L m−2 h−1 bar−1 accompanied by a 90% rejection of diphenylanthracene (MW 330 g mol−1). Graphical abstract fx1 Highlights • Nano-tuning of 5-nm γ-alumina pores by controlled brush growth is demonstrated. • Surface-initiated ATRP has been conducted in the most confined geometry to-date. • Pore brush growth and external brush growth have competing reaction kinetics. • Toluene permeability of 2.0 L m−2 h−1 bar−1 and retention of 330 Da are achieved. [ABSTRACT FROM AUTHOR]

Abstract In this work, a comprehensive analysis of PVDF-HFP/BMImBF 4 /AgBF 4 facilitated transport membranes for olefin/paraffin separation is presented. Previous works of our research group have reported high flux and propylene selectivity under dry conditions and using synthetic gas mixtures, highlighting the promising potential of these membranes for industrial applications. This work advances in the understanding of the phenomena involved in membrane performance and moves one step forward in the knowledge of the industrial viability of this membrane system. First, the internal interactions between the silver cations and the polymer backbone, the silver salt dissociation and the silver degradation have been studied using FTIR, Raman and XPS spectroscopic techniques. Secondly, the experimental membrane performance during 110 days and working at changing relative humidity conditions in the feed gas has been assessed. Thermogravimetric techniques helped determining the water uptake capability of the facilitated transport membrane. Thirdly, real gas mixtures from a fluid catalytic cracking unit were provided by the industry and used in permeation experiments to check the membrane behavior under industrial-like conditions. The results provide experimental evidence for the previously theorized facilitated transport mechanisms and reveal a major influence of feed gas humidity on membrane performance. On the other hand, the industrial gas mixture produces no deviation from synthetic feed conditions due to trace contaminants. Finally, the carrier deactivation in long-term permeation has been quantified through a mathematical expression. Highlights • Long term PVDF-HFP/BMImBF 4 /AgBF 4 membrane performance for propylene/propane separation. • The effect of feed humidity, carrier degradation and real gas mixtures has been assessed. • The results confirm the remarkable potential of these membrane to replace distillation. [ABSTRACT FROM AUTHOR]

Abstract In this work, a series of mixed matrix membranes (MMMs) consisting of Pebax® 1657 as the main polymer matrix, poly(ethylene glycol) (PEG) derivatives with low molecular weights as additives, and graphene oxide (GO) with different loadings as a nanofiller, were prepared for CO 2 /N 2 separation. Changes in the amorphous and crystalline regions of Pebax®/PEG blend membranes and in the free volume of GO-embedded MMMs were estimated based on differential scanning calorimetry (DSC) thermograms. The fractional free volume and density of the Pebax®/PEG blend membranes were investigated according to additive models. Particularly, blending poly(ethylene glycol) methyl ethyl acrylate (PEG-MEA) with the Pebax® matrix significantly improved CO 2 permeability without sacrificing high CO 2 /N 2 selectivity. Incorporating GO nanosheets up to 0.3 wt% into the Pebax®/PEG-MEA matrix was found to have a considerable impact on increasing CO 2 /N 2 selectivity, due to largely in part to an increase in the CO 2 solubility coefficients. Upon a further increase in GO loading, both CO 2 permeability and CO 2 /N 2 selectivity decreased as a result of increasing tortuosity for gas diffusion and also GO aggregation at high GO loading content. More importantly, the Pebax®/PEG-MEA blend membrane with the optimized loading of GO, i.e., 0.3 wt% indicated outstanding anti-CO 2 plasticization resistance up to 10 bar as well as long-term stability over 100 days without significant deterioration of CO 2 /N 2 separation performance. Graphical abstract fx1 Highlights • Graphene Oxide (GO)-embedded mixed matrix membranes (MMMs) were systematically designed with two additives. • GO-embedded MMMs show both higher CO 2 permeability and CO 2 /N 2 selectivity beyond the upper bound. • The effect of GO on transport property of MMMs was explained using solution-diffusion model. • Incorporating GO nanosheets in MMMs play a significant role against CO 2 -induced plasticization. [ABSTRACT FROM AUTHOR]

Abstract Anion exchange membrane (AEMs) fouling is a serious problem influencing membrane performance during electrodialysis process(ED), which would increase power consumption and reduce water recovery. In this paper, an aliphatic anion-exchange membrane was prepared from quaternized polyvinyl alcohol (QPVA) via dual cross-linking through annealing treatment and condensation reaction to restrain the membrane water swelling. The Wu% of QPVA membrane could be reduced to 22.87 ± 0.81%. Due to the hydrophilia (59.86 ± 0.21°), negative ζ-potential surface and aliphatic matrix of QPVA, no transition time appeared under our experiment condition, indicating the QPVA membrane was scarcely fouled by SDBS. And the existence of SDBS in dilute solution generated slightly effect on the QPVA membrane resistance and only 7.47 ± 0.21% reduction of the desalination rate in ED process. Furthermore, only distilled water was used as solution or reaction media, without any harmful organic solvents, presenting an environmentally friendly route for the preparation of water-based anion-exchange membrane. So, the excellent anti-fouling performance along with green preparation of QPVA showed its remarkable prospect for desalination purpose in ED process. Graphical abstract fx1 Highlights • An aliphatic AEM (QPVA) was prepared with hydrophilia and negative ζ-potential surface. • Developed a green preparation of AEMs, using only distilled water as solution or reaction media. • The Wu% of QPVA membrane was only 22.87 ± 0.81%, far below the reported (176%). • Antifouling properties of the QPVA membrane are superior to reported membranes. [ABSTRACT FROM AUTHOR]

Abstract The efficiency of slug flow for fouling control of flat sheet (FS) membrane bioreactors (MBRs) is hindered by uneven bubble distribution leading to inhomogeneous shear stress profile on the membrane. In this work, a 3D CFD model was developed enabling prediction of the hydraulic performance of a novel aeration system designed to reduce the uneven bubble distribution in a full-scale FS MBR. Bubbles generated with aeration channel submerged in 8.0 g/L activated sludge were found to be unevenly distributed with up to 12 folds difference in gas mass flow per single nozzle. More than 41% higher gas mass flow was obtained at nozzles located at higher heights compared to lower nozzles at aeration intensities ranging from 12 m3/h to 20 m3/h. The subsequent uneven bubble distribution in membrane modules contributed to uneven shear stress distribution resulting in uneven fouling performance of the membrane module. Locating the aerator at a mediate distance of 20 cm to the membrane module (in the range of 15 cm to 25 cm) resulted in higher shear stress at locations closer to the permeate collector where higher flux occurred with a maximum 2.4 times increase in average shear stress. The CFD model was validated by comparison of the simulated height of the air column and bubble frequency with experimentally measured data obtained using a high-speed camera. Highlights • CFD model developed and validated for slug flow in flat sheet membrane bioreactors. • Aerator design influences the bubble generation and distribution in membrane module. • Distance of 20 cm from aerator to membrane base yields optimal shear distribution. [ABSTRACT FROM AUTHOR]

Abstract Poly(methyl methacrylate- co -glycidyl methacrylate) P(MMA-co-GMA) and polyethyleneimine (PEI) were blended with poly(vinylidene fluoride) (PVDF) via phase separation and allowed to undergo in situ crosslinking copolymerization to produce a superhydrophilic and underwater superoleophobic membrane for oil/water emulsion separation. The P(MMA-co-GMA) copolymer served as a crosslinker for the crosslinking copolymerization of the hydrophilic PEI polymer. Both of these polymers were chosen to reduce losses of the hydrophilic polymers typically encountered during membrane preparation. The successful preparation of these coatings was demonstrated by TGA, SEM, ATR-FTIR and XPS characterization. Blending with the hydrophilic components significantly improved the hydrophilicity of the blend PVDF membranes. The membrane became superhydrophilic and superoleophobic underwater while also exhibiting underwater anti-oil-fouling performance. The blend PVDF membrane can intercept the oil droplets while allowing water to pass through, exhibiting excellent performance for oil/water emulsion separations. In addition, the blend PVDF membrane withstands repeated use and long-term operation due to the in situ crosslinking strategy employed. Graphical abstract fx1 Highlights • An in situ crosslinking blend strategy were adopted to fabricate membrane. • Both of P(MMA-co-GMA) and PEI were chosen during membrane preparation to reduce losses of the hydrophilic additives. • The blend PVDF membrane is superhydrophilic and underwater superoleophobic. • The blend PVDF membrane exhibits excellent performance for oil/water emulsion separations. • The blend PVDF membrane withstands repeated use and long-term operation. [ABSTRACT FROM AUTHOR]

Abstract The incorporation of solid fillers into mixed matrix membranes (MMMs) is a promising approach to overcome the permeability-selectivity trade-off characteristic of polymeric membranes. However, MMMs that contain conventional fillers (e.g., zeolites, silicas, and porous carbons) usually exhibit defects due to incompatible interfaces between fillers and glassy polymers. High porosity and good robustness are also desirable properties of filler materials that enhance the gas separation performance of resulting MMMs. Herein, amine-functionalized organic porous polymers (PP-DETA and PP-menm) were synthesized and used as filler materials to yield mechanically stable MMMs that possess good CO 2 /CH 4 separation performance. We found that in comparison with the MMMs loaded with bare porous polymers (PP), composite membranes that contain amine-functionalized fillers exhibited both superior mechanical strength and more effective adhesion to glassy Matrimid® Polyimide (PI) and polysulfone (PSf) polymers. In particular, the tensile strength of 10 wt%_PP-menm@PI was measured to be 69 MPa, which was higher than 26 MPa and 33 MPa for 10 wt%_PP@PI and pure PI membrane, respectively. More importantly, both the CO 2 permeability and CO 2 /CH 4 selectivity of MMMs improved significantly after the introduction of amine-functionalized fillers. These results imply that organic porous polymers, particularly those that contain amine-functional groups, are outstanding filler materials for the fabrication of defect-free MMMs with enhanced gas separation performance. Graphical abstract fx1 Highlights • Porous polymer (PP) and amine-appended PP were synthesized and incorporated into polyimide and polysulfone membranes. • The filler-polymer adhesion was improved for amine-appended PP. • Amine-appended PP improved the mechanical strength of mixed-matrix membranes. • Incorporation of amine-appended PP significantly increased both CO 2 permeability and CO 2 /CH 4 selectivity of resulting membranes. [ABSTRACT FROM AUTHOR]

Abstract Covalent organic frameworks (COFs) represent a new family of porous polymers with highly ordered two or three-dimensional channels. Although numerous studies have been focused on the design and synthesis of COF in the form of powders, the development of COF-based separation membranes is still hampered by the challenges of COF particles agglomeration and harsh synthetic conditions. In this work, interfacial polymerization (IP) directly performed on polymeric substrates as employed in the traditional IP process of polyamide (PA) membranes is developed for the synthesis of COF-based membranes. With the moderate reaction rate between monomer pairs in corresponding aqueous and organic solutions, a conformal growth of COF crystallites directly composited with the polysulfone (PSF) ultrafiltration substrates can be realized within 1 min. The synthesis parameters including reaction time and precursor concentrations are optimized, and thus-synthesized COF/PSF membrane presents a stable rejection to dye (Congo red) of 99.5% with a high water permeance of up to 50 L m−2 h−1 bar−1, which is 2–10 times higher than that of many other membranes with similar rejection. This convenient IP process is expected to facilitate the up-scaling and real-world applications of COF-based membranes. Graphical abstract fx1 Highlights • COF-based membrane has been directly synthesized on polymeric substrates by IP. • TpPa amount is the critical factor to the performance of TpPa/PSF membrane. • TpPa/PSF membrane can effectively remove dye with a size above 1.5 nm from water. • The IP process is expected to facilitate the up-scaling of COF-based membranes. [ABSTRACT FROM AUTHOR]