Ether Sulfone Research Articles

Quaternary Ammonium-Functionalized Poly(Arylene Ether Sulfone) Random Copolymers for Direct Air Capture

Quaternary Ammonium-Functionalized Poly(Arylene Ether Sulfone) Random Copolymers for Direct Air Capture

Some Aspects of the Synthesis, Characterization and Modification of Poly(ether)sulfone Polymeric Membrane for Removal of Persistent Organic Pollutants in Wastewater Samples

Some Aspects of the Synthesis, Characterization and Modification of Poly(ether)sulfone Polymeric Membrane for Removal of Persistent Organic Pollutants in Wastewater Samples

Sulfonated Poly Ether Sulfone Membrane Reinforced with Bismuth-Based Organic and Inorganic Additives for Fuel Cells.

This research work focuses on developing a robust polymer electrolyte membrane (PEM) with high proton efficiency toward proton exchange membrane fuel cells (PEMFCs). In this study, poly ether sulfone (PES) was sulfonated by chlorosulfonic acid to yield sulfonated poly ether sulfone (SPES) followed by incorporation with bismuth-based additives such as bismuth trimesic acid (BiTMA) and bismuth molybdenum oxide (Bi2MoO6). The composite membrane was thoroughly investigated for its structural and physicochemical properties such as FT-IR, SEM, TGA, contact angle, water uptake, oxidative stability, ion-exchange capacity, and swelling ratio. Incorporation of additives into the polymer was confirmed by XPS and XRD analysis. The proton conductance of the pristine SPES is 4.19 × 10-3 S cm-1, whereas that of the composite membrane SPES/BiTMA-10 is 10 × 10-3 S cm-1 and that of SPES/Bi2MoO6-15 is 7.314 × 10-3 S cm-1; both the composite membranes exhibit higher proton conductivity than the pristine SPES membrane. The physicochemical characteristics and impedance measurements of the electrolyte reported can be viable to the PEM membrane.

Thermo-Sensitive Microgel/Poly(ether sulfone) Composited Ultrafiltration Membranes.

Thermo-sensitive microgels known as PMO-MGs were synthesized via surfactant free emulsion polymerization, with poly(ethylene glycol) methacrylate (OEGMA475) and 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA) used as the monomers and N, N-methylene-bis-acrylamide used as the crosslinker. PMO-MGs are spherical in shape and have an average diameter of 323 ± 12 nm, as determined via transmission electron microscopy. PMO-MGs/poly (ether sulfone) (PES) composited ultrafiltration membranes were then successfully prepared via the non-solvent-induced phase separation (NIPS) method using a PMO-MG and PES mixed solution as the casting solution. The obtained membranes were systematically characterized via combined X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and contact angle goniometer techniques. It was found that the presence of PMO-MGs significantly improved the surface hydrophilicity and antifouling performance of the obtained membranes and the PMO-MGs mainly located on the channel surface of the membranes. At 20 °C, the pure water flux increased from 217.6 L·m-2·h-1 for pure PES membrane (M00) to 369.7 L·m-2·h-1 for PMO-MGs/PES composited membrane (M20) fabricated using the casting solution with 20-weight by percentage microgels. The incorporation of PMO-MGs also gave the composited membranes a thermo-sensitive character. When the temperature increased from 20 to 45 °C, the pure water flux of M20 membrane was enhanced from 369.7 to 618.7 L·m-2·h-1.

Quaternary ammonium-functionalized crosslinked poly(aryl ether sulfone)s anion exchange membranes with enhanced alkaline stability for water electrolysis

Quaternary ammonium-functionalized anion exchange membranes (AEMs) have important potential application value in water electrolysis. In order to further improve the ionic conductivity and stability of AEMs, a series of crosslinked AEMs based on poly (aryl ether sulfone)s (Co-PAES-QA-x-m, “x” represents the functionalized polymer segment, “m” represents the crosslinking ratio) are prepared by introducing dense quaternary ammonium cations on the side chains via Menshutkin reaction. Their polymer structures are characterized by hydrogen nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy FT-IR, and the microscopic phase separation structure of the obtained membranes is observed by atomic force microscope AFM. The ion exchange capacity (IEC) of Co-PAES-QA-x-m (x = 25%, m = 40%–100%) is between 2.03–2.48 mmol g−1, and their water uptake (WU), swelling ratio (SR) and ionic conductivity are in the range of 26.9–56.7%, 6.3–12.9% and 53.43–119.43 mS cm−1 at 80 °C, respectively. The test of chemical stability show that the ionic conductivity retention ratio of these AEMs reaches 84.7% after soaking in 2 mol L−1 NaOH solution for 480 h at 80 °C. The water electrolyzer assembled with representative Co-PAES-QA-25-60 reaches 1646.7 mA cm−2 in 2 mol L−1 NaOH solution at 2.0 V and 80 °C, and the durability test shows that its voltage only rises by 5% after 480 h at the current density of 500 mA cm−2. This work is expected to provide an effective modification method for high-performance AEMs which are used in water electrolyzer.

A novel porous asymmetric cation exchange membrane with thin selective layer for efficient electrodialysis desalination

Ion exchange membranes (IEMs) are widely used in various electrochemical fields. Generally, identifying a solution for the trade-off between ion conductivity and dimensional stability is crucial for the further development of IEMs in the electrodialysis (ED) process. This study aimed to prepare a novel type of cation exchange membrane for electrodialysis desalination. Different from the previous cation exchange membranes with the thick and dense cross-section structure, the as-prepared asymmetric composite membranes in the present work composed of a thin and dense skin layer and a porous support layer via the pore-filling process of the skin layer of the porous poly (ether sulfone) (PES) membrane. Benefiting from such structural features, effective ion transport and dimensional stability were simultaneously achieved in the case of low ion exchange capacity. Ultimately, the optimal sulfonated poly (ether sulfone)-poly (ether sulfone) (SPES-PES) composite membrane simultaneously achieved ion transport enhancement, low swelling rate at 80 °C, and better mechanical stability compared to pure sulfonated poly (ether sulfone) (SPES) membranes. When applied to ED, the prepared 40 %SPES-PES membrane exhibited more excellent desalination performance (91.9%), higher current efficiency (127.5%), and lower energy loss (5.55 Kw·h·kg−1) compared to commercial membrane.

Synthesis of novel heat-resistant and soluble poly(aryl ether sulfone ketone)s containing ether-type bisphthalazinone moiety

A series of poly(bisphthalazinone ether sulfone ketone)s with pendant phenyl groups (POPESKs) were synthesized via aromatic nucleophilic substitution polycondensation. The thermal degradation mechanism of POPESKs was determined investigated by TG-FTIR. The Tgs of POPESKs range from 296 to 326 °C and the storage modulus retention is up to 46.1 % at 290 °C. POPESKs have good solubility in dichloroethane, chloroform, tetrachloroethane, N-methyl-2-pyrrolidone and pyridine, and exhibit good film-forming property. The tensile strength, tensile modulus, and tensile elongation of POPESK films are 85–96 MPa, 1.34–1.86 GPa, and 8.9–11.6 %, respectively. Meanwhile, the polymer films exhibit the high light transmittance of up to 83 % at 800 nm and its water contact angle are in the range of 82.3–94.3°. Its superior overall performance shows great potential in aerospace, petrochemical and energy applications.

Pore filled solid electrolytes with high ionic conduction and electrochemical stability for lithium sulfur battery

High lithium (Li)-ion conductive solid electrolytes with mechanical stability are quite important in the development of long-term safe and high-performance solid-state Li-sulfur batteries (LSBs). Accordingly, we prepared a pore-filling solid electrolyte (PFSE) by introducing poly(ethylene glycol) double-grafted (poly(arylene ether sulfone) (PAES-g-2PEG), ionic liquid (IL), and ethylene carbonate (EC) into a porous polypropylene/polyethylene/polypropylene (PP/PE/PP) substrate. While the PP/PE/PP substrate provides the membrane with the mechanical strength, the PAES-g-2PEG filler provides high Li-ion conductivity due to the facile ion conduction pathway formation via percolation in the presence of IL and EC. This synergistic effect allowed the prepared PFSE membranes to exhibit both high mechanical strength of 200 MPa, thermal stability above 150 °C, and high ion conductivity of 0.604 mS cm-1 with a Li-transfer number of 0.41. Moreover, PFSE membranes also achieved a large electrochemical potential window of 4.60 V and high cyclic stability after 500 h of Li-stripping/plating. The LSB cell based on a PFSE membrane showed excellent electrochemical performance with preserving 95% of initial capacity after 200 cycles at a 0.2 C-rate.

Fluorinated Sulfonated Poly(ether sulfone)‐Based Poly(3,4‐ethylenedioxythiophene) Dispersion: A Hole Transport Layer Material in Organic Solar Cells

AbstractHere the synthesis of poly(3,4‐ethylenedioxythiophene) (PEDOT) aqueous dispersion using sulfonated poly(ether sulfone) (SPES) with hydrophobic fluorinated groups to improve the weather and water stability of the conductive film is reported. The conductivity and surface morphology of the fabricated PEDOT:SPES conductive thin films are investigated. The PEDOT:SPES film after the N,N‐dimethylformamide (DMF) treatment showed a 200 times increase in the conductivity and the transmittance is over 96.5%. Raman spectroscopy indicates conformational changes in PEDOT chains due to the solvent treatment. The PEDOT:SPES film shows better water and weather stability performance in terms of dimensional stability in comparison to the commercial PEDOT:poly(styrene sulfonic acid) (PSS). Further, the organic solar cells performance is tested using PEDOT:SPES as hole transport layer and poly(3‐hexylthiophene) (P3HT):[6,6]‐phenyl C71‐butyric acid methyl ester (PC71BM) as active material. The PEDOT:SPES achieves a good power conversion efficiency (=3.36%), comparable with the conventional PEDOT:PSS (AI 4083).

Sulfonated Polyphenylene-Based Multiblock Membranes with Fluorine Moiety for Fuel Cell Applications

Sulfonated poly(phenylene-co-arylene ether sulfone) multiblock copolymers are synthesized via Colon’s nickel-mediated cross-coupling reaction and are investigated as a proton-exchange membrane fuel cell. To investigate the influence of the fluorine moieties on the membrane properties, two different membranes are prepared, one containing a fluorinated hydrophobic poly(arylene ether) block (6F polymer membrane) and a nonfluorinated biphenyl (BP) polymer membrane. The proton transport, morphology, mechanical properties, and oxidative stabilities of the membranes are examined in relation to the ion-exchange capacity (IEC). 6F polymer membranes show superior proton conductivity and oxidative stability (results of Fenton’s oxidative stability and hydrogen peroxide exposure tests) compared with the BP polymer membranes. In water at 25°C, 6F and BP polymer membranes with IEC 2.0 meq g–1 exhibit proton conductivity of 0.11 S cm–1 with 6F having 16% lower water uptake than BP polymer. Meanwhile, at 30% RH and 80°C, 6F-X5Y9-(2.0) exhibits proton conductivity of 0.0026 S cm–1 that almost 50% higher than BP-X5Y7-(2.0) with 0.0018 S cm–1, while at 90% RH and 80°C, both polymers have an almost similar value of 0.10 S cm–1. Oxidative stability with the Fenton test under harsh conditions demonstrates that 6F-X5Y9-(2.0) has an extent degradation of 26%, almost 19% lower than BP-X5Y7-(2.0) with 32%, and the hydrogen peroxide exposure test demonstrates that 6F has 50% lower extent of degradation than BP with 5 and 9%, respectively. Fuel cell performance test at 80°C and 100% RH show that 6F-X5Y9-(2.0) exhibits a current density of 1.6 A cm–2 at 0.6 V (hydrogen/air) and outperforms Nafion-NR211 and BP-X5Y7-(2.0), 1.4 A cm–2 and 1.2 A cm–2, respectively. Undoubtedly, incorporating fluorinated moieties could enhance proton transport properties and oxidative stability favorable for fuel cell application.

Polyvinylidene Fluoride (PVDF) / Poly (Ether Sulfones) (PES) Blend Membrane For CO2/CH4 Separation

In this study, a combination of Polyvinylidene fluoride (PVDF) and Poly (ether sulfones) (PES) blend membrane and DMF as solvent component was developed to evaluate the CO2 and CH4 separation performance. The gas permeation test was thereafter conducted on the membrane produced. The separation through a membrane works on the theory of permeation based on permeability and selectivity. These two important values were estimated using a set of analytical functions. The membranes produced was then characterized using scanning electron microscopy (SEM) and the Fourier Transform Infrared Spectroscopy (FTIR). The result obtained revealed that a higher permeability for the CO2 and CH4 gases when the blending ratio of membrane and solvent of PVDF:PES:DMF/ 5:15:80 were applied. Moreover, the selectivity results showed that the use of the blending ratio of PVDF:PES:DMF/ 20:0:80 produce the highest selectivity (1.3086 GPU) while blending ratio of PVDF:PES:DMF/ 10:10:80 exhibited the least selectivity. In addition, the morphological elucidation revealed the presence of pores for every cross-section composite membrane and this aids the permeability properties of the membrane aggregates at different blending ratio. Also, the FTIR results showed nearly similar functional group characteristics.

Synthesis of novel poly (aryl ether sulfone) containing amino groups for gas separation membrane

A series of poly (aryl ether sulfone) containing different contents of amino groups (ABPFx) were synthesized by nucleophilic polycondensation reaction. The ABPFx has excellent thermal resistance with the Tg reaching 277 °C as well as maintains good mechanical and film-forming properties. Particularly, the ABPF10 membrane exhibits high gas permeability [P (H2) = 22.24 Bar] and gas selectivity [α (H2/N2) = 63.5]. Consequently, the ABPFx membranes have potential application value in the field of gas separation for hydrogen separation.

Novel uremic metabolite-based zwitterionic polyethersulfone (PES) hemodialysis membrane for improved hemocompatibility: Towards the fourth generation of hemodialysis modifiers

ESRD patients suffer from side effects of the dialysis process. Comprehension of different operational parameters’ effect on the hemocompatibility profiles of the separative membranes, i.e. dialyzers, could result in designing more compatible materials. This study includes a computational approach to assess the effect of pH by assessing different uremic metabolites' behavior. The pH effect was assessed by comparing the water interaction ability of different uremic metabolites (which appear at different bloodstream pH levels) using molecular dynamics (MD) simulations. Based on the findings of the studies, a new class of zwitterionic materials is introduced. The proposed modification, containing guanidine (GNDM) was experimentally implemented on poly ether sulfone (PES) membranes. Aminolysis and sultone-ring opening reactions were used to immobilize the zwitterionic structure. Attuned total reflectance-Furrier transmission infrared spectroscopy (ATR-FTIR) was used to characterize the functional groups of the modified membrane. Gravimetry was used to measure the amount of modification layer added to the membrane as well as the equilibrium water content (EWC). Atomic force microscopy (AFM) was used to measure the roughness patterns of the neat and modified membranes. Zeta potential analyzer was used to check the trend of surface charge variations. Differential scanning calorimetry (DSC) was used to assess the stable water content of the membranes. A filtration test was performed to check the stability of the immobilized materials on the membranes. The newly modified PES membranes were nearly 50 % smoother and negatively charged. DSC reflects a 16 % higher content of stable water for the modified membranes. Computational assessments also reflected that the modified structure created more hydrogen bonds and could keep the water molecules more stable on the surface of the membrane. As the new membrane owned a higher capability to keep the water more stable on its surface, it could be a perfect candidate for a hemocompatible dialysis membrane.

Poly(3,4-ethylenedioxythiophene) dispersion in water free organic solvents using sulfonated poly(ether sulfone) as new polymeric template

Poly(3,4-ethylenedioxythiophene) dispersion in water free organic solvents using sulfonated poly(ether sulfone) as new polymeric template

PPy-NTs/C/TiO2/poly(ether sulfone) porous composite membrane: Efficient ultrafiltration of Evans blue dye from industrial wastewater

Developing a high-performance composite membrane with excellent flexibility in dye filtration remains a big challenge. Polypyrrole nanotubes (PPy-NTs), polypyrrole nanotubes/C (PPy-NTs/C), and polypyrrole nanotubes/C/TiO2(PPy-NTs/C/TiO2) modified porous poly(ether sulfone), assigned as (PPy-NTs/PES; PPy-NTs/C/PES; PPy-NTs/C/TiO2/PES) membranes, are prepared and employed in ultrafiltration of Evans blue anionic dye (EB) from industrial and municipal wastewater. X-ray diffraction, Fourier transform infrared-attenuated total reflectance, and field emission scanning electron microscope were used to characterize the composite membranes. In the adsorption investigations, experiments were conducted under different factors, including temperature (25–45 °C), stirring time, solution pH (2–12), adsorbent dosage (1–5 g/L), and initial dye concentrations (10–50 mg/L), to establish the ideal conditions. According to the experiments, at pH = 7 and 25 °C, the elimination percentage of Evans blue (EB) anionic dye might reach up to 99 %. Additionally, many isotherm models, including Freundlich and Langmuir, were used. Based on the correlation coefficients, the Freundlish isotherm model was the most suitable model (R2 = 0.9974).

In-situ fabrication of titanium suboxide-laser induced graphene composites: Removal of organic pollutants and MS2 Bacteriophage

Titanium suboxides (TSO) are identified as a series of compounds showing excellent electro- and photo-chemical properties. TSO composites with carbon-based materials such as graphene have further improved water splitting and pollutant removal performance. However, their expensive and multi-step synthesis limits their wide-scale use. Furthermore, recently discovered laser-induced graphene (LIG) is a single-step and low-cost fabrication of graphene-based composites. Moreover, LIG's highly electrically conductive surface aids in tremendous environmental applications, including bacterial inactivation, anti-biofouling, and pollutant sensing. Here, we demonstrate the single-step in-situ fabrication of TSO-LIG composite by directly scribing the TiO2 mixed poly(ether) sulfone sheets using a CO2 infrared laser. In contrast, earlier composites were derived from either commercial-grade TSO or synthesized TSO with graphene in multi step processes. The characteristic Ti3+ peaks in XPS confirmed the conversion of TiO2 into its sub-stoichiometric form, enhancing the electro-catalytical properties of the LIG-TiOx composite surface. Electrochemical characterization, including impedance spectroscopy, validated the surface's enhanced electrochemical activity and electrode stability. Furthermore, the LIG-TiOx composite surfaces were tested for anti-biofouling action and electrochemical application as electrodes and filters. The composite electrodes exhibit enhanced degradation performance for removing emerging pollutant antibiotics ciprofloxacin and methylene blue due to the in-situ hydroxyl radical generation. Additionally, the LIG-TiOx conductive filters showed the complete 6-log killing of mixed bacterial culture and MS2 phage virus in flow-through filtration mode at 2.5 V, which is ∼2.5-log more killing compared to non-composited LIG filers at 500 Lm−2h−1. Nevertheless, these cost-effective LIG-TiOx composites have excellent electrical properties and can be effectively utilized for energy and environmental applications.

Preparation of biomolecules-mimic poly (ether sulfone)-based hydrogels and their anti-thrombotic, endothelialization and anti-microbial properties

The development of novel hydrogels with high biocompatibility is a vital and active topic of study. Here, we used a facile polycondensation approach to develop multifunctional poly (ether sulfone) (PES)-based hydrogels with diverse functional groups (−SO3Na, −COONa, −OH, and − NH2), as indicated by flourier transformed infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The chemical structure of the PES-based hydrogels could be modulated by monomer selection and post-treatment, resulting in a wide range of biomolecule-mimic structures and matching biological functions. In the current investigation, heparin-mimic PES-based hydrogels demonstrated good hemocompatibility, as evident by reduced platelet adhesion and activation, delayed clotting times, suppressed blood-related complement activations, and CD11b expression on leukocytes in the blood. Moreover, hyper-sulfonated PES-based hydrogels showed exceptional cytocompatibility with human umbilical vein endothelial cells (HUVECs) and considerable antiproliferative activity against human umbilical artery smooth muscle cells (HUASMCs), as revealed by cell proliferation and cytotoxicity assay findings. Finally, chitosan-mimic PES-based hydrogels had marked anti-microbial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as shown by the number of colonies. The aforementioned bio-functions were attributed to the formation of various chemical structures on the surfaces of PES-based hydrogels. The distinctive PES-based hydrogels synthesized in this work would be of high utility not only in the synthesis of biomedical hydrogels but also in the rational design of various types of biocompatible materials.

Antifouling Polydopamine-Modified Poly (ether sulfone) Membrane Immobilized With Alumina-Calcium Oxide Catalyst For Continuous Biodiesel Production

Biodiesel is an alternative biofuel that can be blended with conventional petroleum-derived diesel fuel to partly reduce the dependence on the imported oil. Catalytic membrane reactors are promising candidates for sustainable biodiesel production. Herein, we report a novel catalytically active polydopamine-modified poly (ether sulfone) (PES) membrane immobilized with an alumina-calcium oxide catalyst. The reaction temperature, butanol to canola oil ratio, and transmembrane pressure applied through the membrane were optimized with response surface methodology and Box–Behnken design. In contrast to all previous catalytic membrane studies for biodiesel production, we used butanol as a co-reactant to improve the winter problems of biodiesel made with methanol. FTIR and SEM-EDX analysis confirmed the successful immobilization of the catalyst. At the end of 30 days of storage in the reactant mixture, 95% of the catalyst loaded to the membrane was still on the surface, and biodiesel yield values and butanol flux of the membrane did not change. We compared the batch and flow-through operation modes by measuring the catalytic activity of membranes under static and dynamic conditions within 24 h (8-cycle). The biodiesel yield under dynamic condition decreased in the first three cycles from 54.54 ± 0.65% to 47.31 ± 0.70% and then stayed constant, whereas a continuous decrease from 25.42 ± 0.57% to 17.19 ± 0.58% was observed under static condition. In each cycle, the equilibrium limitation for the yield was overcome only when the membrane was operated under pressure. The main reason for the decrease in catalytic activities was the fouling on the catalyst surface which was quickly removed by backwashing with butanol. It is concluded that catalytic membranes with antifouling properties and alcohol stability can make biodiesel production more cost-effective and environmentally friendly.

Electrically Conductive Ni-P Nanoporous Membrane Reactors for Electrochemical Reductive Dechlorination of Organic Pollutants

Transition-metal phosphides (TMPs) are emerging electrocatalysts for both hydrogen evolution and the conversion of reactants/contaminants by various electrochemical reactions. TMPs are promising catalysts because they are earth abundant, have high electrical conductivity, and have high chemical stability. In this seminal work, a low-priced nickel phosphorus (Ni-P) ultrafiltration membrane was fabricated and used for electrochemical reductive dechlorination of chlorophenols. Amorphous Ni-P nanoparticles were grown on an ultrafiltration poly(ether sulfone) (PES) membrane via electroless deposition. The prepared Ni-P membrane was used as a cathode for electrochemical reductive dechlorination of 2-chlorophenol (2-CP) in flow-through mode. It was observed that a dechlorination efficiency of 42.7%, a reaction rate constant of 1.621 min–1, and a Faradaic efficiency of 24.5% were achieved at an optimized cathodic potential of −2.50 V. The dechlorination was primarily attributed to the partial positively charged Niδ+ on the Ni-P membrane surface, which facilitated atomic H* evolution by forming reactive Ni–H* bonds for dechlorination. Additionally, doping P atoms in Ni retarded the deactivation of electrocatalytic Ni sites. This work demonstrates that the cost-effective Ni-P membrane electrocatalyst is a promising technology to degrade chlorinated compounds with applications to industrial wastewaters and landfill leachates.

Ultra/loose nano-filtration polyarylene ether sulfone membranes with reversibly tunable pore size enabled via amine oxide units

Developing a new generation of polymer membranes with switchable pores for multiple separation processes remains challenging due to the lack of materials with reversible and adjustable chemical structures. Herein, amine oxide units were introduced in the chains of poly (arylene ether sulfone) via oxidizing the tertiary amine (TA) in poly (arylene ether sulfone)/amide tertiary amine (PAES/ATA) copolymer, and then served as switches to tune the pores of the prepared membranes. The smart membranes could be reversibly tuned between loose nanofiltration mode with water permeance of 178 L m−2 h−1 bar−1 and dye (e.g., Rhodamine B) rejection of 95%, and ultrafiltration mode, with water permeance of 650 L m−2 h−1 bar−1 and dye rejection of 55%, by cyclic acid-alkali treatment. The mechanism of the switchable pore size was elucidated by dissipative particle dynamics (DPD) simulations, and the results were in good agreement with experimental results. This study provides a novel and facile route to fabricate functional membranes with reversibly tunable and highly efficient filtration performance, which could be applicable to multiple separations.