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... Acid-resistant nanofiltration membranes consisting of amide and urea groups have enhanced acid stability. A polyamide-polyurea NF membrane was fabricated by the interfacial polymerization reaction of linear ethylenediamine with toluene-diisocyanate and trimesoyl chloride on a polysulfone (PSf) support layer. The optimized EDA₀.₅/TMC₀.₀₅-TDI₀.₀₅ membrane has a MgSO₄ rejection rate of 98% and was ma ...
... Composite membranes of Pd/Nb₃₀Ti₃₅Co₃₅/Pd exhibit high potential in hydrogen separation and purification applications. There are two factors, interlayer diffusion and aggregation of Pd, causing the flux degradation during long-term hydrogen permeation at high temperatures (>400 °C). HfN intermediate layer is used to restrict the interdiffusion between the Pd layer and the substrate layer. The long ...
... Highly-asymmetric metallic Ni hollow fiber membranes (NHFMs) with a dense inner skin layer and an outer porous substrate were fabricated by a modified phase inversion and sintering technique. A triple-orifice spinneret was used for spinning the hollow fiber precursors with water as the internal coagulant and a solvent-ethanol mixture as the temporary external coagulant. The hollow fiber precursors ...
asymmetric membranes; carbon; hot water treatment; hydrogen; hydrogen production; hydrophobicity; industrial applications; palladium; permeability; silane; steam; zeolites
Abstract:
... The ability to selectively remove H₂ from the product has made palladium (Pd) membrane reactor a good choice for steam reforming reaction. However, carbonaceous deposited on the surface of Pd membrane during reaction hindered its industrial application. In order to protect Pd membrane from being poisoned by water and light alcohols, a TS-1/Pd composite membrane was prepared by a facile one-step hy ...
... A novel oxidized black phosphorus nanosheet (O-bPn) is proposed to improve ion selectivity of sulfonated poly (ether ether ketone) (SPEEK) membrane for vanadium redox flow battery (VRFB). O-bPn possesses a unique two-dimensional (2D) puckered lattice structure, which could function as an effective blocker for vanadium ion permeability. Moreover, diverse oxygen-containing groups on O-bPn surface in ...
... The combination of functionalized metal organic frameworks with a polymer with structural similarity is a feasible route to enhance binary phase adhesion of hybrid membranes. Herein, we incorporate amine-modified ZIF-8 with a new type of much permeable imidazole-containing copolyimide (6FBD), which contains the bulky 2,4,6-trimethyl-1,3-diaminobenzene groups, to produce compatible MMMs with optimi ...
... Branched polybenzimidazole (PBI) derivatives with large free volume and deformation rate exhibit unexpected properties in high temperature proton exchange membranes (HTPEMs) applications. However, the weak chain entanglement of branched structure implies poor membrane-forming performance. To effectively improve the comprehensive performance of HTPEMs, a branched tqPBI polymer is prepared by direct ...
... Hybrid organosilica membranes of silver-doped bis [3-(trimethoxysilyl) propyl] amine (BTPA) were prepared via sol-gel processing followed by coordination reactions to improve the permeability and separation performance. The evolution of silver in two phases as silver ions and as nanoparticles was observed during modification of the aminosilica networks; the silver ions coordinated with amine moiet ...
... Tailoring excellent polyamide (PA) seawater reverse osmosis (SWRO) membranes for boron (B) removal is a key challenge. Herein, we developed a facile surface engineering design strategy to improve the boron removal and desalination performance of SWRO membranes by controlling the reaction kinetics of interfacial polymerization. The functional groups and density of the oligomers covering the surface ...
... The high proton conductivity of proton exchange membrane under low humidification must be maintained. In this work, an ultra-thin reinforced membrane was prepared by using hexagonal boron nitride nanosheets (h-BN), high sulfonated poly (ether-ether-ketone) (sPEEK, DS = 81.4%), and expanded polytetrafluoroethylene (ePTFE) for low-humidification proton exchange membrane fuel cell (PEMFC). A sPEEK/PT ...
... Co-based zeolitic imidazolate framework-67 (ZIF) membranes present impressive potential to be applied for efficient gas separation. However, the synthesis of ZIF-67 membrane is challenging because ZIF-67 crystals tend to nucleate and grow in the reaction solution rather than on the substrate surface. In this work, ZIF-67 membranes were developed on porous ZnO hollow fibers via in situ solvothermal ...
... The need to reduce the cost of proton exchange membranes (PEMs) leads to less usage of perfluorinated sulfonic acid (PFSA), which would definitely result in a decline in the membrane lifespan under the attack of free radicals. In this study, polytetrafluoroethylene (PTFE) is used as a reinforced material to make a thinner composite membrane due to the poor mechanical strength of the pristine membr ...
... Novel nanoporous membranes with superior permeability and exceptional molecular selectivity are highly desirable for wastewater treatment and reclamation. Herein, a 3D dual-charged multilayer membrane for efficient separation of dyes/salts is fabricated via catechol-amine chemistry surface engineering. Polyethyleneimine (PEI) is firstly coated on the hydrolyzed polyacrylonitrile substrate to const ...
... Sterically crowded organic cations are widely incorporated into aromatic polymers as anion exchange membranes (AEMs) materials to improve the chemical stability. However, due to the reduced entanglement between polymers, these AEMs suffer from poor mechanical properties, low conductivity, and insufficient water uptake, impeding their further application in alkaline fuel cells. To address these lim ...
absorption; air; hydrogen; oxidants; phosphoric acid; solvents; temperature
Abstract:
... Although phosphoric acid doped polybenzimidazole has been proposed as promising high-temperature proton exchange membrane, the poor absorption and immobilization ability of phosphoric acid in the membrane hinders its long-term stability. In this work, high-temperature proton exchange membranes with high phosphoric acid uptake and retention ability are fabricated thorough solvent casting of an alka ...
... Membrane-based separation technologies are promising for various applications such as carbon capture and storage (CCS). Herein, we report the preparation and performance of mixed matrix membranes (MMMs) for carbon dioxide (CO₂) separation. The MMMs comprise amino-functionalized metal-organic framework (MOF) nanosheets (NUS-8-NH₂) dispersed in the polymer of intrinsic microporosity 1 (PIM-1). Speci ...
... LTA type zeolitic imidazolate framework membranes denoted as ZIF-21 were synthesized and evaluated for the separation of a commodity chemical, ammonia, from nitrogen and hydrogen. Membranes were grown using secondary seeded growth. Ammonia permeances were as high as 1727 GPU, with NH₃/N₂, and NH₃/H₂ ideal selectivities of 35, and 12 respectively. ZIF-21 membranes were also evaluated for gas mixtur ...
... The membranes of V-alloys are a promising alternative to Pd-alloy membranes for ultrapure hydrogen extraction. The hydrogen solubility in V–xFe alloys (x = 3.5, 4.0, 7.1, 8.8, and 13.1 at. %) was experimentally investigated in the pressure range of 10 Pa to 1.2 × 10⁶ Pa, temperature range of 250°С–450°С, and hydrogen concentration, H/M, range of 0.004–0.65. When used as an alloying element, Fe inh ...
... Hydrogen is an emerging energy source with a wide range of applications in transportation, electricity generation, and manufacturing of important chemicals such as ammonia and methanol. Hydrogen is commonly coproduced with CO₂ using steam reforming of methane and its purification is typically achieved using energy-intensive processes such as pressure swing adsorption (PSA) and cryogenic distillati ...
... Ammonia is a leading carrier for the storage and transport of renewable hydrogen, but its deployment requires scalable technologies for efficient decomposition and purification. In this work, we report on the efficient delivery of high purity hydrogen from ammonia decomposition using a catalytic membrane reactor (CMR). Improvements to the electroless plating process reduced the Pd membrane thickne ...
... Layer-by-layer graphene oxide (GO) membrane in principle has great potential in separating Li⁺ from monovalent cations, which is achieved by their functionalized interlayer entrance. The edge effects on different monovalent ions, however, are not fully understood. Therefore, molecular dynamics simulations were utilized in this study to separately elucidate the filtration effects of three typical e ...
... To meet the exponentially rising demand for lithium, it becomes vital to develop environmentally friendly processes for its recovery from brines, salt lakes and/or seawater. In this work, novel composite lithium transport selective polymeric membranes were developed to separate lithium and magnesium ions. Hydrogen manganese oxide (HMO) (at weight percentage from 0 to 25%), polystyrene sulfonate so ...
hydrogen; magnetism; methane; oil and gas industry; permeability; ultrasonics
Abstract:
... Polycarbonate (PC) based mixed matrix membranes (MMMs) loaded with porous organic polymers as fillers exhibit very good performance in gas separation of industrial interest. Resulting MMMs show excellent compatibility between the two phases.The MMMs were prepared in less time than the reported PC-based MMMs, by controlled addition of the filler under ultrasound stirring and magnetic stirring seque ...
... Recovery of ammonia from wastewater has garnered interest due to its resource potential as fertilizers, refrigerants, and hydrogen carriers. Membrane contactors (MCs) are an effective process for ammonia recovery from wastewater streams, but the impact of membrane fouling on the process has seldom been explored. Here, we examine the dependency of membrane fouling on MC process conditions and eluci ...
... Hydrogen-bonded Organic Frameworks (HOFs), consisting of H-bonds and strong π-π interaction, are novel materials with ordered and flexible porous frameworks. With permanent porosity, HOFs are considered as a promising material for large-scale preparation of gas separation membranes owing to their superior stability. Herein, we report a novel HOF-based Mixed-Matrix Membrane (MMM) termed HOF-30@PI b ...
... As one of the green, renewable, and clean energy resources, hydrogen is widely developed and utilized throughout the world. Highly efficient membrane separation for hydrogen production is required to give promising gas permeance with enough H₂ selectivity. The membranes are desired to be produced in large-scale, fast and facile methods. Here we report for the first time a kind of freestanding MXen ...
... Covalent organic frameworks (COFs) are expected to be promising candidates as the building block for proton-exchange membranes (PEMs) due to their ordered well-defined nanopore structures with high density and tunable sizes. However, the mechanism of proton-selective transport through COF membranes is still unraveled. We herein investigate the proton-selective transport behaviors through four type ...
... Amorphous glassy perfluorinated polymers have high gas permeability, are chemically inert, thermally stable and known for their superior separation performance for several gas pairs. In the current study, the gas separation performance of copolymers of perfluoro(butenyl vinyl ether) (PBVE) and perfluoro(2,2-dimethyl-1,3-dioxole) (PDD) with two different monomer ratios, commercially known as CyclAF ...
... Catalytic propane dehydrogenation membrane reactors require membranes with highly attractive high-temperature H₂/C₃H₈ separation performance. In this work, we show that polyimide-derived asymmetric carbon molecular sieve (CMS) hollow fiber membranes with thin (∼5 μm) separation layers can provide outstanding high-temperature (up to 600 °C) H₂/C₃H₈ separation factors 2–100 folds higher than micropo ...
... Highly sulfonated carbon nano-onions (SP–CNOs) with large specific surface area are used as a new type of nanofiller in sulfonated poly(arylene ether sulfone) (SPAES) to construct and adjust the proton transfer channels efficiently. SP-CNOs are synthesized from nanometer diamonds via thermal annealing, phenylation and sulfonation, and characterized by XRD, XPS, BET, Raman and HRTEM. The obtained m ...
... The apparent degradation of alkaline fuel cells performance at reduced relative humidity (RH) drives the interest in further improving anion exchange membranes (AEMs) functionalities and/or developing alternative AEMs. Herein, we report an AEM with urea-based structure that exhibits excellent low humidity performance. Microstructure analysis and molecular dynamics simulation show that hydrogen bon ...
... To promote polyimide gas transport properties, we propose a facile technique through adjustable hydrogen bonding energy through blending polyimide (6FDA-DABA) containing –COOH groups and Tröger's base (TB) polymer without damaging polymer chemical structures. The hydrogen bonding strength between –OH groups in PI and the N atoms in TB (O–H⋯N) is well tailored via controlled thermal treatment which ...
... The purification of the product gas from dehydrogenation of liquid organic hydrogen carriers (LOHC) by using PdAg-membranes is highly promising, since the low level of impurities in the released hydrogen stream allows low pressure operation and favours the coupling with the dehydrogenation step. Motivated by our recent short-term investigations indicating an influence of these impurities on the me ...
... Protons transport profoundly affects diverse fields from proton-exchange membrane fuel cells to storing liquid hydrogen. Recent advances have extended proton-exclusive transport to the two-dimensional channels that use hydrous mechanisms for fast proton transport, where the main challenge is the limited selectivity. However, the physical and chemical properties of 2D nanosheets like GO have the po ...
... To produce hydrogen with a low CO concentration, steam methane reforming (SMR) was conducted in a Pd membrane reactor containing a methanation catalyst on the permeation side. Pd membranes were prepared by electroless plating (ELP) on porous stainless-steel and Inconel supports to achieve methanation. Compared with stainless-steel, Inconel support reduced the CO concentration by methanation. Howev ...
... New polyoxadiazole-based supported ionic liquid membranes were designed and elaborated for the first time to be used as a middle- and high-temperature polymer electrolyte membrane for fuel cell application. The proposed membrane molecular design combined hydroxyl-functionalized sulfonated polyoxadiazole, hydrophilic polyvinylpyrrolidone and specific protic ionic liquid, thus allowing elaboration o ...
... It is a grand challenge to achieve the omnifarious performance promotion of the thin film composite (TFC) nanofiltration (NF) membranes due to the mutual influence among membrane permeability, selectivity and antifouling ability. Hereon, a rational strategy denoted as hyperbranched polyester (HPE) intervened interfacial polymerization (IP) was proposed to simultaneously improve various membrane pr ...
... High-performance semi-permeable membranes play a vital role in the membrane-based separation technology for seawater and brackish water desalination. Herein, plasticizer-assisted interfacial polymerization (PAIP) was implemented to fabricate aromatic polyamide layers with improved water flux and comparable salt rejection for the first time. Specifically, plasticizer (i.e., diethyl phthalate, DEP) ...
carbon; coordination polymers; cost effectiveness; hydrogen; research and development
Abstract:
... Metal-organic frameworks (MOFs), owing to their ordered porous structure, ease of synthesis, and versatility of surface functionalization have attracted significant research interests for membrane-based separations. Zeolitic-imidazolate frameworks (ZIFs), a subclass of MOFs, have drawn the most research attention by virtue of their ease of forming high-quality membranes and potential in hydrocarbo ...
... Manipulating favorable interfacial microstructure is crucial to rationally design a high-performance mixed matrix membrane with defect-free interface. We describe herein an efficient pathway to finely tune the interfacial adhesion through balancing the metal organic frameworks and polymer functionality. The varied number of hydrogen bonds are established involving the CHO groups in hybrid ZIF-8-90 ...
... Lack of high-performance membrane seriously limits the performance of non-aqueous redox flow batteries (NARFBs). Here, a porous poly(vinylidene fluoride) (PVDF) membrane with 2D vermiculite nanosheets modification is proposed and prepared. The vermiculite nanosheets act as barriers to alleviate the crossover of active species. The hydrogen bonding between vermiculite and PVDF skeleton effectively ...
... Nonsolvent-induced phase separation (NIPS) is widely used to prepare asymmetric gas separation membranes. Most industrial NIPS casting solution formulations are limited to a small group of glassy polymers and, importantly, require toxic polar aprotic solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), or N-methyl-2-pyrrolidone (NMP). Growing restrictions on the use of such ...
... Abundant in municipal, agricultural, and industrial wastewaters, ammonia is a versatile chemical, which can be used as fertilizer or as a hydrogen carrier for the hydrogen economy. Membrane contactors (MCs) are an effective membrane process for selectively recovering ammonia from a wastewater stream, but the system’s continuous acid consumption and the residual acidity in the produced stream remai ...
... The cation segregation in a perovskite-type membrane deleteriously affects the membrane performance and durability. Recovery of segregation is a great challenge because of the complexity of segregation products and severe limitations from the stability of perovskite oxide. This work presents a novel approach for reversing the surface cation segregation by hydrogen-induced annealing which further s ...
... Manufacturing defect-free mixed matrix membranes (MMMs) especially with high nanoparticle concentrations exceeding 40 wt% is still an ongoing challenge. Desired performance improvements are often unfulfilled in MMMs with high filler loading because nanoparticles with increasing contents are prone to aggregating, forming non-selective cavities, and deteriorating membrane's mechanical properties. To ...
... Mixed matrix membranes (MMMs) combine the advantages of porous fillers and polymer membranes, endowing them with potential applications in gas separation. Due to their high porosity and defined pore sizes, metal‒organic frameworks (MOFs) have been extensively investigated as MMM fillers. However, the frameworks of many MOFs are flexible, which may limit selectivity. Here, hydrogen bonding between ...
carbon; hydrogen; hydrophilicity; hydrophobicity; migratory behavior; molecular dynamics; separation; thermoplastics; trimethylamine; water treatment; water vapor; zwitterions
Abstract:
... Improving the surface hydrophilicity of the membrane can effectively deal with the membrane fouling problem in the water treatment process. In this work, the molecular dynamics (MD) simulation method was adopted to simulate the vapor induced phase separation (VIPS) process in the preparation of trimethylamine oxide-derived zwitterionic polymer-grafted polyvinylidene fluoride (PVDF-g-PTMAO) membran ...
... Ion beam sputtering (IBS) was used to deposit Mo₂C catalytic layers on vanadium (V) foils and to prepare Mo₂C/V composite membranes for hydrogen separation and purification. It is found that the sputtering temperature during IBS largely affects the structure and catalytic activity of the as-deposited Mo₂C films. A high sputtering temperature facilitates the growth of cubic Mo₂C along the catalytic ...
... Sulfonated multiblock poly(phenylene-co-arylene ether sulfone) (SmPPES) membranes for application in polymer electrolyte membrane fuel cells are prepared via Colon's Nickel catalyzed cross-coupling reaction. Their chemical stabilities and proton transport abilities are examined as functions of ion-exchange capacity (IEC) and hydrophilic (sulfonated phenylene) and hydrophobic (arylene ether sulfone ...
... Efficient separation and recovery of ammonia (NH₃) is essential for environmental protection and resource utilization. In this work, hybrid membranes for NH₃ separation through multiple-site interaction were developed by combining the unique features of ionic liquids (ILs) and a midblock-sulfonated block copolymer. The functionalized ILs ([2-Mim][NTf₂] and [Im][NTf₂]) with ammonia interaction site ...