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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 ...
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 ...
... Ionic liquids bearing acidic anions are intrinsically proton-conductive but mechanically weak for device application. Maintaining ionic conductivities after solidifying ionic liquids by polymerization remains a challenge due to the restriction of ion mobility. In this work, nanolayered ionic membranes bearing aligned acidic hydrogen sulfate anions are prepared from ionic liquid crystals for enhanc ...
... Ultra-thin membranes have significant potential for the gas separation. However, the fabrication of ultra-thin membrane with high selectivity and permeance remains a challenge. Herein, we develop a high-performance hydrogen separation membrane using atomic layer deposition (ALD) method to deposit ultra-thin Al₂O₃ layer (ALD-Al₂O₃) on a porous anodic aluminum oxide (AAO) support. The pore openings ...
... Graphene oxide (GO) nanolayer, combining extraordinary mechanical properties, separation performance and chemical stability, holds great promise for widespread applications. The current preparation of GO nanolayer is complex and requires expensive and technical equipment, which limits the further development. In this work, we deposit GO nanolayer on TiO₂ modified Polytetrafluoroethylene (PTFE) fil ...
catalysts; hydrogen; methane; oxidation; oxygen; reaction kinetics; synthesis gas; temperature
Abstract:
... The catalytic membrane reactor, a kind of process intensification technology, can enhance chemical engineering efficiencies by combining multi-steps of reaction and separation into one unit. However, the prerequisite to realize such a promising technology is the good match between reaction efficiency, transport rate and membrane stability to withstand the real reacting conditions particularly for ...
... 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 ...
... This study presents a layer-by-layer interfacial polymerization approach to enhance the chlorine resistance and water permeability of thin-film composite (TFC) polyamide (PA) forward osmosis membranes. The PA film was prepared by self-polymerization using 3,5-Dihydroxybenzoic acid (DHBA) and trimesoyl chloride (TMC) with addition of 4-amino-benzene sulfonamide (4-ABSA), which is a sulfonamide mono ...
... 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 ...
... Hydrogen transporting mixed ionic and electronic membranes offer tremendous opportunities for process intensification and energy savings in various applications such as reaction chemistries and heat/energy generation. Over the past several decades there has been significant advancement in the membrane materials science to produce improved molecular transport, but commercial adoption is still limit ...
... 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 ...
... 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 ...
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 ...
... Graphene oxide (GO) membranes have received considerable interest for separation. The channels in GO membranes are in an atomic scale and thus it is challenging to unravel underlying separation mechanism via experiment. In this study, we model multilayered GO membranes with various channel widths (W) and oxidation degrees (O/C), subsequently simulate their performance for bioethanol (an ethanol/wa ...
ambient temperature; dimensional stability; electric potential difference; electrolytes; fuels; graphene oxide; hydrogen; hydrogen fuel cells; ion exchange capacity; nanohybrids; nanosheets; oxidation; permeability; polymers; sulfonic acids; thermal stability; water uptake
Abstract:
... The high proton conductivity of graphene oxide (GO) under humidified conditions has attracted exceptional attention in many applications including fuel cells. However, the proton conductivity of GO membrane (GOM) is much lower than that of high-performance polymer electrolyte such as Nafion®, and in contact with hydrogen gas in fuel cells, the loss of surface functional groups due to reduction by ...
... Graphitic carbon nitride nanosheets can be assembled into two-dimensional layered separation membranes due to their unique structure; however, the narrow interlayer channels (0.32 nm) cause strong transmembrane mass transfer resistance. In this study, we expanded the interlayer spacing by intercalating tris(hydroxymethyl) aminomethane (Tris) molecules as supports while introducing high-affinity an ...
... 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 ...
... 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 ...
... 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 ...
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 ...
... 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 ...
... Sulfonated poly(ether ether ketone)-based membranes containing amphoteric functionalized nanofibrous network (SP@f) with the three-dimensional interlaced structure were developed, and the acid-base interaction between SP@f and SPEEK constructs highly conductive proton channel and compatible interfaces. The large specific surface area and aspect ratio of nanofibers afford an orientated ion transmis ...
... 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 ...
... 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 ...
... Fine-tuning the nanochannels of ion conducting membrane is the key to achieving high performance electrochemical devices. Here, we describe an effective way to enhance the membrane performance using heterocyclic imidazole compound as an additive for Nafion. The hygroscopic nature of the imidazole offered sufficient amount of water molecules to the nanochannel of Nafion, affording wider and continu ...
... 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 ...
... The synergistic effects between organic antioxidants with metal ion chelation ability and inorganic radical scavengers were investigated. The different perfluorosulfonic acid (PFSA) composite membranes were prepared by single doping and codoping of alizarin (AZR) and cerium ions. AZR and cerium ion codoping not only significantly enhanced the oxidative stability of the membrane but also lessened b ...
... 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 ...
... In this paper, we report the effect of the annealing process on the hydrogen permeation in/through Pd–Ru membranes. Pd–Ru membranes were deposited via sequential electroless plating method and annealed at different atmospheres and temperatures. The membranes were characterized by XRD, AES, SEM and hydrogen permeation test. The result shows that Ru is amorphous for the as-deposited Pd–Ru membrane. ...
... The chemical composition of two-dimensional transition metal dichalcogenides (TMDs) affects the stacking of the nanosheets and changes the gas separation behavior of the stacked layer; however, this phenomenon has not been discussed in detail so far. In this work, a simple, environmental-friendly aqueous exfoliation of TMDs is applied using tannic acid (TA) for membrane synthesis. To efficiently d ...
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 ...
... Oxygen transport membrane reactors (OTMRs) are used for hydrogen separation through coupling water decomposition reaction (WDR) with hydrogen oxidation reaction (HOR). The activities of catalysts towards WDR and HOR play key roles in the hydrogen separation performance. It is of great practical significance to find suitable catalysts possessing high catalytic activities for WDR and HOR, respective ...
... 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 ...
... The separation of dyes and salts is very challenging in regards to treating high salinity textile wastewater. To effectively dispose dye/salt mixtures, it has become urgent to develop highly permeable and antifouling nanofiltration membranes. Herein, a novel loose nanofiltration membrane was fabricated by combining blending with interfacial polymerisation. Polyvinylidene fluoride (PVDF)/styrene-ma ...
... Highly efficient hydrogen separation membrane is critical in the future hydrogen powered zero carbon society. However, challenges left in searching for hydrogen separation membranes with high permeability, selectivity and easy accessibility. Here, this target was partially achieved by a series of membranes made from in-situ ozone oxidized intrinsic mciroporous polymer membranes (O₃-PIMs) within mi ...
... 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 ...
... Anion exchange membrane fuel cells (AEMFCs) is a potential substitute to the prevailing proton exchange membrane fuel cells (PEMFCs), since non-precious metal catalysts can be applied in the AEMFCs, leading to much lower cost of it. However, anion exchange membranes (AEMs), as a crucial component of the AEMFCs, has always been a challenge in the commercialization of AEMFCs, such as poor life-time ...
... 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 ...