Advanced Membranes for RO Performance

Reverse osmosis membrane with high durability and desalination performance. The membrane has a polyamide layer followed by a zeolite layer on top. The zeolite layer provides protection against chemical degradation of the polyamide layer during desalination. The zeolite layer can be formed by attaching zeolite seeds to the polyamide surface and then growing the zeolite in a solution containing lower concentrations of alkali ions compared to traditional methods. This allows higher zeolite deposition rates and prevents polyamide degradation.

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Composite semipermeable membrane for desalination and water generation with improved performance compared to conventional membranes. The membrane has a unique pleated structure with protrusions in the separation layer. This structure increases the actual thickness of the thin film and surface area of protrusions, allowing higher water flux and salt rejection compared to flat membranes. The protrusions have specific height and angle distributions. The membrane is formed by interfacial polycondensation of polyfunctional amine and acid halide solutions. The compound (I) used in the polycondensation moderates the amine concentration gradient during film formation, leading to protrusion growth and thicker thin films.

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Composite nanofiltration membrane for water treatment with improved selectivity and fouling resistance. The membrane is based on a covalent organic framework complex (COF) called NCOF. The NCOF nanoparticles are dispersed in the polyamide skin layer of the membrane during preparation. This modification enhances the membrane's permselectivity and antifouling properties compared to traditional polyamide nanofiltration membranes. The COF nanoparticles have uniform pore size and hydrophilic groups that improve separation efficiency and prevent fouling.

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Amphiphilic copolymer with improved gas separation performance for polyethylene oxide (PEO)-based membranes. The copolymer has hydrophobic polydimethylsiloxane (PDMS) segments at the ends of the hydrophilic polyethylene glycol (PEG) segments. This copolymer forms micelles that fill the spaces between crystalline PEO spherulites. When mixed with PEO solution, the micelles prevent defects and improve gas separation performance by reducing crystallinity and gaps between PEO spheroids.

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High pressure filtration membranes for applications like reverse osmosis that can withstand high pressures without collapsing. The membranes contain a porous layer made of a specific combination of aromatic sulfone polymer and polyphenylene polymer. The membranes are produced by casting a composition containing the polymers and a solvent, then solidifying it. The membranes can be used to filter fluids like saltwater at high pressures without collapsing due to the unique polymer combination.

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A composite membrane for water treatment that has high efficiency in removing small organic molecules like pollutants while maintaining water flux. The membrane consists of a porous support layer and a dense separation layer. The support layer is made of hollow fiber ultrafiltration membrane. The separation layer is coated onto the support layer using a crosslinking agent. The crosslinking agent contains nanocellulose to strengthen the separation layer. Heat treatment crosslinks the nanocellulose to create a stable composite membrane. The composite membrane shows high rejection of small organic compounds like Congo red, methyl blue, bisphenol A, floxacin, indomethacin, and diclofenac while maintaining good water flux.

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Preparing a highly gas-permeable organic-inorganic composite fiber gas separation membrane by electrospinning a composite fiber mat of metal-organic framework (MOF) particles in a polymer solution, followed by in-situ polymerization of a low molecular weight polymer like PEG in the interstices of the electrospun fibers to construct a dense composite fiber membrane. The MOFs provide micropores for gas sieving and the polymer provides high gas permeability. The composite fiber membrane has significantly higher CO2 permeability and selectivity compared to traditional polymer membranes.

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A thin, low-pressure reverse osmosis membrane for domestic water treatment that balances salt removal and water yield. The membrane consists of three layers: a high-density polyethylene porous support, a polysulfone ultrafiltration layer, and a thin cross-linked aromatic polyamide reverse osmosis layer. The composite membrane is formed by heat sealing the ultrafiltration layer onto the support, then coating the reverse osmosis layer on top. The membrane thickness is less than 150 microns. This design enables high salt rejection and water yield for domestic applications.

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A composite reverse osmosis membrane with improved fouling resistance for desalination applications. The membrane has a porous support layer, a separation functional layer containing polyamide, and a coating layer. The coating layer has a low water contact angle (40° or less) and low protein adsorption force (0.4 nN or less). This coating configuration reduces fouling compared to conventional membranes, allowing stable long-term desalination performance.

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Composite membrane for gas and liquid separation that overcomes the limitations of using pure MOF nanosheet membranes due to poor mechanical strength and lack of controllable selectivity. The composite membrane is made by stacking thin MOF nanosheets between layers of a self-supporting polyamide nanofiltration membrane. This sandwich structure provides mechanical strength while maintaining the separation properties of the MOF nanosheets. It allows high transmembrane pressures and adjustable selectivity compared to pure MOF nanosheet membranes. The composite membrane is prepared by alternately casting and drying layers of the MOF nanosheets and polyamide solution.

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Reverse osmosis membrane for water filtration with improved salt and organic rejection. The membrane has a support layer followed by an active layer containing a silicone additive and a fluorine-based additive. The added silicone and fluorine reduce surface tension of the aqueous solution during membrane formation, improving wetting and adhesion to the support layer. This improves salt rejection compared to conventional membranes. The membrane also has good organic rejection, with IPA removal rates of 94-95% under test conditions.

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Composite nanofiltration membrane with environmental responsiveness that can dynamically adjust its permeability in response to environmental conditions. The membrane has a porous support layer, an intermediate layer of environmentally responsive nanoparticles, and a separation surface layer. The nanoparticle layer controls the polymerization process to reduce thickness and increase surface roughness, improving permeability. The nanoparticles also change size under environmental stimuli to introduce additional nanochannels, enhancing permeability without affecting selectivity.

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A novel reverse osmosis membrane for desalination with improved performance, cost, and longevity compared to conventional membranes. The membrane is made of multiple layers stacked together. The inner layers are conventional reverse osmosis membranes made of polymers. The outer layers are carbon fiber grid membranes. Soaking the composite membrane in a sodium bisulfite solution for 2-6 hours improves performance. The carbon fiber grid membranes provide mechanical strength and support while allowing water flow through the polymer layers. This structure reduces thickness, improves desalination rate, and extends membrane life compared to single-layer membranes.

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Preparing a gas separation membrane with improved mechanical strength and CO2 separation performance by using electrospun nanofibers as a skeleton that is filled with light-curable polyethylene glycol (PEG) polymers. The nanofibers provide reinforcement to the membrane and the PEG polymers fill the nanofiber pores. The membrane is prepared by electrospinning nanofibers, filling them with PEG, and then curing the PEG with UV light. The resulting membrane has a compact, defect-free structure with enhanced mechanical properties and CO2 separation performance compared to traditional PEG membranes.

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A self-assembled polymer nanoparticle reinforced separation membrane that improves permeability, rejection, and pollution resistance compared to traditional nanoparticle-enhanced membranes. The membrane is prepared by in-situ self-assembly of polymer nanoparticles during membrane formation. The nanoparticles are made of sulfonated polyetheretherketone (SPEEK) and branched polyethyleneimine (BPEI) that self-assemble in solution. This enables stable nanoparticle dispersions over a wide pH range, avoiding particle leakage. The nanoparticles enhance membrane properties like pore structure and hydrophilicity, without compromising rejection. The membrane can have SPEEK content of 0.17-0.68 wt%, BPEI of 0.17-0.68 wt

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Wide-runner reverse osmosis membrane for desalination with improved anti-fouling properties and higher water recovery. The membrane has a wide flow channel on the dense water side to slow pollutant accumulation and reduce fouling. The channel has separate first and second flow paths. The wider channel improves water quality by reducing fouling and allowing higher water recovery compared to standard reverse osmosis membranes. The wider channel is achieved by thickening the dense water layer in that area. The membrane also has a central core tube with permeation holes for water flow. This allows concentrated water to be separated and guided out separately from the product water. The wider flow channel, core tube, and permeation holes improve membrane performance and fouling resistance compared to standard reverse osmosis membranes.

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Highly durable reverse osmosis membrane for water desalination with improved cleaning and long life compared to conventional membranes. The membrane has optimized bonding between the support layer and the selective layer to prevent peeling during cleaning and operation. The bonding force is 20-1100gf. This reduces durability loss during cleaning while maintaining salt rejection. The membrane also has specific polymer compositions and solvent ratios. The sequential layers are a porous support, polymer support, and hydrophilic selective layer. The selective layer has amine functional groups and halogen compounds for interfacial polymerization.

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Polyimide/surface-modified metal organic framework mixed matrix membrane for CO2 separation with improved performance compared to existing mixed matrix membranes. The membrane is prepared by modifying the metal organic framework (MOF) particles with dopamine to prevent agglomeration and increase compatibility with the polyimide matrix. The surface modification reduces non-selective voids at the interface between the MOF and polyimide phases. The modified MOF-doped polyimide membrane has higher CO2 permeability and selectivity compared to the unmodified MOF membrane, exceeding the Robeson upper limit for CO2/N2 and CO2/CH4 separation.

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Hybrid membranes containing nanoparticles with a zeolite imidazolate structure dispersed in a polymer matrix. The nanoparticles have controlled crystal structure and bonding strength due to the use of alkylamine ligands. This provides improved gas separation performance compared to pure zeolite membranes. The nanoparticles have small sizes (100 nm or less) with pores of 0.1-1 nm. The hybrid membranes separate gases like C3H6/C3H8, CO2/CH4, N2/CH4, etc.

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Forward osmosis membrane with high water permeation volume and reduced solute concentration polarization for efficient forward osmosis treatment. The membrane has a thin semi-permeable membrane layer on a porous polyketone support layer. The support layer is made of polyketone with large pores to minimize solute buildup. This allows more water to permeate through the membrane. The thin membrane exhibits semi-permeable behavior. The large pore size of the support layer reduces interior concentration polarization. This improves membrane performance for forward osmosis applications.

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Reverse osmosis membrane for osmotic backwashing that can maintain membrane performance and lifespan after backwashing. The membrane has a unique structure with a sulfonated polysulfone-based polymer compound in the first support layer. This prevents peeling during high-pressure backwashing compared to conventional membranes. The sulfonated polymer improves bonding between the support and membrane layers. It also reduces fouling and improves salt rejection. The membrane is made by treating a sulfonated polymer solution on the support first, then a second polymer solution.

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Composite membrane with high organic solvent rejection and reasonable permeation flux for nanofiltration applications. The membrane has a bulk phase of zeolite particles interpenetrated by a binding carbonaceous phase. The zeolite phase forms a continuous structure with micron-scale voids between zeolite clusters. This allows high solvent flow through the zeolite pores and micron voids while preventing solvent bypass through the binding phase. The composite membrane has advantages over traditional zeolite or mixed matrix membranes for separating organic molecules from solvents due to its optimized zeolite-carbon structure and high zeolite content.

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A reverse osmosis membrane for water purification applications that provides high rejection of impurities while maintaining high water permeability at low pressures. The membrane consists of a polymer microporous support layer and a thin polyamide separation layer directly coated onto the support. The support is made of a polymer microporous membrane. The polyamide layer is formed by interfacial polymerization of an amine and acid halide solution on the support. The membrane has a thickness of 5-150 μm, rejection of 60% or more at 1.0 MPa, and water permeability of 2.0 L/m^2/hr or more.

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Preparing ultra-thin composite membranes with adjustable gas separation performance by layer-by-layer assembly of covalent organic framework (COF) nanosheets and graphene oxide (GO) nanosheets. The method involves using vacuum filtration at elevated temperatures to change the overlap of the layers. This allows preparing dense, continuous membranes with small pore sizes for improved gas separation. The composite membrane made of COF (CTF-BTD) and GO has high gas separation selectivity for hydrogen over carbon dioxide and nitrogen due to the small COF pore size.

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Highly durable and anti-fouling reverse osmosis membranes for water purification systems that have extended life and resistance to fouling. The membranes have a specialized desalination layer made of fragrant polyamides. The fragrant polyamides contain compounds like furfuryl alcohol, trihydroxyethyl isocyanates, and m-phenylene diamine. This layer improves membrane fouling resistance and longevity compared to traditional reverse osmosis membranes.

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Molecularly-mixed composite membranes for improved separation performance and scalability compared to traditional membranes. The membranes are made by dispersing an amorphous scrambled porous organic cage (ASPOC) material into a polymer matrix without aggregation. The ASPOC cages have weak cage-cage interactions and strong polymer-cage interactions to form a homogeneous membrane. This reduces defects from particle aggregation compared to adding filler particles. The membranes have increased separation properties and anti-plasticizing effects. The ASPOC material is made by synthesizing it separately then mixing it with the polymer and solvent for casting.

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Composition for forming a protective layer on reverse osmosis membranes that improves salt rejection and boron removal while maintaining high flow rates. The composition contains a specific polymer with a weight average molecular weight of 500,000 to 700,000. This polymer forms a protective layer on the membrane surface to prevent fouling and contamination. The protective layer thickness is 100-300 nm. The composition can also include a hydrophilic polymer, crosslinking agent, and water.

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High-performance reverse osmosis membrane for desalination that improves both flow rate and salt rejection compared to conventional membranes. The membrane structure includes a porous support layer with carbon nanotubes and a polyamide layer on top. The carbon nanotubes in the support layer enhance its properties. The membrane is made by doping a polymer solution with carbon nanotubes to form the support layer, then coating and polymerizing an amine solution followed by an acid halide solution to form the polyamide layer. This improves the flow rate and salt rejection compared to just the polyamide layer.

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Water treatment membrane with improved permeation flux for applications like reverse osmosis. The membrane is made by forming a polyamide active layer on a porous support using interfacial polymerization of an aqueous solution containing an amine and an organic solution containing an acyl halide. The aqueous solution contains a flux enhancer with at least 3 acetic acid groups. This enhancer improves the permeate flow rate compared to conventional amine-acid combinations. The membrane can be used in water treatment modules for processes like desalination.

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Reverse osmosis membrane with improved fouling resistance for high concentration feeds like seawater. The membrane composition is a composite with a polyamide selective layer on a support. The polyamide layer has a unique surface chemistry that prevents fouling by organic and inorganic contaminants. The fouling resistance is achieved without needing pre-treatment or coating steps. The composition involves a specific polyfunctional amine and polyfunctional acyl halide used in the interfacial polymerization to form the polyamide layer. This chemistry provides a surface with enhanced fouling resistance compared to conventional polyamide membranes.

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Organic solvent nanofiltration membrane with high flux and high rejection for organic solvents using molybdenum disulfide as the active layer. The membrane is prepared by dopamine modification of a base membrane followed by vacuum filtration of molybdenum disulfide nanosheets at low speed to self-assemble into a thin layer on the base. The resulting composite membrane has improved organic solvent flux compared to other materials while maintaining high rejection of solutes like dyes.

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Organic solvent nanofiltration (OSN) membrane for separating organic solvents with high flux and rejection. The OSN membrane is prepared by spin-coating an aqueous solution onto an organic microfiltration (OMF) membrane, followed by interfacial polymerization and drying. This method allows preparing OSN membranes with ultra-thin defect-free layers on OMF bases, improving flux compared to traditional OSN membranes. The resulting OSN/OMF composite membrane has high solvent flux and solute rejection for separating organic solvents.

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A polymer/polymer hollow microsphere hybrid membrane with improved separation performance compared to conventional dense polymer membranes. The hybrid membrane has a continuous polymer matrix containing dispersed hollow polymer microspheres. The microspheres have a selective sieving ability due to their hollow structure, while the continuous polymer matrix provides mechanical strength. This hybrid membrane design allows higher separation selectivity and permeability compared to dense polymer membranes without sacrificing mechanical properties. It also avoids the interface defects and voids associated with inorganic-organic hybrid membranes.

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Hollow fiber gas separation membrane made from a polyimide polymer and a metal organic framework (MOF) material called MIL-101. The membrane has improved gas separation properties compared to pure polyimide due to the addition of the MOF particles. The MOF accounts for 2-10 mass% of the membrane. The MOF enhances gas permeability while maintaining good selectivity. The composite membrane is prepared by blending the polyimide and MOF solutions to make the hollow fiber membrane. The MOF particles are dispersed in the polyimide matrix.

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Cross-linked acid functionalized hollow nanogels embedded in a polymer matrix to create high-performance gas separation membranes. The nanogels have a hollow structure that allows them to absorb a lot of water. Cross-linking the nanogels with acid functional groups enhances their interaction with gases like CO2. When these acid functionalized nanogels are embedded in a polymer matrix, they significantly improve gas separation performance compared to the polymer alone. The nanogels increase the water content of the matrix, which strengthens gas diffusion through the membrane. The acid functional groups also increase affinity for specific gases like CO2.

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A reverse osmosis membrane with improved water purification performance and durability. The membrane has a polysulfone layer with controlled pore distribution, size, and density. The polysulfone layer is formed using a mixed solvent with two solvents having different solubility parameters. This adjusts the outflow rates of the solvents during membrane formation to create the desired pore characteristics. The result is a membrane with reduced large pores (<0.5% over 40 nm), high initial flux, and superior salt rejection compared to conventional membranes.

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Hollow fiber reverse osmosis membrane with high water permeability and removal performance at low operating costs for treating water with low salt concentrations. The membrane has a cellulose acetate structure with specific properties. The hollow fiber diameter is 50-200 µm, outer diameter is 100-280 µm, length is 15-500 cm, inner diameter is 75-190 µm, outer surface has a dense layer 0.1-7 µm thick, pressure resistance is 0.02-0.08, salt removal rate is 90-99%, and hydrothermal treatment is at 50-70°C. The membrane balances water permeability and salt removal at low pressures for applications like wastewater treatment, brine, sewage, industrial waste

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A method for producing polyamide reverse osmosis membranes with high salt rejection and flux. The method involves coating a microporous support with a polyfunctional amine solution containing benzoic acid or derivatives at 0.01-9.9 wt%. This modification enhances salt rejection while maintaining high flux compared to traditional polyamide membranes.

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Preparing reverse osmosis membranes with improved flux performance by treating the membrane with ammonium salts. The ammonium salt processing involves exposing the reverse osmosis membrane to an aqueous solution containing the ammonium salt. The ammonium salt used has specific cations like tri methyl benzyl ammonium, dibutyl ammonium, tripropyl ammonium, etc. and suitable anions like chloride or borate. The treated membrane has improved flux through it compared to untreated membranes. The flux improvement allows higher water flow rates through the membrane at lower pressures.

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Extreme low-pressure reverse osmosis membrane with high salt rejection and flux for desalination at pressures as low as 40 psi (270 kPa). The membrane has a composite structure with an active layer containing m-phenylene diamine (MPD) and p-phenylenediamine (PPD) polymers. The membrane can remove over 98.5% of salt ions at 60 psi and has a water flux of over 1.1 m/day. The low-pressure capability and high salt rejection makes it suitable for desalination applications with minimal energy requirements. The membrane is produced by a method involving forming a polyamide active layer on a support by polymerization of MPD and PPD in the presence of an initiator and a solvent.

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Reverse osmosis membrane with improved stability and fouling tolerance for water desalination. The membrane has a specific surface area of 2-1000 in the separation layer or coating on the surface. This reduces fouling compared to high surface area membranes. The coating can be a neutral organic substance or polymer with hydrophilic groups. This neutralizes the membrane charge and prevents fouling substances from sticking. The membrane allows high salt rejection, water flux, and stability during fouling conditions.

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Reverse osmosis composite membrane for desalination and water purification that can withstand high pressures without compromising performance. The membrane design prevents issues like membrane deformation, compaction, and reduced flow under high pressure. The support film structure is optimized to prevent consolidation and closure of flow channels. This allows consistent water quality and flow rates at high pressures. It also enables seamless switching between high and low pressure operations without loss of performance compared to low pressure.

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Composite reverse osmosis membrane for treating high concentration solutions that can operate at high pressures like 70 kgf/cm2 without degradation. The membrane has a consolidated porous support layer with high compaction force and thickness, like 10 kgf/cm2 and 5 um, that can withstand high pressures. A thin film layer is formed on top of the consolidated support. The consolidation prevents pore blockage at high pressures while the thin film provides the rejection performance.

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Composite reverse osmosis membrane that provides high salt rejection, high water permeability, and pressure resistance without consolidation under high pressure conditions. The membrane uses a dense porous support layer instead of the typical porous support with large pores. The dense support layer, made by densifying an ultrafiltration membrane, has higher salt blocking ability compared to the large pore membranes. This dense support allows the composite membrane to maintain performance and stability when operated at high pressures without consolidation like large pore membranes do.

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High-performance composite reverse osmosis membranes with improved salt rejection, water permeability, and pressure resistance compared to conventional composite RO membranes. The key innovation is a porous support membrane with a dense skin layer on the surface and a sparse interior structure. This allows forming a tight skin layer without consolidating the rest of the support. The composite RO membrane with this support has high salt rejection, water permeability, and pressure resistance.

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A high-pressure reverse osmosis membrane that can operate at pressures above 70 atm without significant degradation in separation performance. The membrane has a thin separation layer sandwiched between two support layers. The outer support layer has larger pores than the inner support layer. This configuration allows high-pressure operation without membrane failure or significant performance loss. The thin separation layer reduces defects and prevents membrane densification at high pressures. The support layers provide structural integrity.

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A composite membrane for high pressure separation applications like seawater desalination that can withstand high pressures without degrading performance. The composite membrane has a thin separation layer sandwiched between thicker support layers. The separation layer has smaller pores than the outer layers. This configuration prevents the separation layer from densifying or tearing at high pressures like thicker layers would. The thin separation layer maintains good separation properties at high pressures.

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Membrane with a thin defective separation layer covered by a soluble protective layer. The protective layer corrects the imperfections of the thin separation layer. It has a higher permeate flow and lower selectivity compared to the separation layer. The protective layer is soluble in a solvent and can be applied by solution coating. The solvent is then recovered leaving a homogeneous protective layer. This soluble protective layer reduces defects in the separation layer and improves membrane performance for separating mixtures like pertraction, pervaporation, and condensable gas separation. The protective layer can be crosslinked to improve stability.

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Reverse osmosis membrane with improved performance for desalination, fouling tolerance, and chlorine resistance. The membrane has a thin film with anionic hydrophilic groups on the surface of the separation layer. This film is made by coating the layer with a solution of a polymer with anionic hydrophilic groups, like sulfonated polysulfone, and then vaporizing the solvent to leave behind the film. The anionic groups improve salt rejection, fouling tolerance, and chlorine tolerance compared to traditional reverse osmosis membranes.

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