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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