Abstract: The invention relates to a specific apparatus, more particularly a chain of gas separation membrane modules, for separation of gas mixtures into two fractions each of elevated purity.

Abstract: The present invention provides an air-conditioning system that supplies a gas to a space to be air-conditioned and/or discharges a gas from the space to be air-conditioned through a permeable membrane in order to provide an air-conditioning system that can sufficiently block suspended matter in the air such as SPM, and can sufficiently introduce outside air in which the permeable membrane is an asymmetric membrane formed of a polymeric material prepared by polymerizing a monomer composition containing a predetermined monomer.

Abstract: A permselective material has a polymer having an organosiloxane skeleton and containing a dispersed solid additive. When oxygen and nitrogen are passed through a membrane having the permselective material, the relation between the permeability coefficients [cm3·cm·sec?1·cm?2·cmHg?1] of oxygen and nitrogen at a temperature of 23±2° C. under a pressure difference of 1.05 atm to 1.20 atm through the membrane is expressed by Formula (1): 0.94 ? P ? ( O 2 ) P ? ( N 2 ) < 1 ( 1 ) where P(O2) denotes the permeability coefficient of oxygen, while P(N2) denotes the permeability coefficient of nitrogen.

Abstract: A composition of and a method of making high performance crosslinked membranes are described. The membranes have a high resistance to plasticization by use of crosslinking. The preferred polymer material for the membrane is a polyimide polymer comprising covalently bonded ester crosslinks. The resultant membrane exhibits a high permeability of CO2 in combination with a high CO2/CH4selectivity. Another embodiment provides a method of making the membrane from a monesterified polymer followed by final crosslinking after the membrane is formed.

Abstract: Disclosed are a gas separation membrane and a gas separation method in which at least one species of organic vapor is separated and recovered from an organic vapor mixture using the gas separation membrane. The gas separation membrane is made of an aromatic polyimide composed of a tetracarboxylic acid component consisting of an aromatic ring-containing tetracarboxylic acid and a diamine component comprising 10 to 90 mol % of a combination of (B1) 3,4?-diaminodiphenyl ether and (B2) 4,4?-diaminodiphenyl ether at a B1 to B2 molar ratio, B1/B2, ranging from 10/1 to 1/10, and 10 to 90 mol % of other aromatic diamine.

Abstract: In one aspect, the present invention provides a curable composition useful in the preparation of a gas separation membrane. The curable composition comprises a polyvinyl alcohol; an aliphatic polyamine; a polyglycidyl ether; and a salt of a C2 to C4 heterocyclic amino acid. In another aspect the present invention provides a composition comprising a crosslinked polyvinyl alcohol comprising structural units derived from a polyglycidyl ether, a polyamine and the salt of a C2 to C4 heterocyclic amino acid. The compositions are useful in the preparation of gas separation membranes in which the C2 to C4 heterocyclic amino acid in the form of its salt functions as a mobile carrier of carbon dioxide.

Abstract: The present invention discloses a new type of polyimide membranes including hollow fiber and flat sheet membranes with high permeances for air separations and a method of making these membranes. The new polyimide hollow fiber membranes have O2 permeance higher than 300 GPU and O2/N2 selectivity higher than 3 at 60° C. under 308 kPa for O2/N2 separation. The new polyimide hollow fiber membranes also have CO2 permeance higher than 1000 GPU and single-gas selectivity for CO2/CH4 higher than 20 at 50° C. under 791 kPa for CO2/CH4 separation.

Abstract: The present disclosure relates to a high molecular weight, monoesterified polyimide polymer. Such high molecular weight, monoesterified polyimide polymers are useful in forming crosslinked polymer membranes for the separation of fluid mixtures. According to its broadest aspect, the method of making a crosslinked membrane comprises the following steps: (a) preparing a polyimide polymer comprising carboxylic acid functional groups from a reaction solution comprising monomers and at least one solvent; (b) treating the polyimide polymer with a diol at esterification conditions in the presence of dehydrating conditions to form a monoesterified polyimide polymer; and (c) subjecting the monoesterified fiber to transesterification conditions to form a crosslinked fiber membrane, wherein the dehydrating conditions at least partially remove water produced during step (b). The crosslinked membranes can be used to separate at least one component from a feed stream including more than one component.

Abstract: The present invention involves the use of a multi-stage membrane system for gas, vapor, and liquid separations. In this multi-stage membrane system, high selectivity and high permeance or at least high selectivity polybenzoxazole membranes or cross-linked polybenzoxazole membranes are applied for a pre-membrane or both the pre-membrane and the secondary membrane. A primary membrane can be from conventional glassy polymers. This multi-stage membrane system can reduce inter-stage compression cost, increase product recovery and product purity for gas, vapor, and liquid separations. It can also save the cost compared to the system using all the high cost polybenzoxazole membranes or cross-linked polybenzoxazole membranes.

Abstract: The invention relates to a method for producing membrane, in particular gas separation membrane, wherein the membrane comprises a selective separating layer. The following steps are carried out: a) a polymer solution is produced from at least one polymer and at least one polyglycol ether, b) the polymer solution is cast into a film, c) in a further step, the selective separating layer is produced from the film, preferably by drying. The invention, among other things, further relates to a membrane, in particular gas separation membrane, comprising a selective separating layer.

Abstract: A polymer membrane, based on a facilitated transport mechanism, for separating olefins from paraffins, and a method for fabricating is provided. In the polymer membrane for facilitated transport, silver nanoparticles are partially cationized and play a role as a carrier for transporting olefins across the membrane, with p-benzoquinone serving as an electron acceptor.

Abstract: The invention relates to polymeric ultrafiltration or microfiltration membranes of, for instance, poly(ethylene chlorotrifluoroethylene) (HALAR®), PVDF or PP, incorporating PVME or vinyl methyl ether monomers. The PVME may be present as a coating on the membrane or dispersed throughout the membrane or both. The membranes are preferably hydrophilic with a highly asymmetric structure with a reduced pore size and/or absence of macrovoids as a result of the addition of PVME. The PVME maybe cross-linked. The invention also relates to methods of hydrophilising membranes and/or preparing hydrophilic membranes via thermal or diffusion induced phase separation processed.

Abstract: The present invention discloses a new type of high performance polymer membranes prepared from aromatic polyimide membranes by thermal treating and crosslinking and methods for making and using these membranes. The polymer membranes were prepared from aromatic polyimide membranes by thermal treating under inert atmosphere followed by crosslinking preferably by using a UV radiation source. The aromatic polyimide membranes were made from aromatic polyimide polymers comprising both pendent hydroxy functional groups ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone. The membranes showed significantly improved selectivity and permeability for gas separations compared to the aromatic polyimide membranes without any treatment. The membranes can be fabricated into any convenient geometry and are not only suitable for a variety of liquid, gas, and vapor separations, but also can be used for other applications such as for catalysis and fuel cell applications.

Abstract: The present invention involves the use of a multi-stage membrane system for gas, vapor, and liquid separations. In this multi-stage membrane system, high selectivity and high permeance or at least high selectivity polybenzoxazole membranes or cross-linked polybenzoxazole membranes are applied for a pre-membrane or both the pre-membrane and the secondary membrane. A primary membrane can be from conventional glassy polymers. This multi-stage membrane system can reduce inter-stage compression cost, increase product recovery and product purity for gas, vapor, and liquid separations. It can also save the cost compared to the system using all the high cost polybenzoxazole membranes or cross-linked polybenzoxazole membranes.

Abstract: Problem to be Solved: To provide a gas separation membrane having an excellent performance balance (balance between gas permeation performance and gas separation ability) as a gas separation membrane. Solution: A gas separation membrane comprising a porous support member and a gas separating resin layer formed on the porous support member, wherein the porous support member has a mode diameter as measured by a mercury porosimeter of from 0.005 ?m to 0.3 ?m, and a pore size distribution index as measured by the mercury porosimeter of from 1 to 15.

Abstract: Disclosed herein are processes for producing a CO2-depleted product gas stream. The processes involve feeding a natural gas feed stream comprising greater than about 10 vol % CO2 to at least one membrane unit comprising a plurality of polymer membranes to provide a CO2-rich permeate comprising at least 95 vol % CO2 and a CO2-depleted product gas stream. The polymer membranes comprise a crosslinked polyimide polymer having covalent ester crosslinks and have a CO2 permeance of at least 20 GPU and a CO2/CH4 selectivity of greater than 20, at 35 degrees C. and a feed pressure of 100 psia. Also disclosed herein is an apparatus incorporating the crosslinked polyimide polymer for producing a CO2-depleted product gas stream from a natural gas feed stream.

Abstract: A process for forming a porous nanoscale membrane is described. The process involves applying a nanoscale film to one side of a substrate, where the nanoscale film includes a semiconductor material; masking an opposite side of the substrate; etching the substrate, beginning from the masked opposite side of the substrate and continuing until a passage is formed through the substrate, thereby exposing the film on both sides thereof to form a membrane; and then simultaneously forming a plurality of randomly spaced pores in the membrane. The resulting porous nanoscale membranes, characterized by substantially smooth surfaces, high pore densities, and high aspect ratio dimensions, can be used in filtration devices, microfluidic devices, fuel cell membranes, and as electron microscopy substrates.

Abstract: The present invention relates to compositions for producing membranes, the compositions comprising at least 0.1% by weight of highly branched polymer, at least 0.5% by weight of linear polymer and at least 30% by weight of solvent. The present invention additionally describes membranes obtainable from the compositions, and methods of producing these membranes.

Abstract: Disclosed is a hollow fiber that includes a hollow positioned at the center of the hollow fiber, macropores positioned at adjacent to the hollow, and mesopores and picopores positioned at adjacent to macropores, and the picopores are three dimensionally connected to each other to form a three dimensional network structure. The hollow fiber includes a polymer derived from polyamic acid, and the polyamic acid includes a repeating unit obtained from aromatic diamine including at least one ortho-positioned functional group with respect to an amine group and dianhydride.

Abstract: In the present invention high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes and methods for making and using these membranes have been developed. The cross-linked polybenzoxazole and polybenzothiazole polymer membranes are prepared by: 1) first synthesizing polyimide polymers comprising pendent functional groups (e.g., —OH or —SH) ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone; 2) fabricating polyimide membranes from these polymers; 3) converting the polyimide membranes to polybenzoxazole or polybenzothiazole membranes by heating under inert atmosphere such as nitrogen or vacuum; and 4) finally converting the membranes to high performance cross-linked polybenzoxazole or polybenzothiazole membranes by a crosslinking treatment, preferably UV radiation. The membranes can be fabricated into any convenient geometry.

Abstract: In the present invention high performance cross-linked polybenzoxazole and polybenzothiazole polymer membranes and methods for making and using these membranes have been developed. The cross-linked polybenzoxazole and polybenzothiazole polymer membranes are prepared by: 1) first synthesizing polyimide polymers comprising pendent functional groups (e.g., —OH or —SH) ortho to the heterocyclic imide nitrogen and cross-linkable functional groups in the polymer backbone; 2) fabricating polyimide membranes from these polymers; 3) converting the polyimide membranes to polybenzoxazole or polybenzothiazole membranes by heating under inert atmosphere such as nitrogen or vacuum; and 4) finally converting the membranes to high performance cross-linked polybenzoxazole or polybenzothiazole membranes by a crosslinking treatment, preferably UV radiation. The membranes can be fabricated into any convenient geometry.

Abstract: This abstract discusses membranes needed to separate fluids for the production of oxygen-enriched air, nitrogen-enriched-air, for the separation of carbon dioxide from hydrocarbons, and the separation of hydrogen from various petrochemical and oil refining streams. Membranes are needed that provide a resistance to interaction with process components or contaminants, provide the mechanical strength required to withstand high membrane differential pressures and high process temperatures, and exhibit sufficient maximum strain such that membranes are not brittle and can easily be formed into desirable membrane forms. Membranes of polyimide polymers, particularly polyimide polymers sold under the trade name P-84, are annealed in a controlled annealing step to improve the mechanical properties of the polymers used to make separation membranes.

Abstract: The present invention discloses a new process of treating natural gas using high gas permeability polybenzoxazole polymer membranes operated at high temperatures that can provide sufficient dew point margin for the product gas. The high gas permeability polybenzoxazole polymer membranes can be used for a single stage membrane system or for the first stage membrane in a two stage membrane system for natural gas upgrading. Simulation study has demonstrated that a costly membrane pretreatment system such as a MemGuard™ system will not be required in the present new process. The new process can achieve significant capital cost saving and reduce the existing membrane footprint greater than 50%.

Abstract: The present disclosure relates to a high molecular weight, monoesterified polyimide polymer. Such high molecular weight, monoesterified polyimide polymers are useful in forming crosslinked polymer membranes for the separation of fluid mixtures. According to its broadest aspect, the method of making a crosslinked membrane comprises the following steps: (a) preparing a polyimide polymer comprising carboxylic acid functional groups from a reaction solution comprising monomers and at least one solvent; (b) treating the polyimide polymer with a diol at esterification conditions in the presence of dehydrating conditions to form a monoesterified polyimide polymer; and (c) subjecting the monoesterified fiber to transesterification conditions to form a crosslinked fiber membrane, wherein the dehydrating conditions at least partially remove water produced during step (b). The crosslinked membranes can be used to separate at least one component from a feed stream including more than one component.

Abstract: The invention relates to polymeric ultrafiltration or microfiltration membranes of, for instance, Halar, PVDF or PP, incorporating PVME or vinyl methyl ether monomers. The PVME may be present as a coating on the membrane or dispersed throughout the membrane or both. The membranes are preferably hydrophilic with a highly asymmetric structure with a reduced pore size and/or absence of macrovoids as a result of the addition of PVME. The PVME maybe cross-linked. The invention also relates to methods of hydrophilising membranes and/or preparing hydrophilic membranes via thermal or diffusion induced phase separation processed.

Abstract: The present invention discloses a new type of high performance mixed matrix membranes (MMMs) and methods for making and using the same. The MMMs comprise a continuous polymer matrix and at least two types of molecular sieves dispersed therein. The continuous polymer matrix in the MMM contains at least one type of polymer. The MMM in the form of a dense film, asymmetric flat sheet membrane or otherwise prepared exhibits simultaneously improved selectivity and permeability for gas separations compared to polymer membranes made from a continuous polymer matrix without any molecular sieves or with only one type of molecular sieve. MMMs of the present invention are suitable for a wide range of gas, vapor, and liquid separations such as alcohol/water, CO2/CH4, H2/CH4, O2/N2, CO2/N2, olefin/paraffin, iso/normal paraffins, and other light gases separations.

Abstract: An apparatus for separating at least one component from a mixture of a plurality of chemical species is provided. The apparatus comprises a membrane structure comprising a plurality of pores disposed within a matrix material to allow mass transport from a first surface of the membrane structure to a second surface of the membrane structure. The matrix material has a thermal conductivity of at least about 10 W/m/K; and a functional material disposed within at least a portion of the plurality of pores. The functional material has the property of promoting selective transport of at least one species through the membrane structure from the first surface to the second surface.

Abstract: There is disclosed an asymmetric gas separation membrane exhibiting both improved gas separation performance and improved mechanical properties, which is made of a soluble aromatic polyimide comprised of a repeating unit represented by general formula (1): wherein B in general formula (1) B comprises 10 to 70 mol % of tetravalent unit B1 represented by general formula (B1) and 90 to 30 mol % of tetravalent unit B2 represented by general formula (B2), and A in general formula (1) comprises 10 to 50 mol % of bivalent unit A1 represented by general formula (A1a) or the like and 90 to 30 mol % of bivalent unit A2 represented by general formula (A2a) or the like.

Abstract: A gas separation membrane comprises a blend of polyethersulfone (PES) and aromatic polyimide polymers that may comprise a plurality of first repeating units of formula (I), wherein X1, X 2 and X3 are herein defined.

Abstract: Processes for dehydrating an organic/water solution by pervaporation or vapor separation using fluorinated membranes. The processes are particularly useful for treating mixtures containing light organic components, such as ethanol, isopropanol or acetic acid.

Abstract: The present invention discloses a novel method of making high performance mixed matrix membranes (MMMs) using stabilized concentrated suspensions of solvents, uniformly dispersed polymer stabilized molecular sieves, and at least two different types of polymers as the continuous blend polymer matrix. MMMs as dense films or asymmetric flat sheet or hollow fiber membranes fabricated by the method described in the current invention exhibit significantly enhanced permeation performance for separations over the polymer membranes made from the continuous blend polymer matrix. MMMs of the present invention are suitable for a wide range of gas, vapor, and liquid separations such as alcohol/water, CO2/CH4, H2/CH4, O2/N2, CO2/N2, olefin/paraffin, iso/normal paraffins, and other light gases separations.

Abstract: A composition includes a first polymer having monomers each containing an imidazole group, and a second polymer, the first and second polymers being a polymer blend. The first polymer, the second polymer, or both may be cross-linked. The carbonized composition, polymeric and carbon membranes (either in the form of a flat sheet or a hollow fiber) made from the composition are also described.

Abstract: A membrane for gas separation includes a porous support layer and a separation layer. The separation layer comprises a mixture of one or more saccharide derivatives and one or more homopolymers. The saccharide derivative(s) may have a cyclic structure with five or six ring atoms, or a linear structure, or may include monosaccharide derivatives which are bound via glycoside bonds, and the number of monosaccharides bound in this manner may be 2 to 1,000. A membrane can be produced by preparing a homogeneous solution which comprises a saccharide derivative and a homopolymer in a solvent; and pouring the homogenous solution onto a support layer. The membrane may be used in a gas separation module the operation of which makes use of the membrane.

Abstract: Various embodiments of the present invention are directed to limiting a presence of air bubbles in fluidic media in a reservoir. Air passages may allow air to escape from fluidic media in a reservoir. Membranes may allow for trapping air bubbles in fluidic media before fluidic media enters a reservoir. A membrane may allow air to flow from a first reservoir containing fluidic media to a second reservoir while plunger heads within each of the reservoirs are moved within the reservoirs. An inner reservoir with a membrane may be moveable within an outer reservoir to allow air to move from the outer reservoir to the inner reservoir. An inner reservoir containing pressurized gas may allow fluidic media to be transferred to an outer reservoir.

Abstract: The present invention relates to methods and apparatuses for water filtration comprising contacting a water stream with a membrane comprising a polysulfone having structural units of Formula I wherein X is OH, NR1R2, or OR3; R1 and R2 are independently at each occurrence hydrogen, a C1-C5000 aliphatic radical, a C3-C12 cycloaliphatic radical, a C3-C12 aromatic radical, a polypeptide, a combination thereof, or R1 and R2 taken together form a 5- or 6-membered aliphatic ring or a 5-membered aromatic ring; R3 is a C1-C20 aliphatic radical, C3-C12 cycloaliphatic radical, C3-C12 aromatic radical, or a combination thereof; B? and C? are independently at each occurrence a nitro group, C1-C20 aliphatic radical, C3-C12 cycloaliphatic radical, C3-C12 aromatic radical, or a combination thereof; and q and r are independently at each occurrence 0 to 4.

Abstract: A membrane for fluid separation made of a blend of at least a polyimide polymer and a polyimidazole polymer.

Abstract: The invention relates to a method for producing membrane, in particular gas separation membrane, wherein the membrane comprises a selective separating layer. The following steps are carried out: a) a polymer solution is produced from at least one polymer and at least one polyglycol ether, b) the polymer solution is cast into a film, c) in a further step, the selective separating layer is produced from the film, preferably by drying. The invention, among other things, further relates to a membrane, in particular gas separation membrane, comprising a selective separating layer.

Abstract: The invention discloses a composition comprising a hybrid composite organic-inorganic membrane. The hybrid organic-inorganic membrane according to the present invention may comprise an amorphous porous layer incorporating organic functionalities. The amorphous porous layer may be deposited on a porous alumina substrate by chemical vapor deposition (CVD). The amorphous porous layer may comprise a single top-layer (STL), multiple top-layers (MTL) or mixed top-layers (XTL). The substrate may comprise a single layer or multiple graded layers of alumina.

Abstract: A nanoscale membrane exposed on opposite sides thereof and having an average thickness of less than about 100 nm, and a lateral length to thickness aspect ratio that is more than 10,000 to 1 is disclosed. Also disclosed are methods of making such membranes, and use thereof in a number of devices including fuel cells, sensor devices, electrospray devices, and supports for examining a sample under electron microscopy.

Abstract: The present invention discloses a blends of an aromatic polyimide polymer and a polymer containing aromatic sulfonic acid groups that can be converted into polybenzoxazole (PBO) membranes for gas, vapor, and liquid separations. The PBO membranes that were prepared by thermal treating aromatic polyimide membranes containing between 0.05 and 20 wt-% of a poly(styrene sulfonic acid) polymer. These polymers showed up to 95% improvement in selectivity for CO2/CH4 and H2/CH4 separations compared to PBO membranes prepared from corresponding aromatic polyimide membranes without a poly(styrene sulfonic acid) polymer.

Abstract: A membrane suitable for separating a gas, in particular carbon dioxide, from a gas mixture containing the gas is provided by a blend of polyvinyl alcohol (PVA) and polyvinylamine (PVAm).

Abstract: A membrane for use in an implantable glucose sensor including at least one crosslinked substantially hydrophobic polymer and at least one crosslinked substantially hydrophilic polymer; wherein the first and second polymers are different polymers and substantially form an interpenetrating polymer network, semi-interpenetrating polymer network, polymer blend, or copolymer. The membranes are generally characterized by providing a permeability ratio of oxygen to glucose of about 1 to about 1000 in units of (mg/dl glucose) per (mmHg oxygen). Three methods of making membranes from hydrophobic and hydrophilic monomers formed into polymer networks are provided, wherein according to at least two of the methods, the monomers may be substantially immiscible with one another.

Abstract: Disclosed are a gas separation membrane and a gas separation method in which at least one species of organic vapor is separated and recovered from an organic vapor mixture using the gas separation membrane. The gas separation membrane is made of an aromatic polyimide composed of a tetracarboxylic acid component consisting of an aromatic ring-containing tetracarboxylic acid and a diamine component comprising 10 to 90 mol % of a combination of (B1) 3,4?-diaminodiphenyl ether and (B2) 4,4?-diaminodiphenyl ether at a B1 to B2 molar ratio, B1/B2, ranging from 10/1 to 1/10, and 10 to 90 mol % of other aromatic diamine.

Abstract: This invention discloses a composition of, a method of making, and an application of high plasticization-resistant chemically cross-linked organic-inorganic hybrid membranes such as cross-linked cellulose acetate-cellulose triacetate-polyurethanepropylsilsesquioxane membranes. These cross-linked membranes with covalently interpolymer-chain-connected hybrid networks were prepared via a sol-gel condensation polymerization of cross-linkable organic polymer-organosilicon alkoxide precursor membrane materials. CO2 plasticization tests on these cross-linked membranes demonstrate extremely high CO2 plasticization resistance under CO2 pressure up to 5516 kPa (800 psig). These new cross-linked membranes can be used not only for gas separations such as CO2/CH4 and CO2/N2 separations, O2/N2 separation, olefin/paraffin separations (e.g. propylene/propane separation), iso/normal paraffins separations, but also for liquid separations such as desalination.

Abstract: The present invention relates to gas separation membranes for separating carbon dioxide from other gas species, polymer compositions suitable for this application, and processes for the manufacture thereof. In particular, the present invention relates polymeric compositions comprising a host polymer that is permeable to the targeted gas species, such as carbon dioxide and has a selectivity for the target gas species over other gas species. The polymeric composition also comprises domains of a polymeric material that are, for example at least 0.5 nm in diameter and that have a higher permeability for the targeted gas compared to the host polymer. The present invention can provide membranes that have a permeability and selectivity above the Robeson's upper bound.

Abstract: Provided is a method of manufacturing a porous polytetrafluoroethylene (PTFE) membrane capable of achieving both a high collection efficiency and a low pressure drop, though it has a larger average pore size and a greater thickness than conventional porous PTFE membranes. This manufacturing method includes: stretching an unsintered polytetrafluoroethylene sheet by a factor of 5 to 30 in a predetermined direction at a temperature equal to or higher than the melting point of polytetrafluoroethylene; further stretching the stretched sheet by a factor of 5 to 40 in a direction different from the predetermined direction at a temperature lower than the melting point; and after the stretchings, heating the stretched sheet at a temperature equal to or higher than the melting point.

Abstract: The invention under consideration concerns novel his-molecular-weight polyazoles, which are suitable for the production of fibers, films, membranes, and molded articles, on the basis of their high molecular weight, expressed as intrinsic viscosity, of at least 1.3 dl/g. Moreover, the invention under consideration describes a method for the production of high-molecular-weight polyazoles.

Abstract: A process of producing an asymmetric membrane of multicomponent polyimide. The process includes the steps of (1) preparing a multicomponent polyimide blend solution by mixing a polyimide component A having a number-averaged polymerization index NA and a polyimide component B having a number-averaged polymerization index NB, wherein NA and NB satisfies equation 1: 2.35×NA?2.09<NB<450×NA?1.12??1 (2) subjecting the multicomponent polyimide blend solution to further polymerization and imidation reaction, and (3) causing a phase inversion in the resulting multicomponent polyimide blend solution to form an asymmetric membrane. The polyimide component A is raw materials of polyimide A containing a fluorine atom in the chemical structure thereof and/or a polymerization and imidation reaction product of the raw materials. The polyimide component B is raw materials of polyimide B and/or a polymerization and imidation reaction product of the raw materials.

Abstract: A gas separation membrane comprises a blend of polyethersulfone (PES) and aromatic polyimide polymers that may comprise a plurality of first repeating units of formula (I), wherein X1, X 2 and X3 are herein defined.

Abstract: The present invention discloses a novel method of making high performance mixed matrix membranes (MMMs) using stabilized concentrated suspensions of solvents, uniformly dispersed polymer stabilized molecular sieves, and at least two different types of polymers as the continuous blend polymer matrix. MMMs as dense films or asymmetric flat sheet or hollow fiber membranes fabricated by the method described in the current invention exhibit significantly enhanced permeation performance for separations over the polymer membranes made from the continuous blend polymer matrix. MMMs of the present invention are suitable for a wide range of gas, vapor, and liquid separations such as alcohol/water, CO2/CH4, H2/CH4, O2/N2, CO2/N2, olefin/paraffin, iso/normal paraffins, and other light gases separations.