# US 10,369,525 B2 · Filtration membranes with nanoscale patterns > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,369,525 B2 - Document ID: US10369525B2 - Status: Granted - Kind: B2 - Application number: 14/426,670 - Filed: 2013-09-06 - Published: 2015-08-27 - Granted: 2019-08-06 - Earliest claimed: 2012-09-06 - Assignees: The Regents of the University of Colorado, a body corporate - Applicants: The Regents of the University of Colorado, a body corporate - Inventors: Yifu Ding; Sajjad Maruf; John Pellegrino; Alan Greenberg - Web page: https://patentgrep.com/patent/US10369525B2 ## CPC - B01D 67/0032: {by elimination of segments of the precursor, e.g. nucleation-track membranes, lithography or laser methods} - B01D 61/025: {Reverse osmosis; Hyperfiltration} - B01D 61/145: {Ultrafiltration} - B01D 61/147: {Microfiltration} - B01D 67/0002: {Organic membrane manufacture} - B01D 69/02: characterised by their properties - B01D 71/68: Polysulfones; Polyethersulfones - B01D 71/701: {Polydimethylsiloxane} - B29C 59/02: by mechanical means, e.g. pressing {(B29C59/007 takes precedence; embossing expanded porous articles B29C44/5627)} - B01D 65/08: Prevention of membrane fouling or of concentration polarisation - B01D 2325/08: Patterned membranes - B29L 2007/00: Flat articles, e.g. films or sheets (B29L2024/00 takes precedence) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract A membrane for fluid transfer includes a base membrane and a pattern, that covers a working area of a surface thereof, formed of a compatible material. The pattern has periodicity and/or amplitude that do not exceed 1 micrometer. A method of filtering a component from a solution includes passing the solution comprising the component through a membrane that includes a base membrane. The base membrane and a pattern that covers a working area of a surface thereof are formed of materials compatible with the solution. The pattern has periodicity and/or amplitude that do not exceed 1 micrometer, and reduces mass transfer of surface-accumulative soluble and/or suspended species and particulates from the solution to the membrane while the solution is passed through the membrane. A method of producing a membrane for fluid transfer includes forming a nanoscale pattern over a working area of a polymer membrane. ## Claims ### Claim 1 A patterned membrane for fluid transfer, comprising: a base membrane having a first surface and a second surface counterfacing the first surface, the base membrane being permeable, a pattern that covers a working area of the first surface, the pattern having been formed by imprinting the base membrane with features with a periodicity and an amplitude that do not exceed 1 micrometer in size, wherein the base membrane remains permeable and the features of the pattern are permeable to a solvent fluid that is transported through the patterned membrane, and wherein the patterned membrane obstructs, at the first surface, a mass transfer through the patterned membrane of at least surface-accumulative solutes and insoluble particles. ### Claim 2 (depends on 1) The patterned membrane of claim 1, the pattern being formed by nanolithography on the first surface, wherein the periodicity and amplitude of the pattern is further configured to obstruct, at the first surface, a portion, but not all, of the mass transfer through the patterned membrane of the surface-accumulative solutes and insoluble particles. ### Claim 3 (depends on 1) The patterned membrane of claim 1, wherein the base membrane and the pattern are comprised of a material that is capable of filtering a polar solvent selected from the group consisting dichloromethane, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethyl sulfoxide, propylene carbonate, formic acid, n-butanol, isopropanol, n-propanol, ethanol, methanol, acetic acid and water. ### Claim 4 (depends on 1) The patterned membrane of claim 1, wherein the base membrane and the pattern are comprised of a material that is capable of filtering a non-polar solvent selected from the group consisting of pentane, cyclopentane, hexane, cyclohexane, benzene, toluene, 1,4-dioxane, chloroform, and diethyl ether. ### Claim 5 (depends on 1) The patterned membrane of claim 1, wherein the base membrane is a reverse osmosis membrane, and at least one of the base membrane or the pattern comprises a material selected from the group consisting of cellulose acetates, polypiperazine amides, and polyamides. ### Claim 6 (depends on 1) The patterned membrane of claim 1, wherein the base membrane and the pattern are composed of a material that is capable of filtering a gas, and at least one of the base membrane or the pattern comprise polydimethylsiloxane. ### Claim 7 (depends on 1) The patterned membrane of claim 1, wherein the the membrane is a microfiltration membrane, and pattern comprises raised or depressed portions that form shapes that include one or more of ridges, valleys, channels, hills, posts, peaks, needles, pins, knobs, parallel lines, intersecting lines or concentric lines on the patterned membrane. ### Claim 8 (depends on 1) The patterned membrane of claim 1, wherein the pattern comprises projections arranged on the base membrane, the periodicity of the projections being between 10 and 2000 nm. ### Claim 9 (depends on 8) The patterned membrane of claim 8, wherein the projections have a maximum width of between 300 and 500 nm. ### Claim 10 (depends on 1) The patterned membrane of claim 1, wherein pattern comprises one or more of parallel lines, intersecting lines, or concentric lines that form a projection surrounded on one or both sides by a valley, and wherein the pattern further comprises a peak-to-valley height of between 100 and 300 nm. ### Claim 11 (depends on 1) The patterned membrane of claim 1, wherein: the base membrane is an ultrafiltration membrane, and at least one of the base membrane or the pattern comprise a material selected from the group consisting of poly (ether suflone), polyacrylonitrile, polyvinylidene, regenerated cellulose, cellulose acetate, polysulfone, polypropylene, polyarylether sulfones, polyvinylidene fluoride, polyvinyl chloride, polyketones, polyether ketones, polytetrafluoroethylene, polyimides, and polyamides. ### Claim 12 (depends on 1) The patterned membrane of claim 1, wherein: the base membrane is a nanofiltration membrane, and at least one of the base membrane or the pattern comprise a material selected from the group consisting of cellulose acetate, polypiperazine amide, polyamides, polyethylene, polypropylene, polysulphones, polyethersulphones, polytetrafluoroethylene, polyvinylidenedifluoride, polyimides, and polyacrylonitriles. ### Claim 13 (depends on 1) The patterned membrane of claim 1, wherein: the base membrane is a microfiltration membrane, and at least one of the base membrane and the pattern comprise a material selected from the group consisting of nylon, mixed cellulose esters, regenerated cellulose, cellulose acetate, polycarbonate, polytetrafluoroethylenes, polypropylene, polystyrene, polyvinylchloride, polysulfone, poly(ether sulfone), and polyethylene. ### Claim 14 A patterned membrane for fluid transfer, comprising: a base membrane having a first surface and a second surface counterfacing the first surface, the base membrane being permeable, a pattern that covers a working area of the first surface, the pattern having been formed by a permeable material that is compatible with the base membrane, the pattern forming features with a periodicity and an amplitude that does not exceed 1micrometer in size, wherein the patterned membrane remains permeable to a solvent fluid that is transported through the patterned membrane, and wherein the patterned membrane obstructs, at the first surface, a mass transfer through the patterned membrane of at least surface-accumulative solutes and insoluble particles. ### Claim 15 (depends on 14) The patterned membrane of claim 14, the pattern being formed by nanolithography on the first surface, wherein the periodicity and amplitude of the pattern is further configured to obstruct, at the first surface, a portion, but not all, of the mass transfer through the patterned membrane of the surface-accumulative solutes and insoluble particles. ### Claim 16 (depends on 14) The patterned membrane of claim 14, wherein the base membrane and the pattern are comprised of a material that is capable of filtering a polar solvent selected from the group consisting of dichloromethane, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethyl sulfoxide, propylene carbonate, formic acid, n-butanol, isopropanol, n-propanol, ethanol, methanol, acetic acid, and water. ### Claim 17 (depends on 14) The patterned membrane of claim 14, wherein the base membrane and the pattern are comprised of a material that is capable of filtering a non-polar solvent selected from the group consisting of pentane, cyclopentane, hexane, cyclohexane, benzene, toluene, 1,4-dioxane, chloroform and diethyl ether. ### Claim 18 (depends on 14) The patterned membrane of claim 14, wherein the base membrane is a reverse osmosis membrane, and at least one of the base membrane or the pattern comprises a material selected from the group consisting of cellulose acetates, polypiperazine amides, and polyamides. ### Claim 19 (depends on 14) The patterned membrane of claim 14, wherein the base membrane and the pattern are composed of a material that is capable of filtering a gas, and at least one of the base membrane or the pattern comprise polydimethylsiloxane. ### Claim 20 (depends on 14) The patterned membrane of claim 14, wherein the pattern comprises raised or depressed portions that form shapes that include one or more of ridges, valleys, channels, hills, posts, peaks, needles, pins, knobs, parallel lines, intersecting lines or concentric lines on the patterned membrane. ### Claim 21 (depends on 14) The patterned membrane of claim 14, wherein the pattern comprises projections arranged on the base membrane, the periodicity of the projections being between 10 and 2000 nm. ### Claim 22 (depends on 21) The patterned membrane of claim 21, wherein the projections have a maximum width of between 300 and 500 nm. ### Claim 23 (depends on 14) The patterned membrane of claim 14, wherein the pattern comprises one or more of parallel lines, intersecting lines, or concentric lines that form a projection surrounded on one or both sides by a valley and wherein the pattern further comprises a peak-to-valley height of between 100 and 300 nm. ### Claim 24 (depends on 14) The patterned membrane of claim 14, wherein: the base membrane is an ultrafiltration membrane, and at least one of the base membrane or the pattern comprise a material selected from the group consisting of poly (ether suflone), polyacrylonitrile, polyvinylidene, regenerated cellulose, cellulose acetate, polysulfone, polypropylene, polyarylether sulfones, polyvinylidene fluoride, polyvinyl chloride, polyketones, polyether ketones, polytetrafluoroethylene, polyimides, and polyamides. ### Claim 25 (depends on 14) The patterned membrane of claim 14, wherein: the base membrane is a nanofiltration membrane, and at least one of the base membrane or the pattern comprise a material selected from the group consisting of cellulose acetate, polypiperazine amide, polyamides, polyethylene, polypropylene, polysulphones, polyethersulphones, polytetrafluoroethylene, polyvinylidenedifluoride, polyimides, and polyacrylonitriles. ### Claim 26 (depends on 14) The patterned membrane of claim 14, wherein: the base membrane is a microfiltration membrane, and at least one of the base membrane and the pattern comprise a material selected from the group consisting of nylon, mixed cellulose esters, regenerated cellulose, cellulose acetate, polycarbonate, polytetrafluoroethylenes, polypropylene, polystyrene, polyvinylchloride, polysulfone, poly(ether sulfone), and polyethylene. ### Claim 27 A method filtering a component from a solution, comprising: passing the solution comprising the component through a patterned membrane that includes: a base membrane having a first surface and a second surface counterfacing the first surface, the base membrane being permeable, a pattern that covers a working area of the first surface, the pattern having been formed by imprinting the base membrane with features with a periodicity and an amplitude that does not exceed 1 micrometer in size, wherein the base membrane remains permeable and the features of the pattern are permeable to a solvent fluid that is transported through the patterned membrane, and wherein the patterned membrane obstructs, at the first surface, a mass transfer through the patterned membrane of at least surface-accumulative solutes and insoluble particles. ### Claim 28 (depends on 27) The method of claim 27, wherein the component has a molecular weight of between 0.1 and 1000 kDa. ### Claim 29 (depends on 27) The method claim 27, wherein the passing the solution comprises adjusting one of flow and pressure of the solution to provide a sub-critical flux of the solution through the membrane. ### Claim 30 A method filtering a component from a solution, comprising: passing the solution comprising the component through a patterned membrane that includes: a base membrane having a first surface and a second surface counterfacing the first surface, the base membrane being permeable, a pattern that covers a working area of the first surface, the pattern having been formed by a permeable material that is compatible with the base membrane, the pattern forming features with a periodicity and an amplitude that does not exceed 1 micrometer in size, wherein the patterned membrane remains permeable to a solvent fluid that is transported through the patterned membrane, and wherein the patterned membrane obstructs, at the first surface, a mass transfer through the patterned membrane of at least surface-accumulative solutes and insoluble particles. ### Claim 31 (depends on 30) The method of claim 30, wherein the component has a molecular weight of between 0.1 and 1000 kDa. ### Claim 32 (depends on 30) The method claim 30, wherein the passing the solution comprises adjusting one of flow and pressure of the solution to provide a sub-critical flux of the solution through the membrane.