# US 11,896,935 B2 · Filtration membranes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,896,935 B2 - Document ID: US11896935B2 - Status: Granted - Kind: B2 - Application number: 15/680,064 - Filed: 2017-08-17 - Published: 2019-02-21 - Granted: 2024-02-13 - Earliest claimed: 2017-08-17 - Assignees: Uchicago Argonne, LLC; The University of Chicago - Applicants: Uchicago Argonne, LLC; The University of Chicago - Inventors: Seth B. Darling; Jeffrey W. Elam; Ruben Waldman - Web page: https://patentgrep.com/patent/US11896935B2 ## CPC - B01D 69/02: characterised by their properties - B01D 67/0002: {Organic membrane manufacture} - B01D 67/0079: {Manufacture of membranes comprising organic and inorganic components} - B01D 69/1251: {by interfacial polymerisation} - B01D 69/141: {Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes} - B01D 71/36: Polytetrafluoroethylene - B01D 71/421: {Polyacrylonitrile} - B01D 67/0072: {by deposition from the gaseous phase, e.g. sputtering, CVD, PVD} - B01D 69/105: {Support pretreatment} - B01D 69/148: {Organic/inorganic mixed matrix membranes} - B01D 71/34: Polyvinylidene fluoride - B01D 71/68: Polysulfones; Polyethersulfones - B01D 71/82: characterised by the presence of specified groups, e.g. introduced by chemical after-treatment - 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) ## Abstract Polymeric membranes are modified via SIS to promote membrane resilience, prolong membrane lifetime, and mitigate fouling. Modified membranes include an inorganic material within an outer portion of the modified membrane and a polymeric core that remains unmodified by the inorganic material. The polymer may be removed leaving an inorganic material patterned from an initial unmodified polymeric membrane. ## Claims ### Claim 1 A method for forming a membrane with inorganic features comprising: (a) exposing a polymer membrane, which comprises a polyvinylidene fluoride polymer substrate, with a first precursor, comprising trimethyl aluminum (TMA), wherein exposing the first precursor comprises exposing the TMA in at least five exposure pulses for at least 5 continuous minutes of dwell time with a first precursor partial pressure of 1 torr to form by a first reaction a first layer within a bulk of the polymer substrate; (b) purging excess first precursor and first reaction by-product; (c) reacting the first layer with a second precursor within the bulk of the polymer substrate by a second reaction; and (d) purging excess second precursor and second reaction by-product, wherein steps (a) to (d) constitute one cycle and steps (a) to (d) are repeated 0 to 4 times, and forming the membrane with inorganic features comprising an inorganic shell within the polymer substrate. ### Claim 2 (depends on 1) The method of claim 1, wherein each of the at least five exposure pulses is 0.04 seconds and wherein 20 seconds separates each exposure pulse. ### Claim 3 (depends on 1) The method of claim 1, wherein the second precursor is an oxidizer. ### Claim 4 (depends on 1) The method of claim 1, wherein the second precursor comprises water. ### Claim 5 (depends on 1) The method of claim 1, further comprising treating the polymer substrate with a hydrophilic enhancer prior to exposing the first precursor to the polymer substrate. ### Claim 6 (depends on 1) The method of claim 1, further comprising removing the polymer substrate from the membrane so that the membrane comprises the inorganic shell. ### Claim 7 (depends on 6) The method of claim 6, wherein removing the polymer substrate comprises a process selected from thermal treatment, plasma treatment, or chemical treatment. ### Claim 8 (depends on 1) The method of claim 1, comprising repeating steps (a) to (d) 0 to 4 times, wherein the inorganic shell is the outer 10% of the membrane. ### Claim 9 (depends on 1) The method of claim 1, further comprising, during one or both of reacting the polymer substrate with the first precursor and reacting the first layer with the second precursor, providing a backflow of inert backflow gas. ### Claim 10 A method for forming a membrane with inorganic features comprising: (a) exposing a polymer membrane, which comprises a polymer substrate, with a first precursor, comprising trimethyl aluminum (TMA), wherein exposing the first precursor comprises exposing the TMA in at least five exposure pulses for at least 5 continuous minutes of dwell time with a first precursor partial pressure of 1 torr to form by a first reaction a first layer within a bulk of the polymer substrate; (b) purging excess first precursor and first reaction by-product; (c) reacting, by a second reaction, the first layer with a second precursor within the bulk of the polymer substrate; and (d) purging excess second precursor and second reaction by-product, wherein steps (a) to (d) constitute one cycle and steps (a) to (d) are repeated 0 to 4 times, forming the membrane with inorganic features comprising an inorganic shell within the polymer substrate.