# US 12,214,318 B2 · Molecularly-mixed composite membranes and methods for making the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,318 B2 - Document ID: US12214318B2 - Status: Granted - Kind: B2 - Application number: 16/971,353 - Filed: 2019-02-20 - Published: 2020-12-17 - Granted: 2025-02-04 - Earliest claimed: 2018-02-20 - Assignees: Georgia Tech Research Corporation - Applicants: Georgia Tech Research Corporation - Inventors: Guanghui Zhu; Ryan P. Lively - Web page: https://patentgrep.com/patent/US12214318B2 ## CPC - B01D 69/12: Composite membranes; Ultra-thin membranes - B01D 67/0011: {Casting solutions therefor} - B01D 67/0013: {Casting processes} - B01D 69/02: characterised by their properties - B01D 69/1411: {containing dispersed material in a continuous matrix} - B01D 53/228: {characterised by specific membranes} - B01D 2257/102: Nitrogen - B01D 2257/504: Carbon dioxide - B01D 2257/7025: Methane - B01D 2323/50: Control of the membrane preparation process - B01D 2325/20: Specific permeability or cut-off range - Y02C 20/20: of methane - 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) - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] ## Abstract Disclosed herein is a molecularly-mixed composite membrane comprising an amorphous scrambled porous organic compound (ASPOC) material and a polymer. With current developments in membrane technologies, there exists a need for largely scalable membranes and improved performance with difficult molecular separations. Mixed Matrix Membranes improve separation performance to a degree, but also increase the membrane defects as the filler material aggregates into particles that disrupt the membrane matrix. The disclosed membrane is configured to reduce defects and increase homogeneity. The disclosed ASPOC material avoids aggregation and disperses uniformly in the polymer matrix, creating a molecularly-mixed composite membrane with improved separation performance. Also disclosed herein are methods for making the same. ## Claims ### Claim 1 A molecularly-mixed composite membrane (MMCM) comprising: a solution comprising: a porous molecular material comprising porous organic cages (POCs); and a polymer; wherein the porous molecular material is dissolved in the polymer; and wherein the porous molecular material is so uniformly distributed in the polymer as to form the solution as if it were a single-phase solution; and wherein the MMCM is substantially defect-free, presenting: a high level of homogeneity indicative of single POCs surrounded by the polymer; and an attendant low degree of crystallinity or particle aggregation indicative of negligible POC-POC bonding. ### Claim 2 (depends on 1) The membrane of claim 1, wherein the porous molecular material comprises an amorphous scrambled porous organic cage ASPOC material with the stronger polymer-cage interactions than cage-cage interactions. ### Claim 3 (depends on 1) The membrane of claim 1, wherein a glass transition onset temperature of the membrane is greater than a glass transition onset temperature of the polymer. ### Claim 4 (depends on 1) The membrane of claim 1, wherein a glass transition midpoint temperature of the membrane is greater than a glass transition midpoint temperature of the polymer. ### Claim 5 (depends on 1) The membrane of claim 1, wherein a swelling volume of the membrane is less than a swelling volume of the polymer. ### Claim 6 (depends on 1) The membrane of claim 1, wherein one or more of: a glass transition onset temperature of the membrane is greater than a glass transition onset temperature of the polymer; a glass transition midpoint temperature of the membrane is greater than a glass transition midpoint temperature of the polymer; or a swelling volume of the membrane is less than a swelling volume of the polymer. ### Claim 7 (depends on 6) The membrane of claim 6, wherein at least one of: the membrane presents a carbon dioxide permeability of 20 barrer or greater; or the membrane presents a diffusion coefficient greater than a diffusion coefficient of the polymer. ### Claim 8 (depends on 1) The membrane of claim 1, wherein the membrane presents a methane permeability of 0.75 barrer or greater. ### Claim 9 (depends on 1) The membrane of claim 1, wherein the membrane presents a nitrogen permeability of 1 barrer or greater. ### Claim 10 (depends on 1) The membrane of claim 1, wherein the membrane presents a SF6 permeability of 0.01 barrer or greater. ### Claim 11 (depends on 1) A method of making the membrane of claim 1 comprising: mixing a dope solution comprising: the polymer; the porous molecular material; and a first solvent configured to dissolve the polymer and the porous molecular material to form the dope solution; and casting the mixed dope solution; wherein at least one of: a glass transition onset temperature of the casted mixed dope solution is greater than a glass transition onset temperature of the polymer; a glass transition midpoint temperature of the casted mixed dope solution is greater than a glass transition midpoint temperature of the polymer; or a swelling volume of the casted mixed dope solution is less than a swelling volume of the polymer. ### Claim 12 (depends on 11) The method of claim 11, wherein mixing comprises sonication. ### Claim 13 (depends on 12) The method of claim 12, wherein the sonication occurs for 1 minute or less. ### Claim 14 (depends on 11) The method of claim 11, wherein casting comprises spin-coating the solution on pre-formed crosslinked polyimide supports. ### Claim 15 (depends on 11) The method of claim 11, wherein casting comprises casting the membrane as a standalone membrane. ### Claim 16 (depends on 11) The method of claim 11 further comprising annealing the casted mixed dope solution under vacuum. ### Claim 17 (depends on 11) The method of claim 11, wherein the mixed dope solution is homogeneous. ### Claim 18 (depends on 11) The method of claim 11 further comprising synthesizing the porous molecular material. ### Claim 19 (depends on 18) The method of claim 18, wherein synthesizing comprises: mixing a second solution comprising: an aldehyde material; at least one diamine material; and a second solvent; and evaporating at least a portion of the second solvent. ### Claim 20 (depends on 19) The method of claim 19 further comprising drying the porous molecular material. ### Claim 21 (depends on 19) The method of claim 19 further comprising washing the porous molecular material with a nonsolvent. ### Claim 22 (depends on 11) The method of claim 11 further comprising evaporating at least a portion of the first solvent. ### Claim 23 (depends on 11) The method of claim 11, wherein one or more of: the mixed dope solution presents a diffusion coefficient greater than a diffusion coefficient of the polymer; the mixed dope solution presents a methane permeability of 0.75 barrer or greater; the mixed dope solution presents a nitrogen permeability of 1 barrer or greater; or the mixed dope solution presents a SF6 permeability of 0.01 barrer or greater.