WO2015070004A1 - Zwitterion-containing membranes - Google Patents
Zwitterion-containing membranes Download PDFInfo
- Publication number
- WO2015070004A1 WO2015070004A1 PCT/US2014/064528 US2014064528W WO2015070004A1 WO 2015070004 A1 WO2015070004 A1 WO 2015070004A1 US 2014064528 W US2014064528 W US 2014064528W WO 2015070004 A1 WO2015070004 A1 WO 2015070004A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- statistical copolymer
- repeat units
- weight
- filtration membrane
- methacrylate
- Prior art date
Links
- 239000012528 membrane Substances 0.000 title claims abstract description 142
- 229920006301 statistical copolymer Polymers 0.000 claims abstract description 83
- 238000001914 filtration Methods 0.000 claims abstract description 52
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 35
- 238000000034 method Methods 0.000 claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 44
- 239000011148 porous material Substances 0.000 claims description 28
- 229940117986 sulfobetaine Drugs 0.000 claims description 25
- PSBDWGZCVUAZQS-UHFFFAOYSA-N (dimethylsulfonio)acetate Chemical compound C[S+](C)CC([O-])=O PSBDWGZCVUAZQS-UHFFFAOYSA-N 0.000 claims description 19
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 claims description 17
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 claims description 15
- -1 pyridinium alkyl sulfonate Chemical class 0.000 claims description 15
- QTKPMCIBUROOGY-UHFFFAOYSA-N 2,2,2-trifluoroethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCC(F)(F)F QTKPMCIBUROOGY-UHFFFAOYSA-N 0.000 claims description 14
- 230000004907 flux Effects 0.000 claims description 12
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 claims description 11
- 239000004695 Polyether sulfone Substances 0.000 claims description 9
- 229920006393 polyether sulfone Polymers 0.000 claims description 9
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 8
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 8
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 8
- 230000009477 glass transition Effects 0.000 claims description 6
- 229920012287 polyphenylene sulfone Polymers 0.000 claims description 6
- DNHDSWZXBHTLDP-UHFFFAOYSA-N 3-(2-ethenylpyridin-1-ium-1-yl)propane-1-sulfonate Chemical compound [O-]S(=O)(=O)CCC[N+]1=CC=CC=C1C=C DNHDSWZXBHTLDP-UHFFFAOYSA-N 0.000 claims description 5
- LQTOWWAWSGQJND-UHFFFAOYSA-N 3-(4-ethenylpyridin-1-ium-1-yl)propane-1-sulfonate Chemical compound [O-]S(=O)(=O)CCC[N+]1=CC=C(C=C)C=C1 LQTOWWAWSGQJND-UHFFFAOYSA-N 0.000 claims description 5
- 108091003079 Bovine Serum Albumin Proteins 0.000 claims description 4
- 229940098773 bovine serum albumin Drugs 0.000 claims description 4
- 229920001519 homopolymer Polymers 0.000 claims description 4
- 239000007764 o/w emulsion Substances 0.000 claims description 4
- 150000003440 styrenes Chemical class 0.000 claims description 4
- QGPNBXOLVRTTAX-UHFFFAOYSA-N C(C=C)(=O)N.P(=O)#C[N+](CCO)(C)C Chemical compound C(C=C)(=O)N.P(=O)#C[N+](CCO)(C)C QGPNBXOLVRTTAX-UHFFFAOYSA-N 0.000 claims description 3
- 239000004696 Poly ether ether ketone Substances 0.000 claims description 3
- 239000004952 Polyamide Substances 0.000 claims description 3
- 239000004642 Polyimide Substances 0.000 claims description 3
- 239000004721 Polyphenylene oxide Substances 0.000 claims description 3
- 239000004743 Polypropylene Substances 0.000 claims description 3
- 229920002678 cellulose Polymers 0.000 claims description 3
- 238000007334 copolymerization reaction Methods 0.000 claims description 3
- NPNRJNCGQAMFGP-UHFFFAOYSA-N dimethyl-[(oxo-$l^{5}-phosphanylidyne)methyl]-(2-prop-2-enoyloxyethyl)azanium Chemical compound O=P#C[N+](C)(C)CCOC(=O)C=C NPNRJNCGQAMFGP-UHFFFAOYSA-N 0.000 claims description 3
- UGRPVKNKPUXYKL-UHFFFAOYSA-N dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]-[(oxo-$l^{5}-phosphanylidyne)methyl]azanium Chemical compound CC(=C)C(=O)OCC[N+](C)(C)C#P=O UGRPVKNKPUXYKL-UHFFFAOYSA-N 0.000 claims description 3
- 229950004354 phosphorylcholine Drugs 0.000 claims description 3
- 229920002492 poly(sulfone) Polymers 0.000 claims description 3
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 3
- 229920002647 polyamide Polymers 0.000 claims description 3
- 229920002530 polyetherether ketone Polymers 0.000 claims description 3
- 229920001721 polyimide Polymers 0.000 claims description 3
- 229920006380 polyphenylene oxide Polymers 0.000 claims description 3
- 229920001155 polypropylene Polymers 0.000 claims description 3
- 239000004800 polyvinyl chloride Substances 0.000 claims description 3
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 3
- 238000001338 self-assembly Methods 0.000 claims description 3
- 230000002427 irreversible effect Effects 0.000 claims description 2
- 230000037361 pathway Effects 0.000 claims description 2
- 150000003254 radicals Chemical class 0.000 claims description 2
- YHHSONZFOIEMCP-UHFFFAOYSA-O phosphocholine Chemical compound C[N+](C)(C)CCOP(O)(O)=O YHHSONZFOIEMCP-UHFFFAOYSA-O 0.000 claims 2
- 229920001577 copolymer Polymers 0.000 description 41
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 36
- 239000010410 layer Substances 0.000 description 25
- 239000000243 solution Substances 0.000 description 20
- 239000000975 dye Substances 0.000 description 18
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 14
- 239000000523 sample Substances 0.000 description 14
- 230000015572 biosynthetic process Effects 0.000 description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 10
- 238000000576 coating method Methods 0.000 description 10
- 239000011541 reaction mixture Substances 0.000 description 10
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 9
- 239000011248 coating agent Substances 0.000 description 9
- 230000035699 permeability Effects 0.000 description 9
- 239000002904 solvent Substances 0.000 description 9
- 238000003756 stirring Methods 0.000 description 9
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 7
- RHQDFWAXVIIEBN-UHFFFAOYSA-N Trifluoroethanol Chemical compound OCC(F)(F)F RHQDFWAXVIIEBN-UHFFFAOYSA-N 0.000 description 7
- NWVVVBRKAWDGAB-UHFFFAOYSA-N p-methoxyphenol Chemical compound COC1=CC=C(O)C=C1 NWVVVBRKAWDGAB-UHFFFAOYSA-N 0.000 description 7
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 6
- 239000002131 composite material Substances 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 239000010409 thin film Substances 0.000 description 6
- OZAIFHULBGXAKX-VAWYXSNFSA-N AIBN Substances N#CC(C)(C)\N=N\C(C)(C)C#N OZAIFHULBGXAKX-VAWYXSNFSA-N 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 238000003786 synthesis reaction Methods 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 238000005160 1H NMR spectroscopy Methods 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 125000000129 anionic group Chemical group 0.000 description 3
- 230000003373 anti-fouling effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000010408 film Substances 0.000 description 3
- 125000000524 functional group Chemical group 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 239000003112 inhibitor Substances 0.000 description 3
- 238000010926 purge Methods 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 238000003887 surface segregation Methods 0.000 description 3
- 238000000108 ultra-filtration Methods 0.000 description 3
- IAZDPXIOMUYVGZ-WFGJKAKNSA-N Dimethyl sulfoxide Chemical compound [2H]C([2H])([2H])S(=O)C([2H])([2H])[2H] IAZDPXIOMUYVGZ-WFGJKAKNSA-N 0.000 description 2
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 2
- 238000005481 NMR spectroscopy Methods 0.000 description 2
- 238000003917 TEM image Methods 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000010612 desalination reaction Methods 0.000 description 2
- 239000003814 drug Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011067 equilibration Methods 0.000 description 2
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000012466 permeate Substances 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 2
- 238000004627 transmission electron microscopy Methods 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- BYEAHWXPCBROCE-UHFFFAOYSA-N 1,1,1,3,3,3-hexafluoropropan-2-ol Chemical compound FC(F)(F)C(O)C(F)(F)F BYEAHWXPCBROCE-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 238000003556 assay Methods 0.000 description 1
- 235000013361 beverage Nutrition 0.000 description 1
- 229960000074 biopharmaceutical Drugs 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 235000013365 dairy product Nutrition 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007606 doctor blade method Methods 0.000 description 1
- 239000012527 feed solution Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 235000019341 magnesium sulphate Nutrition 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000009285 membrane fouling Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000302 molecular modelling Methods 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- PYJNAPOPMIJKJZ-UHFFFAOYSA-N phosphorylcholine chloride Chemical compound [Cl-].C[N+](C)(C)CCOP(O)(O)=O PYJNAPOPMIJKJZ-UHFFFAOYSA-N 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 238000010526 radical polymerization reaction Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 238000002798 spectrophotometry method Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 239000010918 textile wastewater Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
- C08F220/12—Esters of monohydric alcohols or phenols
- C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
- C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
- C08F220/1802—C2-(meth)acrylate, e.g. ethyl (meth)acrylate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/12—Composite membranes; Ultra-thin membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/28—Polymers of vinyl aromatic compounds
- B01D71/281—Polystyrene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/40—Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
- B01D71/42—Polymers of nitriles, e.g. polyacrylonitrile
- B01D71/421—Polyacrylonitrile
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/66—Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
- B01D71/68—Polysulfones; Polyethersulfones
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/76—Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/76—Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74
- B01D71/80—Block polymers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
- C08F220/22—Esters containing halogen
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/42—Nitriles
- C08F220/44—Acrylonitrile
- C08F220/48—Acrylonitrile with nitrogen-containing monomers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
- B01D2325/0283—Pore size
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/18—Membrane materials having mixed charged functional groups
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/30—Chemical resistance
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/38—Hydrophobic membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0006—Organic membrane manufacture by chemical reactions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0081—After-treatment of organic or inorganic membranes
Definitions
- Filtration membranes are useful for purification and separation in the food, beverage, dairy, and pharmaceutical industries.
- Filtration membranes used for separation must overcome three major obstacles: low permeability, fouling, and poor selectivity.
- Membranes with high permeability promote energy savings and cost efficiency.
- Membrane fouling i.e., loss of permeability due to absorption and adhesion of feed components, causes low productivity and high energy use.
- High selectivity very important in every application, depends on membrane pore size.
- This invention is based on an unexpected discovery of certain anti-fouling membranes that have both a high water permeability and a high selectivity.
- One aspect of this invention relates to a statistical copolymer having a molecular weight of 10,000 to 10,000,000 Dalton (e.g., 20,000 to 2,000,000 Dalton and 30,000 to 500,000 Dalton).
- the statistical copolymer contains zwitterionic repeat units and hydrophobic repeat units. Examples include poly((methyl methacrylate)- random-(sulfobetaine methacrylate)), poly((trifluoroethyl methacrylate)-random- (sulfobetaine methacrylate)), poly((acrylonitrile)-random-(sulfobetaine
- the zwitterionic repeat units constituting 25-75% (e.g., 30-75% and 30-70%) by weight of the statistical copolymer, each can contain independently one or more of the following functional groups: sulfobetaine, carboxybetaine, phosphorylcholine, and pyridinium alkyl sulfonate.
- sulfobetaine acrylate can be formed independently from sulfobetaine acrylate, sulfobetaine acrylamide, phosphorylcholine acrylate, phosphorylcholine acrylamide, phosphorylcholine methacrylate, carboxybetaine acrylate, carboxybetaine methacrylate, carboxybetaine acrylamide, 3-(2-vinylpyridinium-l-yl)propane-l- sulfonate, 3-(4-vinylpyridinium-l-yl)propane-l-sulfonate, or sulfobetaine
- the hydrophobic repeat units constituting 25-75% (e.g., 25-70% and 30-70%) by weight of the statistical copolymer, can be formed independently from styrene, fluorinated styrene, methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate. They are capable of forming a homopolymer that has a glass transition temperature of 0 °C or higher (e.g., 25 °C or higher, 50 °C or higher, and 25-250 °C).
- the statistical copolymer of this invention can be synthesized by free radical copolymerization.
- a filtration membrane containing a selective layer formed of a statistical copolymer described above, and, optionally, a support layer.
- This membrane has a molecular weight cut-off of 100 to 10000 Dalton (e.g., 100 to 5000 Dalton and 100 to 2000 Dalton).
- the selective layer contains effective pores (i.e., channels that allow molecules or particles to pass through) formed by self-assembly of the zwitterionic repeat units and having an effective pore size (i.e., the minimum size of molecules or particles rejected by a membrane) of 0.5 to 5 nm (e.g., 0.5-3 nm, 0.5-2.5 nm, 0.6-2 nm, and 0.6-1.5 nm).
- the zwitterionic repeat units form in the selective layer interconnected hydrophilic domains that each have an average diameter of less than 3 nm and provide transport pathways for water.
- the optional support layer on a surface of which the selective layer is disposed, has an effective pore size larger than that of the selective layer and can be formed of polyethersulfone, polyphenylenesulfone, polyphenylenesulfidesulfone, polyacrylonitrile, cellulose ester, polyphenyleneoxide, polypropylene,
- polyvinyledenefluoride polyvinylchloride, polyarylsulfone, polyphenylene sulfone, polyetheretherketone, polysulfone, polyamide, polyimide, or a combination thereof.
- the filtration membrane of this invention has an irreversible flux loss that, after a 24-hour filtration of a foulant with a subsequent water-rinsing, is less than 3%.
- the foulant include a 1000 mg/L bovine serum albumin solution and a 1500 mg/L oil-in-water emulsion.
- the method includes the steps of (i) providing a filtration membrane described above, (ii) placing onto the filtration membrane a solution containing first molecules that have a molecular weight lower than the molecular weight cut-off of the filtration membrane and second molecules that have a molecular weight higher than the molecular weight cut-off of the filtration membrane, and (iii) allowing the first molecules to pass through the filtration membrane, thereby separating the first molecules from the second molecules.
- molecules having a plurality of molecular weights lower than the molecular weight cut-off can be separated simultaneously from those having molecular weights higher than the molecular weight cut-off.
- FIG. 1 includes two scanning electron microscope images of filtration membranes of the present invention.
- FIG. 2 includes two schematic diagrams (2a and 2b) and two transmission electron microscopy images (2c and 2d) of statistical copolymers of the present invention.
- FIG. 3 includes two scanning electron microscope images of PTFEMA-r- SBMA-coated membranes of the present invention.
- FIG. 4 includes a graph showing results from rejection studies on three filtration membranes of the present invention.
- FIG. 5 includes three graphs (5a, 5b, and 5c) showing results from rejection studies on filtration membranes of the present invention and a commercial membrane.
- This invention provides a fouling-resistant filtration membrane that has a high water permeability and a high selectivity.
- This filtration membrane can contain a support layer and a selective layer.
- the support layer providing support for the selective layer, is highly porous and can have a thickness of 10 to 1000 ⁇ (e.g., 15 to 250 ⁇ and 30 to 200 ⁇ ).
- the support layer can be made of any suitable polymer. See J. Mulder, Basic Principles of Membrane Technology (2nd ed.); and Handbook of Industrial
- the support layer can be made of various porous inorganic materials including ceramics (e.g. titanium oxide and aluminum oxide) and metals (e.g. silver).
- the selective layer has a thickness of 0.05 to 50 ⁇ (e.g., 0.05 to 10 ⁇ and 0.05 to 2 ⁇ ). It includes effective pores of 0.5 to 5 nm in size and, typically, is essentially free of effective pores larger than 5 nm. It can be a thin, dense film used as a stand-alone (i.e., unsupported) membrane, e.g., secured on the top of a filter holder. Alternatively, it can be coated onto a porous support layer to form thin film composite membranes by methods well-known in the art (e.g. doctor blade coating and spray coating). The selective layer can also form an integrally skinned membrane, in which the selective layer supported by a porous layer is formed in a single step by common membrane formation methods such as phase inversion.
- the selective layer is formed of a statistical copolymer containing zwitterionic repeat units and hydrophobic repeat units, synthesized by well-known methods (e.g. free radical polymerization). Unlike a block copolymer, a statistical copolymer has repeat units in roughly random order. When containing zwitterionic repeat units, this copolymer resists absorption and adhesion of feed components, and thus avoiding fouling.
- the ratio between the zwitterionic repeat units and the hydrophobic repeat units is important. If the zwitterionic repeat unit content is too low (e.g., 20% or lower), a membrane formed of the copolymer has a low water permeability, as the zwitterionic repeat units are not sufficient to form interconnected domains having effective pores for water to pass through the membrane. On the other hand, if the zwitterionic repeat unit content is too high (and thus the hydrophobic repeat unit content is too low), a membrane formed of the copolymer dissociates in water, as the hydrophobic repeat units do not form a rigid framework to hold the copolymer together.
- the zwitterionic repeat units each contain an equal number of negatively charged functional groups and positively charged functional groups.
- the effective pore size is typically 0.5-5 nm. This is due to strong interactions between the charged groups. When these effective pores are small enough to reject hydrated Na + ions, membranes having such pores are useful for desalination.
- Membranes having larger effective pore sizes can be used to soften water, remove organic compounds above a certain size (e.g. pharmaceuticals) from water, treat wastewater (e.g. textile wastewaters containing dyes), or separate, purify, and exchange solvents (e.g., in the manufacture of pharmaceuticals and
- the hydrophobic repeat units when in homopolymer form, do not dissolve in water and have a glass transition temperature above the operational temperature of the membrane. These repeat units hold the zwitterionic interconnected domains together and stop the copolymer from dissolving in water. Further, they prevent the excessive swelling of the copolymer.
- Membranes made by this method having a high water permeability (e.g. above 10 L/m 2 .h.MPa), are useful for removing salt from water, in applications such as desalination of seawater, wastewater, or brackish water. They are also capable of separating a mixture of two dyes of similar charge but differing molecular size and fractionating two water-soluble organic molecules of different molecular weights.
- Methyl methacrylate was passed through a column of basic activated alumina to remove any inhibitor.
- SBMA dimethyl sulfoxide
- MMA 5 g, 50 mmol
- AIBN azobisisobutyronitrile
- the flask was then kept at 70° C, while stirring at 350 rpm for at least 16 hours, after which, 0.5 g of 4-methoxyphenol (MEHQ) was added to terminate the reaction.
- MEHQ 4-methoxyphenol
- the reaction mixture which was observed to be viscous, was then precipitated in methanol, purified by stirring two fresh portions of methanol for several hours, followed by drying in the vacuum oven overnight.
- the copolymer was determined to contain 32 wt% SBMA, measured by 'H-NMR.
- a membrane was prepared using the polymer described in Example 1 as follows.
- the copolymer (1 g) was dissolved in trifluoroethanol (TFE, 9 ml) at approximately 50°C.
- TFE trifluoroethanol
- the copolymer solution was passed through a 0.45 micrometer syringe filter and degassed in a vacuum oven for at least 2 hours.
- the membranes were prepared by coating a thin layer of copolymer solution on a commercially available PVDF400 ultrafiltration membrane using a doctor blade. After coating, the membrane was immersed in a polar non-solvent bath for 20 minutes, followed by immersion in a water bath.
- a non-solvent in general is a liquid miscible with a copolymer solution and its addition to the copolymer solution results in formation of a polymeric membrane. Either methanol, isopropanol, or acetone was used as a non- solvent. To enhance surface segregation, some of these membranes were annealed in a water bath at 90°C for 2 hours.
- Film thickness and morphology were determined by the examination of freeze-fractured cross-sections of the membranes using a scanning electron microscope (SEM). See Figure 1.
- the flask was then kept at 70° C while stirring at 350 rpm for at least 16 hours, after which 0.5 g of MEHQ was added to terminate the reaction.
- the reaction mixture was observed to be viscous.
- the copolymer was then precipitated in methanol, purified by leaching in two fresh portions of methanol for several hours, followed by drying in the vacuum oven overnight.
- the copolymer was determined to contain 44 wt% SBMA measured by 'H-NMR.
- a membrane was prepared using the copolymer described in Example 3.
- the copolymer (1 g) was dissolved in TFE (9 ml) at approximately 50° C.
- the copolymer solution was passed through a 0.45 micrometer syringe filter and subsequently degassed in a vacuum oven for at least 2 hours.
- the membranes were prepared by coating a thin layer of copolymer solution on a commercially available PAN400 ultrafiltration membrane using a doctor blade. After coating, the membrane was immersed in a polar non-solvent bath for 20 minutes, followed by immersion in a water bath. Either methanol, isopropanol, or acetone was used as a non-solvent. To enhance surface segregation, some of these membranes were annealed in a water bath at 90°C for 2 hours.
- the copolymer used to prepare the membrane in this Example has an SBMA content as high as 44 wt .
- This copolymer is not soluble in commonly used organic solvents except TFE due to its high SBMA content.
- P50, P40, and P30 were PTFEMA-r-SBMA copolymers containing 47 wt .
- Graph 2a shows schematically that a copolymer (left) undergoing self-assembly to form the proposed nanostructure (right), featuring continuous networks of zwitterionic and hydrophobic domains;
- Graph 2b shows the chemical structure of PTFEMA-r-SBMA; and
- Graphs 2c and 2d show TEM images of P50 and P30, respectively.
- a membrane was prepared using the copolymer described in Example 5.
- the copolymer (1 g) was dissolved in TFE (9 ml) at approximately 50°C.
- the copolymer solution was passed through a 0.45 micrometer syringe filter and degassed in a vacuum oven for at least 2 hours.
- the membranes were prepared by coating a thin layer of copolymer solution on a PVDF400 ultrafiltration membrane using a doctor blade. After coating, the membrane was immersed in a polar non- solvent bath for 20 minutes, followed by immersion in a water bath. Either methanol, isopropanol, or acetone was used as a non-solvent. To enhance surface segregation, some of these membranes were annealed in a water bath at 90°C for 2 hours.
- PTFEMA-r-SBMA membranes with varying SBMA contents were prepared from P50, P40, and P30.
- Film thickness and morphology were determined by SEM imaging of freeze- fractured cross-sections of the membranes. See Figure 3.
- Example 6-1 formed using a 50 ⁇ doctor blade gap
- 1 ⁇ formed using a 25 ⁇ doctor blade gap
- the left image shows a membrane, i.e., Sample 6-1, having a selective layer of 6 ⁇
- the right image shows a membrane, i.e., Sample 6-2, having a selective layer of 1 ⁇ . Both selective layers are dense and do not contain large pores.
- EXAMPLE 7 Synthesis of poly((trifluoroethyl methacrylate)-random-(3-(2- vinylpyridinium-l-yl)propane-l -sulfonate)) (PTFEMA-r-SB2VP) and formation of thin film composite membranes from PTFEMA-r- SB2VP
- SB2VP (10 g, 43.9 mmol) was dissolved in 65 ml of TFE in a round bottom flask.
- TFEMA (lOg, 59.5 mmol) was added to the mixture, followed by AIBN (0.01 g). Nitrogen was bubbled for 20 minutes to remove any dissolved oxygen.
- the reaction mixture was placed in an oil bath at 70 °C for at least 16 hours after which 0.5 g of MEHQ was added to terminate the reaction.
- the reaction mixture was first precipitated in ethanol ( ⁇ 1200ml) and then washed twice in deionized water, followed by drying in a vacuum oven overnight.
- the copolymer contained 36 wt SB2VP, measured by ⁇ -NMR using DMSO-d 6 .
- a membrane was subsequently prepared using PTFEMA-r-SB2VP thus synthesized following the procedure described in Example 6.
- EXAMPLE 8 Synthesis of poly((acrylonitrile)-random-(3-(4-vinylpyridinium- l-yl)propane-l -sulfonate)) (PAN-r-SB4VP) and formation of thin film composite membranes from PAN-r-SB4VP
- reaction mixture was first precipitated in ethanol (-1200 ml) and then washed twice in deionized water, followed by drying in a vacuum oven overnight.
- NMR performed in HFIP-d2 (1,1,1, 3,3, 3-hexafluoro-2-propanol ) showed successful copolymerization of PAN-r-SB4VP.
- a membrane was subsequently prepared using PAN-r-SB4VP thus synthesized following the procedure described in Example 6.
- the pure water fluxes through the membranes described in Examples 2, 4, and 6 were measured using an Amicon 8010 stirred, dead-end filtration cell with a cell volume of 10 mL and an effective filtration area of 4.1 cm 2 .
- the cell was stirred at 500 rpm, and the test was performed at 20 psi. After a stabilization period of at least one hour, a sample of the permeate was collected over 10 minutes and weighed. The value obtained was divided by filtration area and experiment time to obtain flux. The flux value was normalized by pressure to obtain pure water permeance. See Table 1 below. Table 1. Water permeance of the three copolymer membranes before and after annealing
- Membranes prepared as described in Examples 2, 4, and 6 were used in studies aimed at identifying their effective pore size, or size cut-off.
- Dye molecules were used in this study.
- the rejection studies were performed on an Amicon 8010 stirred, dead-end filtration cell with a cell volume of 10 mL and an effective filtration area of 4.1 cm 2 .
- the cell was stirred at 500 rpm, and the test was performed at 20 psi.
- the cell was stirred at 500 rpm to minimize concentration polarization effects.
- the cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate was completely clear before switching to a new probe dye.
- Figure 4 shows the rejection of various negatively charged dyes by the membranes made from the three copolymers mentioned in Examples 1, 3, and 5.
- the dye diameter was calculated using the molecular volume values obtained by Molecular Modeling Pro software by ChemSW. Based on the filtration of these anionic dyes, the size cut-off of the membranes is estimated to be between 0.9 and 1.1 nm. Furthermore, the rejection of these dyes is related directly with the molecular size of the dye rather than its charge. See Table 2 below. Thus, these membranes can be used for size-selective separations with unexpectedly high selectivity. Table 2. Molecular size and charge of dyes used in testing the effective pore size, and their rejection by the three membranes described in Example 8
- Graph 5a shows rejection rates of anionic dyes by PTFEMA-r-SBMA membranes with varying SBMA contents, i.e., P50 (47 wt% SBMA), P40 (36 wt% SBMA), and P30 (25 wt SBMA)-coated membranes. All three membranes show a size-based cut-off. The results indicate that the copolymer composition in a filtration membrane does not significantly affect the size-based cut-off.
- Graph 5b shows a comparative study of rejecting charged and neutral dyes between a P50-coated membrane and a commercial PES membrane (PES 1 kDa UF).
- a rejection curve could be plotted for the P50-coated membrane in rejecting dyes, either charged or neutral, indicating a size-based selectivity.
- the commercial PES membrane did not show a size-based selectivity in rejecting dyes as no fitting curve could be plotted.
- Graph 5c shows a comparative study of rejecting anionic dyes between a PTFEMA-r-SBMA membrane and membranes prepared from a pyridine-based copolymer, i.e., PTFEMA-r-SB2VP and PAN-r-SB4VP. All membranes showed essentially similar size cut-off.
- membranes prepared as described in Examples 2, 4, and 6 were used in experiments to determine their salt rejection properties.
- the rejection studies were performed on an Amicon 8010 stirred, dead-end filtration cell with a cell volume of 10 mL and an effective filtration area of 4.1 cm 2 .
- the cell was stirred at 500 rpm, and the test was performed at 20 psi.
- the cell was stirred at 500 rpm to minimize concentration polarization effects.
- After running pure water through the membrane for at least an hour the cell was emptied, and a 200 mg/L solution of magnesium sulfate in water was placed in the cell. After an equilibration period of at least an hour, a sample was collected until enough was obtained for analysis by a standard conductivity probe.
- the cell was rinsed several times with water, and pure water was run through the membrane before switching to other feed solutions.
- MgS0 4 salt rejection was 13%, 17.4%, and 11% by PMMA-r- SBMA (32 wt% SBMA), PTFEMA-r-SBMA (43 wt% SBMA), and PAN-r-SBMA (44 wt% SBMA) respectively.
- DI deionized
- the surface properties of membranes prepared as described in Example 4 was analyzed using a goniometer.
- sessile drop contact angle measurements were performed on unannealed as well as annealed samples. It was observed that the contact angle of the unannealed surface was around 64° whereas that of the annealed sample was around 35°. The unexpectedly much lower contact angle of the latter sample suggested the higher hydrophilicity of the copolymer coating after annealing.
- a membrane that contains any combination of zwitterionic repeat units and hydrophobic repeat units. Further, the ratios and molecular weights of these repeat units can be so engineered to achieve separation of molecules of different molecular weights.
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Abstract
Disclosed is a statistical copolymer that includes both zwitterionic repeat units and hydrophobic repeat units and a filtration membrane that contains a selective layer formed of the statistical copolymer. Also disclosed are methods of preparing the above-described filtration membrane.
Description
ZWITTERION-CONTAINING MEMBRANES
BACKGROUND
Filtration membranes are useful for purification and separation in the food, beverage, dairy, and pharmaceutical industries.
Filtration membranes used for separation must overcome three major obstacles: low permeability, fouling, and poor selectivity. Membranes with high permeability promote energy savings and cost efficiency. Membrane fouling, i.e., loss of permeability due to absorption and adhesion of feed components, causes low productivity and high energy use. High selectivity, very important in every application, depends on membrane pore size.
There is a need to develop a membrane that is highly permeable, selective, and anti-fouling.
SUMMARY
This invention is based on an unexpected discovery of certain anti-fouling membranes that have both a high water permeability and a high selectivity.
One aspect of this invention relates to a statistical copolymer having a molecular weight of 10,000 to 10,000,000 Dalton (e.g., 20,000 to 2,000,000 Dalton and 30,000 to 500,000 Dalton). The statistical copolymer contains zwitterionic repeat units and hydrophobic repeat units. Examples include poly((methyl methacrylate)- random-(sulfobetaine methacrylate)), poly((trifluoroethyl methacrylate)-random- (sulfobetaine methacrylate)), poly((acrylonitrile)-random-(sulfobetaine
methacrylate)),_poly((trifluoroethyl methacrylate)-random-(3-(2-vinylpyridinium-l- yl)propane-l- sulfonate)), and poly((acrylonitrile)-random-(3-(4-vinylpyridinium-l- yl)propane- 1 - sulfonate)) .
The zwitterionic repeat units, constituting 25-75% (e.g., 30-75% and 30-70%) by weight of the statistical copolymer, each can contain independently one or more of the following functional groups: sulfobetaine, carboxybetaine, phosphorylcholine, and pyridinium alkyl sulfonate. They can be formed independently from sulfobetaine acrylate, sulfobetaine acrylamide, phosphorylcholine acrylate, phosphorylcholine acrylamide, phosphorylcholine methacrylate, carboxybetaine acrylate, carboxybetaine methacrylate, carboxybetaine acrylamide, 3-(2-vinylpyridinium-l-yl)propane-l-
sulfonate, 3-(4-vinylpyridinium-l-yl)propane-l-sulfonate, or sulfobetaine
methacrylate.
The hydrophobic repeat units, constituting 25-75% (e.g., 25-70% and 30-70%) by weight of the statistical copolymer, can be formed independently from styrene, fluorinated styrene, methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate. They are capable of forming a homopolymer that has a glass transition temperature of 0 °C or higher (e.g., 25 °C or higher, 50 °C or higher, and 25-250 °C).
The statistical copolymer of this invention can be synthesized by free radical copolymerization.
Another aspect of this invention relates to a filtration membrane containing a selective layer formed of a statistical copolymer described above, and, optionally, a support layer. This membrane has a molecular weight cut-off of 100 to 10000 Dalton (e.g., 100 to 5000 Dalton and 100 to 2000 Dalton). The selective layer contains effective pores (i.e., channels that allow molecules or particles to pass through) formed by self-assembly of the zwitterionic repeat units and having an effective pore size (i.e., the minimum size of molecules or particles rejected by a membrane) of 0.5 to 5 nm (e.g., 0.5-3 nm, 0.5-2.5 nm, 0.6-2 nm, and 0.6-1.5 nm). The zwitterionic repeat units form in the selective layer interconnected hydrophilic domains that each have an average diameter of less than 3 nm and provide transport pathways for water.
The optional support layer, on a surface of which the selective layer is disposed, has an effective pore size larger than that of the selective layer and can be formed of polyethersulfone, polyphenylenesulfone, polyphenylenesulfidesulfone, polyacrylonitrile, cellulose ester, polyphenyleneoxide, polypropylene,
polyvinyledenefluoride, polyvinylchloride, polyarylsulfone, polyphenylene sulfone, polyetheretherketone, polysulfone, polyamide, polyimide, or a combination thereof.
Notably, the filtration membrane of this invention has an irreversible flux loss that, after a 24-hour filtration of a foulant with a subsequent water-rinsing, is less than 3%. Examples of the foulant include a 1000 mg/L bovine serum albumin solution and a 1500 mg/L oil-in-water emulsion.
Still within the scope of this invention is a method of separating molecules of different molecular weights in a solution. The method includes the steps of (i) providing a filtration membrane described above, (ii) placing onto the filtration membrane a solution containing first molecules that have a molecular weight lower than the molecular weight cut-off of the filtration membrane and second molecules
that have a molecular weight higher than the molecular weight cut-off of the filtration membrane, and (iii) allowing the first molecules to pass through the filtration membrane, thereby separating the first molecules from the second molecules. Note that molecules having a plurality of molecular weights lower than the molecular weight cut-off can be separated simultaneously from those having molecular weights higher than the molecular weight cut-off.
The details of one or more embodiments of the invention are set forth in the description and the drawings below. Other features, objects, and advantages of the invention will be apparent from the description, the drawings, and also from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 includes two scanning electron microscope images of filtration membranes of the present invention.
FIG. 2 includes two schematic diagrams (2a and 2b) and two transmission electron microscopy images (2c and 2d) of statistical copolymers of the present invention.
FIG. 3 includes two scanning electron microscope images of PTFEMA-r- SBMA-coated membranes of the present invention.
FIG. 4 includes a graph showing results from rejection studies on three filtration membranes of the present invention.
FIG. 5 includes three graphs (5a, 5b, and 5c) showing results from rejection studies on filtration membranes of the present invention and a commercial membrane.
DETAILED DESCRIPTION
This invention provides a fouling-resistant filtration membrane that has a high water permeability and a high selectivity. This filtration membrane can contain a support layer and a selective layer.
The support layer, providing support for the selective layer, is highly porous and can have a thickness of 10 to 1000 μιη (e.g., 15 to 250 μιη and 30 to 200 μιη).
The support layer can be made of any suitable polymer. See J. Mulder, Basic Principles of Membrane Technology (2nd ed.); and Handbook of Industrial
Membrane Technology (M.C. Porter ed., William Andrew Publishing/Noyes 1990). Examples include polyethersulfone, polyphenylenesulfone,
polyphenylenesulfidesulfone, polyacrylonitrile, cellulose ester, polyphenyleneoxide, polypropylene, polyvinyledenefluoride, polyvinylchloride, polyarylsulfone, polyphenylene sulfone, polyetheretherketone, polysulfone, polyamide, polyimide, and a combination thereof. Alternatively, the support layer can be made of various porous inorganic materials including ceramics (e.g. titanium oxide and aluminum oxide) and metals (e.g. silver).
The selective layer has a thickness of 0.05 to 50 μιη (e.g., 0.05 to 10 μιη and 0.05 to 2 μιη). It includes effective pores of 0.5 to 5 nm in size and, typically, is essentially free of effective pores larger than 5 nm. It can be a thin, dense film used as a stand-alone (i.e., unsupported) membrane, e.g., secured on the top of a filter holder. Alternatively, it can be coated onto a porous support layer to form thin film composite membranes by methods well-known in the art (e.g. doctor blade coating and spray coating). The selective layer can also form an integrally skinned membrane, in which the selective layer supported by a porous layer is formed in a single step by common membrane formation methods such as phase inversion.
As pointed out above, the selective layer is formed of a statistical copolymer containing zwitterionic repeat units and hydrophobic repeat units, synthesized by well-known methods (e.g. free radical polymerization). Unlike a block copolymer, a statistical copolymer has repeat units in roughly random order. When containing zwitterionic repeat units, this copolymer resists absorption and adhesion of feed components, and thus avoiding fouling.
The ratio between the zwitterionic repeat units and the hydrophobic repeat units is important. If the zwitterionic repeat unit content is too low (e.g., 20% or lower), a membrane formed of the copolymer has a low water permeability, as the zwitterionic repeat units are not sufficient to form interconnected domains having effective pores for water to pass through the membrane. On the other hand, if the zwitterionic repeat unit content is too high (and thus the hydrophobic repeat unit content is too low), a membrane formed of the copolymer dissociates in water, as the hydrophobic repeat units do not form a rigid framework to hold the copolymer together.
The zwitterionic repeat units each contain an equal number of negatively charged functional groups and positively charged functional groups. They self- assemble into interconnected domains having effective pores for water permeation. The effective pore size is typically 0.5-5 nm. This is due to strong interactions between the charged groups. When these effective pores are small enough to reject hydrated Na+ ions, membranes having such pores are useful for desalination.
Membranes having larger effective pore sizes can be used to soften water, remove organic compounds above a certain size (e.g. pharmaceuticals) from water, treat wastewater (e.g. textile wastewaters containing dyes), or separate, purify, and exchange solvents (e.g., in the manufacture of pharmaceuticals and
biopharmaceuticals).
The hydrophobic repeat units, when in homopolymer form, do not dissolve in water and have a glass transition temperature above the operational temperature of the membrane. These repeat units hold the zwitterionic interconnected domains together and stop the copolymer from dissolving in water. Further, they prevent the excessive swelling of the copolymer.
Membranes made by this method, having a high water permeability (e.g. above 10 L/m2.h.MPa), are useful for removing salt from water, in applications such as desalination of seawater, wastewater, or brackish water. They are also capable of separating a mixture of two dyes of similar charge but differing molecular size and fractionating two water-soluble organic molecules of different molecular weights.
The specific examples below are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent. All publications cited herein are incorporated by reference in their entirety.
EXAMPLE 1. Synthesis of poly((methyl methacrylate)-random-(sulfobetaine
methacrylate)) (PMMA-r-SBMA)
In this example, statistical copolymer PMMA-r-SBMA was synthesized following the procedures described below.
Methyl methacrylate (MMA) was passed through a column of basic activated alumina to remove any inhibitor. SBMA (5 g, 17.9 mmol) was dissolved in dimethyl sulfoxide (DMSO, 100 ml) in a round bottom flask while stirring at 350 rpm. MMA
(5 g, 50 mmol), and azobisisobutyronitrile (AIBN, 0.01 g) were added to the flask. The flask was sealed with a rubber septum. Nitrogen was bubbled through the reaction mixture for 20 minutes to purge any oxygen dissolved in the mixture. The flask was then kept at 70° C, while stirring at 350 rpm for at least 16 hours, after which, 0.5 g of 4-methoxyphenol (MEHQ) was added to terminate the reaction. The reaction mixture, which was observed to be viscous, was then precipitated in methanol, purified by stirring two fresh portions of methanol for several hours, followed by drying in the vacuum oven overnight. The copolymer was determined to contain 32 wt% SBMA, measured by 'H-NMR.
EXAMPLE 2. Formation of thin film composite membranes from PMMA-r-SBMA
In this example, a membrane was prepared using the polymer described in Example 1 as follows.
The copolymer (1 g) was dissolved in trifluoroethanol (TFE, 9 ml) at approximately 50°C. The copolymer solution was passed through a 0.45 micrometer syringe filter and degassed in a vacuum oven for at least 2 hours. The membranes were prepared by coating a thin layer of copolymer solution on a commercially available PVDF400 ultrafiltration membrane using a doctor blade. After coating, the membrane was immersed in a polar non-solvent bath for 20 minutes, followed by immersion in a water bath. A non-solvent in general is a liquid miscible with a copolymer solution and its addition to the copolymer solution results in formation of a polymeric membrane. Either methanol, isopropanol, or acetone was used as a non- solvent. To enhance surface segregation, some of these membranes were annealed in a water bath at 90°C for 2 hours.
Film thickness and morphology were determined by the examination of freeze-fractured cross-sections of the membranes using a scanning electron microscope (SEM). See Figure 1.
In this figure, two SEM images of the uncoated PVDF400 base membrane (left) and the PMMA-r-SBMA-coated membrane (right) are given at the same magnification. The SEM image of the PMMA-r-SBMA-coated membrane shows a dense coating layer (i.e. having no macroscopic pores) with a thickness of about 5 μιη.
EXAMPLE 3. Synthesis of poly((acrylonitrile)-random-(sulfobetaine methacrylate)) (PAN-r-SBMA)
In this example, statistical copolymer PAN-r-SBMA was synthesized as follows. Acrylonitrile was passed through a column of basic activated alumina to remove any inhibitor. SBMA (4 g, 14.3 mmol) was dissolved in DMSO (100 ml) in a round bottom flask, while stirring at 350 rpm. Acrylonitrile (6 g, 113 mmol), and AIBN (0.01 g) were added to the flask. The flask was sealed with a rubber septum. Nitrogen was bubbled through the reaction mixture for 20 minutes to purge any dissolved oxygen. The flask was then kept at 70° C while stirring at 350 rpm for at least 16 hours, after which 0.5 g of MEHQ was added to terminate the reaction. The reaction mixture was observed to be viscous. The copolymer was then precipitated in methanol, purified by leaching in two fresh portions of methanol for several hours, followed by drying in the vacuum oven overnight. The copolymer was determined to contain 44 wt% SBMA measured by 'H-NMR.
EXAMPLE 4. Formation of thin film composite membranes from PAN-r-SBMA
In this example, a membrane was prepared using the copolymer described in Example 3. The copolymer (1 g) was dissolved in TFE (9 ml) at approximately 50° C. The copolymer solution was passed through a 0.45 micrometer syringe filter and subsequently degassed in a vacuum oven for at least 2 hours. The membranes were prepared by coating a thin layer of copolymer solution on a commercially available PAN400 ultrafiltration membrane using a doctor blade. After coating, the membrane was immersed in a polar non-solvent bath for 20 minutes, followed by immersion in a water bath. Either methanol, isopropanol, or acetone was used as a non-solvent. To enhance surface segregation, some of these membranes were annealed in a water bath at 90°C for 2 hours.
Note that the copolymer used to prepare the membrane in this Example has an SBMA content as high as 44 wt . This copolymer is not soluble in commonly used organic solvents except TFE due to its high SBMA content.
EXAMPLE 5. Synthesis of poly((trifluoro ethyl methacrylate) -random- (sulfobetaine methacrylate)) (PTFEMA-r-SBMA)
In this example, statistical copolymer poly(PTFEMA-r-SBMA) was synthesized as follows. 2,2,2-Trifluoroethyl methacrylate (TFEMA) and SBMA was
passed through a column of basic activated alumina to remove any inhibitor. SBMA (5 g, 17.9 mmol) was dissolved in DMSO (100 ml) in a round bottom flask while stirring at 350 rpm. TFEMA (5 g, 29.7 mmol), SBMA (5 g, 17.9 mmol), and AIBN (0.01 g) were added to the flask. The flask was sealed with a rubber septum.
Nitrogen was bubbled through the reaction mixture for 20 minutes to purge any dissolved oxygen. The flask was then kept at 70° C while stirring at 350 rpm for at least 16 hours, after which, 0.5 g of MEHQ was added to terminate the reaction. The reaction mixture was first precipitated in methanol. Some polymer material was settled at the bottom, but the rest of the solution was still cloudy. The polymer in the bottom was collected separately and purified by stirring two fresh portions of methanol for several hours, followed by drying in the vacuum oven overnight.
Methanol was boiled off from the rest of the cloudy solution, and the solution re- dissolved in DMSO. The solution was further precipitated in a 1 : 1 ratio of methanol and tetrahydrofuran. It was then purified by stirring in methanol for several hours, followed by drying in the vacuum oven overnight. The copolymer was determined to contain 43 wt% SBMA, measured by 'H-NMR.
P50, P40, and P30 were PTFEMA-r-SBMA copolymers containing 47 wt ,
36 wt , and 25 wt SBMA, respectively. The morphology of the self-assembled structure of PTFEMA-r-SBMA copolymers was characterized by transmission electron microscopy (TEM). See Figure 2. In this figure, Graph 2a shows schematically that a copolymer (left) undergoing self-assembly to form the proposed nanostructure (right), featuring continuous networks of zwitterionic and hydrophobic domains; Graph 2b shows the chemical structure of PTFEMA-r-SBMA; and Graphs 2c and 2d show TEM images of P50 and P30, respectively.
The TEM images show that the zwitterionic repeat units formed
interconnected hydrophilic domains in P50 better than in P30 which had an insufficient SBMA content. This finding is supported by the amount of water the copolymers could take up when soaked for 24 hours. Water uptake is closely correlated with the zwitterionic content in copolymers. Namely, P50 and P40 took up
37 and 27 wt of water, while the uptake for P30 was negligible. At a low zwitterion content, water was not able to effectively penetrate the copolymer due to the poor connectivity between the hydrophilic domains formed by zwitterionic repeat units.
EXAMPLE 6. Formation of thin film composite membranes from PTFEMA-r- SBMA
In this example, a membrane was prepared using the copolymer described in Example 5. The copolymer (1 g) was dissolved in TFE (9 ml) at approximately 50°C. The copolymer solution was passed through a 0.45 micrometer syringe filter and degassed in a vacuum oven for at least 2 hours. The membranes were prepared by coating a thin layer of copolymer solution on a PVDF400 ultrafiltration membrane using a doctor blade. After coating, the membrane was immersed in a polar non- solvent bath for 20 minutes, followed by immersion in a water bath. Either methanol, isopropanol, or acetone was used as a non-solvent. To enhance surface segregation, some of these membranes were annealed in a water bath at 90°C for 2 hours.
PTFEMA-r-SBMA membranes with varying SBMA contents were prepared from P50, P40, and P30.
Film thickness and morphology were determined by SEM imaging of freeze- fractured cross-sections of the membranes. See Figure 3.
In this figure, SEM images of two samples of coated membranes with different coating thicknesses are shown. The coating thickness varies between 6 μιη (sample 6-1, formed using a 50 μιη doctor blade gap) and 1 μιη (formed using a 25 μιη doctor blade gap) depending on the doctor blade setting and the selection of non-solvent. Also in this figure, the left image shows a membrane, i.e., Sample 6-1, having a selective layer of 6 μιη and the right image shows a membrane, i.e., Sample 6-2, having a selective layer of 1 μιη. Both selective layers are dense and do not contain large pores.
EXAMPLE 7. Synthesis of poly((trifluoroethyl methacrylate)-random-(3-(2- vinylpyridinium-l-yl)propane-l -sulfonate)) (PTFEMA-r-SB2VP) and formation of thin film composite membranes from PTFEMA-r- SB2VP
In this example, statistical copolymer PTFEMA-r-SB2VP was synthesized as follows. Pyridine-based zwitterionic molecules including 3-(2-vinylpyridinium-l- yl)propane-l- sulfonate (SB2VP) were first prepared according to the procedure described in Purdy and Kuyinu, Polymer Preprints (2009) 50(2), 677-678.
SB2VP (10 g, 43.9 mmol) was dissolved in 65 ml of TFE in a round bottom flask. TFEMA (lOg, 59.5 mmol) was added to the mixture, followed by AIBN (0.01 g). Nitrogen was bubbled for 20 minutes to remove any dissolved oxygen. The
reaction mixture was placed in an oil bath at 70 °C for at least 16 hours after which 0.5 g of MEHQ was added to terminate the reaction. The reaction mixture was first precipitated in ethanol (~ 1200ml) and then washed twice in deionized water, followed by drying in a vacuum oven overnight. The copolymer contained 36 wt SB2VP, measured by Ή-NMR using DMSO-d6.
A membrane was subsequently prepared using PTFEMA-r-SB2VP thus synthesized following the procedure described in Example 6.
EXAMPLE 8. Synthesis of poly((acrylonitrile)-random-(3-(4-vinylpyridinium- l-yl)propane-l -sulfonate)) (PAN-r-SB4VP) and formation of thin film composite membranes from PAN-r-SB4VP
In this example, statistical copolymer PAN-r-SB4VP was synthesized as follows. 3-(4-vinylpyridinium-l-yl)propane-l-sulfonate (SB4VP) (10 g, 43.9 mmol) was dissolved in 65 ml of TFE in a round bottom flask. AN (10 g, 0.19 mol) was added to the mixture, followed by AIBN (0.01 g). Nitrogen was bubbled for 20 minutes to remove any dissolved oxygen. The reaction mixture was placed in an oil bath at 70 °C for at least 16 hours after which 0.5 g of MEHQ was added to terminate the reaction. The reaction mixture was first precipitated in ethanol (-1200 ml) and then washed twice in deionized water, followed by drying in a vacuum oven overnight. NMR performed in HFIP-d2 (1,1,1, 3,3, 3-hexafluoro-2-propanol ) showed successful copolymerization of PAN-r-SB4VP.
A membrane was subsequently prepared using PAN-r-SB4VP thus synthesized following the procedure described in Example 6.
EXAMPLE 9. Water permeability of SBMA copolymer membranes
In this example, the pure water fluxes through the membranes described in Examples 2, 4, and 6 (Sample 6-1) were measured using an Amicon 8010 stirred, dead-end filtration cell with a cell volume of 10 mL and an effective filtration area of 4.1 cm2. The cell was stirred at 500 rpm, and the test was performed at 20 psi. After a stabilization period of at least one hour, a sample of the permeate was collected over 10 minutes and weighed. The value obtained was divided by filtration area and experiment time to obtain flux. The flux value was normalized by pressure to obtain pure water permeance. See Table 1 below.
Table 1. Water permeance of the three copolymer membranes before and after annealing
The experiment was performed on both as-cast membranes, and on membranes that were annealed in water at 90°C for 2 hours. Unexpectedly, high permeabilities were achieved with these membranes, despite the thick coatings, which were as thick as 6 μιη.
EXAMPLE 10. Dye rejection by SBMA copolymer membranes
Membranes prepared as described in Examples 2, 4, and 6 (Sample 6-1) were used in studies aimed at identifying their effective pore size, or size cut-off.
Dye molecules were used in this study. The rejection studies were performed on an Amicon 8010 stirred, dead-end filtration cell with a cell volume of 10 mL and an effective filtration area of 4.1 cm2. The cell was stirred at 500 rpm, and the test was performed at 20 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After running pure water through the membrane for at least an hour, the cell was emptied, and a 100 mg/L solution of the probe dye in water was placed in the cell. After an equilibration period of at least an hour, a sample was collected until enough was obtained for analysis by UV- Visible spectrophotometry. The cell was rinsed several times with water. Pure water was filtered through the membrane until the permeate was completely clear before switching to a new probe dye. Figure 4 shows the rejection of various negatively charged dyes by the membranes made from the three copolymers mentioned in Examples 1, 3, and 5.
The dye diameter was calculated using the molecular volume values obtained by Molecular Modeling Pro software by ChemSW. Based on the filtration of these
anionic dyes, the size cut-off of the membranes is estimated to be between 0.9 and 1.1 nm. Furthermore, the rejection of these dyes is related directly with the molecular size of the dye rather than its charge. See Table 2 below. Thus, these membranes can be used for size-selective separations with unexpectedly high selectivity. Table 2. Molecular size and charge of dyes used in testing the effective pore size, and their rejection by the three membranes described in Example 8
a: The assay was not performed.
EXAMPLE 11. Dye rejection by statistical copolymer membranes and a commercial membrane
In this example, a commercial membrane and membranes prepared as described in Examples 6, 7, and 8 were used in experiments aimed at identifying their effective pore size or size cut-off.
Three rejection studies were performed according to the procedure described in Example 10. The results are shown in Figure 5.
Graph 5a shows rejection rates of anionic dyes by PTFEMA-r-SBMA membranes with varying SBMA contents, i.e., P50 (47 wt% SBMA), P40 (36 wt% SBMA), and P30 (25 wt SBMA)-coated membranes. All three membranes show a size-based cut-off. The results indicate that the copolymer composition in a filtration membrane does not significantly affect the size-based cut-off. Graph 5b shows a comparative study of rejecting charged and neutral dyes between a P50-coated membrane and a commercial PES membrane (PES 1 kDa UF). A rejection curve could be plotted for the P50-coated membrane in rejecting dyes, either charged or
neutral, indicating a size-based selectivity. By contrast, the commercial PES membrane did not show a size-based selectivity in rejecting dyes as no fitting curve could be plotted. Finally, Graph 5c shows a comparative study of rejecting anionic dyes between a PTFEMA-r-SBMA membrane and membranes prepared from a pyridine-based copolymer, i.e., PTFEMA-r-SB2VP and PAN-r-SB4VP. All membranes showed essentially similar size cut-off.
EXAMPLE 12. Salt rejection by SBMA copolymer membranes
In this example, membranes prepared as described in Examples 2, 4, and 6 (Sample 6-1) were used in experiments to determine their salt rejection properties. The rejection studies were performed on an Amicon 8010 stirred, dead-end filtration cell with a cell volume of 10 mL and an effective filtration area of 4.1 cm2. The cell was stirred at 500 rpm, and the test was performed at 20 psi. The cell was stirred at 500 rpm to minimize concentration polarization effects. After running pure water through the membrane for at least an hour, the cell was emptied, and a 200 mg/L solution of magnesium sulfate in water was placed in the cell. After an equilibration period of at least an hour, a sample was collected until enough was obtained for analysis by a standard conductivity probe. The cell was rinsed several times with water, and pure water was run through the membrane before switching to other feed solutions.
Unexpectedly, MgS04 salt rejection was 13%, 17.4%, and 11% by PMMA-r- SBMA (32 wt% SBMA), PTFEMA-r-SBMA (43 wt% SBMA), and PAN-r-SBMA (44 wt% SBMA) respectively.
EXAMPLE 13. Anti-fouling properties of SBMA copolymer membranes
In this study, either a 1000 mg/L bovine serum albumin solution or a 1500 mg/L oil-in- water emulsion was used as a foulant to test the fouling resistance of a
PTFEMA-r-SBMA membrane.
The study was conducted as follows. First, deionized (DI) water was filtered through a membrane until its stabilized flux was measured. Next, the membrane was used in filtration of a foulant solution. After 24 hours, the membrane was rinsed with
DI water followed by a test to determine its flux loss. A commercial PES membrane was used as a control.
When a 1000 mg/L bovine serum albumin solution was used as a foulant, a tested P40-coated membrane showed only a small decline in its flux (7% over 24 hours). The flux was fully recovered (>99 ) after the membrane was water- rinsed. By contrast, the commercial PES membrane exhibited a flux decline of 41%, which was not recovered after a water rinse.
Similar results were obtained from a study using a 1500 mg/L oil-in- water emulsion as a foulant. A tested P50-coated membrane exhibited exceptional fouling resistance. The flux decline was only 4% and was completely recovered after rinsing with water. In the same study, a commercial PES membrane lost 88% of its flux irreversibly.
EXAMPLE 14. Contact Angle of PAN- r- SB MA Surfaces
In this example, the surface properties of membranes prepared as described in Example 4 was analyzed using a goniometer. As an indicator of the hydrophilicity of the materials, sessile drop contact angle measurements were performed on unannealed as well as annealed samples. It was observed that the contact angle of the unannealed surface was around 64° whereas that of the annealed sample was around 35°. The unexpectedly much lower contact angle of the latter sample suggested the higher hydrophilicity of the copolymer coating after annealing.
OTHER EMBODIMENTS
All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.
Indeed, to achieve the purpose of purification and separation, one skilled in the art can design a membrane that contains any combination of zwitterionic repeat units and hydrophobic repeat units. Further, the ratios and molecular weights of these repeat units can be so engineered to achieve separation of molecules of different molecular weights.
From the above description, a skilled artisan can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it
to various usages and conditions. Thus, other embodiments are also within the claims.
Claims
1. A statistical copolymer comprising
zwitterionic repeat units, each containing independently sulfobetaine, carboxybetaine, or pyridinium alkyl sulfonate, and
hydrophobic repeat units, each formed independently from styrene, fluorinated styrene, methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate, wherein the statistical copolymer has a molecular weight
of 10,000 to 10,000,000 Dalton, the zwitterionic repeat units and the hydrophobic repeat units each constitute 25-75% by weight of the statistical copolymer, and the hydrophobic repeat units are capable of forming a homopolymer that has a glass transition temperature of 0 °C or higher.
2. The statistical copolymer of claim 1 , wherein the statistical copolymer has a molecular weight of 20,000 to 2,000,000 Dalton, the zwitterionic repeat units constitute 30-75% by weight of the statistical copolymer, and the hydrophobic repeat units constitute 25-70% by weight of the statistical copolymer.
3. The statistical copolymer of claim 2, wherein the statistical copolymer has a molecular weight of 30,000 to 500,000 Dalton, the zwitterionic repeat units constitute 30-70% by weight of the statistical copolymer, and the hydrophobic repeat units constitute 30-70% by weight of the statistical copolymer.
4. The statistical copolymer of claim 1 , wherein the zwitterionic repeat units each are formed independently from sulfobetaine acrylate, sulfobetaine acrylamide, carboxybetaine acrylate, carboxybetaine methacrylate, carboxybetaine acrylamide, 3- (2- vinylpyridinium- 1 -yl)propane- 1 -sulfonate, 3 -(4- vinylpyridinium- 1 -yl)propane- 1 - sulfonate, or sulfobetaine methacrylate; and the hydrophobic repeat units each are formed independently from methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate.
5. The statistical copolymer of claim 4, wherein the statistical copolymer has a molecular weight of 20,000 to 2,000,000 Dalton, the zwitterionic repeat units constitute 30-75% by weight of the statistical copolymer, and the hydrophobic repeat units constitute 25-70% by weight of the statistical copolymer.
6. The statistical copolymer of claim 5, wherein the statistical copolymer has a molecular weight of 30,000 to 500,000 Dalton, the zwitterionic repeat units constitute 30-70% by weight of the statistical copolymer, and the hydrophobic repeat units constitute 30-70% by weight of the statistical copolymer.
7. The statistical copolymer of claim 1, wherein the statistical copolymer is poly((methyl methacrylate)-random-(sulfobetaine methacrylate)).
8. The statistical copolymer of claim 1, wherein the statistical copolymer is poly ((trifluoroethyl methacrylate) -random- (sulf obetaine methacrylate)) .
9. The statistical copolymer of claim 1, wherein the statistical copolymer is poly((acrylonitrile)-random-(sulfobetaine methacrylate)).
10. The statistical copolymer of claim 1, wherein the statistical copolymer is poly((trifluoroethyl methacrylate)-random-(3-(2-vinylpyridinium-l-yl)propane-l- sulfonate)).
11. The statistical copolymer of claim 1 , wherein the statistical copolymer is poly((acrylonitrile)-random-(3-(4-vinylpyridinium-l-yl)propane-l -sulfonate)).
12. The statistical copolymer of claim 1, wherein the statistical copolymer has a molecular weight of 20,000 to 2,000,000 Dalton, the zwitterionic repeat units constitute 30-75% by weight of the statistical copolymer, the hydrophobic repeat units constitute 25-70% by weight of the statistical copolymer, and the glass transition temperature is 25 °C or higher.
13. The statistical copolymer of claim 12, wherein the statistical copolymer has a molecular weight of 30,000 to 500,000 Dalton, the zwitterionic repeat units constitute 30-70% by weight of the statistical copolymer, the hydrophobic repeat units constitute 30-70% by weight of the statistical copolymer, and the glass transition temperature is 25 °C or higher.
14. A filtration membrane comprising a selective layer formed of a statistical copolymer comprising zwitterionic repeat units and hydrophobic repeat units, wherein the filtration membrane has a molecular weight cut-off of 100 to 10000 Dalton, the selective layer contains effective pores formed by self-assembly of the zwitterionic repeat units and having effective pore sizes of 0.5 to 3 nm, and the statistical copolymer has a molecular weight of 10,000 to 10,000,000 Dalton, the zwitterionic repeat units and the hydrophobic repeat units each constituting 25-75% by weight of the statistical copolymer, and the hydrophobic repeat units being capable of forming a homopolymer that has a glass transition temperature of 0 °C or higher.
15. The filtration membrane of claim 14, wherein the zwitterionic repeat units each contain independently sulfobetaine, carboxybetaine, phosphorylcholine, or pyridinium alkyl sulfonate; and the hydrophobic repeat units each are formed independently from styrene, fluorinated styrene, methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate.
16. The filtration membrane of claim 15, wherein the statistical copolymer has a molecular weight of 20,000 to 2,000,000 Dalton, the zwitterionic repeat units constitute 30-75% by weight of the statistical copolymer, the hydrophobic repeat units constitute 25-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2.5 nm.
17. The filtration membrane of claim 16, wherein the statistical copolymer has a molecular weight of 30,000 to 500,000 Dalton, the zwitterionic repeat units constitute 30-70% by weight of the statistical copolymer, the hydrophobic repeat units constitute 30-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2 nm.
18. The filtration membrane of claim 15, wherein the zwitterionic repeat units each are formed independently from sulfobetaine acrylate, sulfobetaine acrylamide, phosphorylcholine acrylate, phosphorylcholine acrylamide, phosphorylcholine methacrylate, carboxybetaine acrylate, carboxybetaine methacrylate, carboxybetaine acrylamide, 3 -(2- vinylpyridinium- 1 -yl)propane- 1 -sulfonate, 3 -(4- vinylpyridinium- 1 - yl)propane-l- sulfonate, or sulfobetaine methacrylate; and the hydrophobic repeat
units each are formed independently from methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate.
19. The filtration membrane of claim 18, wherein the statistical copolymer has a molecular weight of 20,000 to 2,000,000 Dalton, the zwitterionic repeat units constitute 30-75% by weight of the statistical copolymer, the hydrophobic repeat units constitute 25-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2.5 nm.
20. The filtration membrane of claim 18, wherein the statistical copolymer has a molecular weight of 30,000 to 500,000 Dalton, the zwitterionic repeat units constitute 30-70% by weight of the statistical copolymer, the hydrophobic repeat units constitute 30-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2 nm.
21. The filtration membrane of claim 14, further comprising a support layer, wherein the selective layer is disposed on a surface of the support layer and the support layer has an effective pore size larger than that of the selective layer and is formed of polyethersulfone, polyphenylenesulfone, polyphenylenesulfidesulfone, polyacrylonitrile, cellulose ester, polyphenyleneoxide, polypropylene,
polyvinyledenefluoride, polyvinylchloride, polyarylsulfone, polyphenylene sulfone, polyetheretherketone, polysulfone, polyamide, polyimide, or a combination thereof.
22. The filtration membrane of claim 21, wherein the zwitterionic repeat units each contain independently sulfobetaine, carboxybetaine, phosphorylcholine, or pyridinium alkyl sulfonate; and the hydrophobic repeat units each are formed independently from styrene, fluorinated styrene, methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate.
23. The filtration membrane of claim 22, wherein the statistical copolymer has a molecular weight of 20,000 to 2,000,000 Dalton, the zwitterionic repeat units constitute 30-75% by weight of the statistical copolymer, the hydrophobic repeat units constitute 25-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2.5 nm.
24. The filtration membrane of claim 23, wherein the statistical copolymer has a molecular weight of 30,000 to 500,000 Dalton, the zwitterionic repeat units constitute 30-70% by weight of the statistical copolymer, the hydrophobic repeat units constitute 30-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2 nm.
25. The filtration membrane of claim 22, wherein the zwitterionic repeat units each are formed independently from sulfobetaine acrylate, sulfobetaine acrylamide, phosphorylcholine acrylate, phosphorylcholine acrylamide, phosphorylcholine methacrylate, carboxybetaine acrylate, carboxybetaine methacrylate, carboxybetaine acrylamide, 3 -(2- vinylpyridinium- 1 -yl)propane- 1 -sulfonate, 3 -(4- vinylpyridinium- 1 - yl)propane-l- sulfonate, or sulfobetaine methacrylate; and the hydrophobic repeat units each are formed independently from methyl methacrylate, acrylonitrile, or trifluoroethyl methacrylate.
26. The filtration membrane of claim 25, wherein the statistical copolymer has a molecular weight of 20,000 to 2,000,000 Dalton, the zwitterionic repeat units constitute 30-75% by weight of the statistical copolymer, the hydrophobic repeat units constitute 25-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2.5 nm.
27. The filtration membrane of claim 26, wherein the statistical copolymer has a molecular weight of 30,000 to 500,000 Dalton, the zwitterionic repeat units constitute 30-70% by weight of the statistical copolymer, the hydrophobic repeat units constitute 30-70% by weight of the statistical copolymer, and the effective pore size is 0.5 to 2 nm.
28. A method of separating molecules in a solution, the method comprising: providing a filtration membrane of claim 14;
placing onto the filtration membrane a solution containing first molecules that have a molecular weight lower than the molecular weight cut-off of the filtration membrane and second molecules that have a molecular weight higher than the molecular weight cut-off of the filtration membrane; and
allowing the first molecules to pass through the filtration membrane, thereby separating the first molecules from the second molecules.
29. The filtration membrane of claim 14, wherein the zwitterionic repeat units form interconnected hydrophilic domains each having an average diameter of less than 3 nm, the hydrophilic domains providing transport pathways for water.
30. The filtration membrane of claim 14, wherein an irreversible flux loss for the filtration membrane after a 24-hour filtration of a foulant with a subsequent water- rinsing is less than 3%, the foulant being either a 1000 mg/L bovine serum albumin solution or a 1500 mg/L oil-in- water emulsion.
31. The filtration membrane of claim 14, wherein the statistical copolymer is synthesized by free radical copolymerization.
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US20150328597A1 (en) * | 2014-05-16 | 2015-11-19 | General Electric Company | Zwitterion-functionalized block copolymer membranes and associated block copolymer composition |
WO2018085057A1 (en) * | 2016-11-02 | 2018-05-11 | Trustees Of Tufts College | Fabrication of filtration membranes |
US20180133656A1 (en) * | 2015-06-01 | 2018-05-17 | Trustees Of Tufts College | Zwitterionic fiber membranes |
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US10851241B2 (en) | 2014-11-19 | 2020-12-01 | Cytiva Sweden Ab | Zwitterion-functionalized multicomponent copolymers and associated polymer blends and membranes |
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070185264A1 (en) * | 2004-10-26 | 2007-08-09 | Yonksok Seo | Polymeric composite separation membrane |
WO2011088505A1 (en) * | 2010-01-19 | 2011-07-28 | Flinders University Of South Australia | Low-fouling filtration membranes |
US20110305872A1 (en) * | 2010-06-09 | 2011-12-15 | Jun Li | Non-fouling, anti-microbial, anti-thrombogenic graft-from compositons |
US20130165538A1 (en) * | 2010-01-09 | 2013-06-27 | Dais Analytic Corporation | Anionic exchange electrolyte polymer membranes |
US8550256B1 (en) * | 2012-07-27 | 2013-10-08 | International Business Machines Corporation | Filtration membrane with covalently grafted fouling-resistant polymer |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3473998A (en) * | 1963-08-07 | 1969-10-21 | Du Pont | Sulfobetaine monomers,polymers thereof and composite filaments prepared from said polymers |
US7803867B2 (en) * | 2005-05-19 | 2010-09-28 | Arkema Inc. | Highly weatherable roof coatings containing aqueous fluoropolymer dispersions |
US20080312349A1 (en) * | 2007-02-22 | 2008-12-18 | General Electric Company | Method of making and using membrane |
CN101808977A (en) * | 2007-08-30 | 2010-08-18 | 阿尔比马尔公司 | Preparation of 2-(1,3-dimethylbutyl)aniline and other branched alkyl-substituted-anilines |
US7732533B2 (en) | 2007-08-31 | 2010-06-08 | Micron Technology, Inc. | Zwitterionic block copolymers and methods |
US7985339B2 (en) | 2008-08-25 | 2011-07-26 | General Electric Company | Polyarylether compositions bearing zwitterion functionalities |
CN102906127A (en) | 2009-11-06 | 2013-01-30 | 华盛顿大学商业中心 | Self-assembled particles from zwitterionic polymers and related methods |
US8299147B2 (en) * | 2009-12-11 | 2012-10-30 | Perfect Defense Technology Co., Ltd. | Chemical resistant ionomers and protective coverings |
US8288472B2 (en) * | 2009-12-29 | 2012-10-16 | Chung-Yuan Christian University | Antibiofouling nonionic-zwitterionic copolymer |
JP2011175701A (en) | 2010-02-24 | 2011-09-08 | Hitachi-Lg Data Storage Inc | Optical disk drive and method for controlling the same |
WO2013023006A2 (en) | 2011-08-08 | 2013-02-14 | California Institute Of Technology | Filtration membranes, and related nano and/or micro fibers, composites, methods and systems |
WO2015070004A1 (en) * | 2013-11-08 | 2015-05-14 | Tufts University | Zwitterion-containing membranes |
WO2016109621A1 (en) * | 2014-12-30 | 2016-07-07 | Tufts University | Zwitterionic copolymers for fouling resistant filtration membranes |
CN106921377B (en) * | 2015-12-24 | 2020-06-02 | 小米科技有限责任公司 | Touch key module, key icon display method and device |
-
2014
- 2014-11-07 WO PCT/US2014/064528 patent/WO2015070004A1/en active Application Filing
- 2014-11-07 US US15/034,454 patent/US10150088B2/en active Active
-
2020
- 2020-03-16 US US16/820,125 patent/US11421061B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070185264A1 (en) * | 2004-10-26 | 2007-08-09 | Yonksok Seo | Polymeric composite separation membrane |
US20130165538A1 (en) * | 2010-01-09 | 2013-06-27 | Dais Analytic Corporation | Anionic exchange electrolyte polymer membranes |
WO2011088505A1 (en) * | 2010-01-19 | 2011-07-28 | Flinders University Of South Australia | Low-fouling filtration membranes |
US20110305872A1 (en) * | 2010-06-09 | 2011-12-15 | Jun Li | Non-fouling, anti-microbial, anti-thrombogenic graft-from compositons |
US8550256B1 (en) * | 2012-07-27 | 2013-10-08 | International Business Machines Corporation | Filtration membrane with covalently grafted fouling-resistant polymer |
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US9440198B2 (en) * | 2014-05-16 | 2016-09-13 | General Electric Company | Zwitterion-functionalized block copolymer membranes and associated block copolymer composition |
US20150328597A1 (en) * | 2014-05-16 | 2015-11-19 | General Electric Company | Zwitterion-functionalized block copolymer membranes and associated block copolymer composition |
US11407897B2 (en) | 2014-11-19 | 2022-08-09 | Cytiva Sweden Ab | Zwitterion-functionalized multicomponent copolymers and associated polymer blends and membranes |
US10851241B2 (en) | 2014-11-19 | 2020-12-01 | Cytiva Sweden Ab | Zwitterion-functionalized multicomponent copolymers and associated polymer blends and membranes |
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CN109862959A (en) * | 2016-11-02 | 2019-06-07 | 塔夫茨大学信托人 | The preparation of filter membrane |
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Also Published As
Publication number | Publication date |
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US20210039054A1 (en) | 2021-02-11 |
US11421061B2 (en) | 2022-08-23 |
US20160303523A1 (en) | 2016-10-20 |
US10150088B2 (en) | 2018-12-11 |
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