METAL-ORGANIC FRAMEWORK SUPPORTED ON POROUS POLYMER

• US 20130313193A1
• Filed: 05/20/2013
• Published: 11/28/2013
• Est. Priority Date: 05/25/2012
• Status: Active Grant

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Nair, Sankar, Brown, Andrew, Jones, Christopher W.
• Granted Patent: US 9,375,678 B2
• Time in Patent Office: Days
• US Class Current: 210/650
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 67/0051 by controlled crystallisation, e,.g. hydrothermal growth
• CPC Class Codes: B01D 67/00793 Dispersing a component, e.g. as particles or powder, in another component
• CPC Class Codes: B01D 69/148 Organic/inorganic mixed matrix membranes
• CPC Class Codes: B01D 71/028 Molecular sieves carbon B01D71/021
• CPC Class Codes: B01D 71/0281 Zeolites
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

The growth of continuous MOF membranes on porous polymeric supports is reported, wherein a dip-coating procedure is used to deposit a layer of seed MOF nanocrystals on the surfaces of porous polymers, preferably in the form of hollow fibers, and polycrystalline MOF membranes are subsequently grown at temperatures as low as 65° C. from precursor solutions. The present work opens the road to inexpensive and scalable fabrication of MOF membranes for large-scale separation applications.

Claims

1. A method of preparing MOF-membrane-polymer, comprising:

a) dip-coating a porous polymer with a seed solution comprising MOF nanocrystals of average size<

1 micron suspended in a first solvent that can penetrate the porous polymer;

b) drying the dip coated porous polymer;

c) growing larger MOF crystals on the dip-coated porous polymer at less than 100°

C. in a growth solution to make a MOF-membrane-polymer, the growth solution comprising MOF precursors solubilized in a second solvent; and

d) rinsing and drying the MOF-membrane-polymer.

2. The method of claim 1, wherein the porous polymer is in the shape of a film, a fiber or a hollow fiber.

3. The method of claim 1, wherein each of the first solvent and the second solvent is independently selected from the group consisting of water, methanol, ethanol, propanol, butanol, chloroform, toluene, hexane, dimethylformamide (DMF), and combinations thereof, with the proviso that each of the first solvent and the second solvent does not solubilize the porous polymer.

4. The method of claim 1, wherein the MOF is a ZIF and each of the first solvent and the second solvent is an alcohol independently selected from the group consisting of methanol, ethanol, propanol, butanol, and combinations thereof, with the proviso that each of the first solvent and second solvent does not solubilize the porous polymer.

5. The method of claim 1, wherein the seed solution comprises 0.1-1% ZIF nanocrystals in methanol.

6. The method of claim 1, wherein the seed solution comprises 0.4% ZIF nanocrystals in methanol.

7. The method of claim 4, wherein the growth solution comprises 0.5-1.0% of ligand and 0.5-1.0% zinc in methanol.

8. The method of claim 1, wherein the growth solution comprises 0.5-1.0% of imidizole carboxyaldehyde and 0.15-1.0% zinc (II) nitrate in methanol.

9. The method of claim 1, wherein the seed solution comprises 0.1-1% ZIF nanocrystals in ethanol.

10. The method of claim 1, wherein the seed solution comprises 0.4% ZIF nanocrystals in ethanol.

11. The method of claim 1, wherein the MOF nanocrystals are of average size 200-600 nm.

12. The method of claim 1, wherein the MOF nanocrystals are of average size 400 nm.

13. The method of claim 4, wherein the ZIF nanocrystals are of average size 400 nm.

14. The method of claim 1, wherein the porous polymer is selected from the group consisting of polysulfone (PS), polyethylene (PE), polyacrilonitrile (PAN), polyethersulfone (PES), polyetherimide (PEI), poly(amide-imide) (PAI), polyvinylidene difluoride (PVDF), polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), poly(3-octylthiophene) (POT), poly(3-(2-acetoxyethylthiophene) (PAET), polyimide, polyamide, polyetheretherketones (PEEK), and poly(vinyl acetate) (PVAc), polypropylene, cellulose acetate, 2,2-bis(3,4-carboxyphenyl)hexafluoropropane dianhydride—

diaminomesitylene) (6FDA-DAM) and derivatives thereof.

15. The method of claim 1, wherein the porous polymer comprises poly(amide-imide).

16. The method of claim 1, wherein the porous polymer is shaped as a hollow tube.

17. The method of claim 1, wherein the porous polymer is shaped as a hollow tube and the ends are sealed before step a).

18. The method of claim 1, wherein the growing step occurs at 60-70°

C.

19. The method of claim 1, wherein the growing step occurs at 65°

C.

20. The method of claim 4, wherein the ZIF is ZIF-90.

21. The method of claim 4, wherein the ZIF is ZIF-8.

26. A filter, comprising the MOF polymer membrane of claim 1.

28. A method of separating CO₂ from a mixture of gases, comprising:

a) applying a mixture of gases including CO₂ to the MOF polymer membrane of claim 1, and

b) separating the CO₂ from the remaining mixture of gases.

29. A method of separating a chemical from a mixture of chemicals, comprising:

a) applying a mixture of chemicals to the MOF polymer membrane of claim 1; and

b) separating a chemical from the remaining mixture of chemicals.

22. A method of preparing ZIF membranes on polymeric supports, comprising:

a) dip-coating a porous polymer using a seed solution comprising 0.1-1% ZIF nanocrystals of average size<

0.5 micron suspended in an alcohol that can penetrate the porous polymer;

b) drying the dip-coated porous polymer;

c) growing larger ZIF crystals on the dip-coated porous polymer at less than 100°

C. in a growth solution comprising alcohol and 0.1-2% ZIF precursors to make a ZIF membrane; and

d) rinsing and drying the ZIF membrane.

23. The method of claim 22, wherein the ZIF is ZIF-90 and the ZIF precursors are imidizole carboxyaldehyde and zinc (II) nitrate.

24. The method of claim 22, wherein the ZIF is ZIF-8 and the ZIF precursors are 2-methylimidazole and zinc (II) nitrate.

25. The method of claim 22, wherein the porous polymer is selected from the group consisting of polysulfone (PS), polyethylene (PE), polyacrilonitrile (PAN), polyethersulfone (PES), polyetherimide (PEI), poly(amide-imide) (PAI), polyvinylidene difluoride (PVDF), polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), poly(3-octylthiophene) (POT), poly(3-(2-acetoxyethylthiophene) (PAET), polyimide, polyamide, polyetheretherketones (PEEK), and poly(vinyl acetate) (PVAc), polypropylene, cellulose acetate, 2,2-bis(3,4-carboxyphenyl)hexafluoropropane dianhydride—

diaminomesitylene) (6FDA-DAM), and derivatives thereof.

27. A filter, comprising the ZIF membrane of claim 22.

30. A method of seed coating porous polymeric supports, comprising:

a) dip-coating a porous polymer with a seed solution comprising MOF nanocrystals of average size<

1 micron suspended in a first solvent that can penetrate the porous polymer; and

b) drying the dip-coated fiber.

31. The method of claim 30, wherein the MOF is a ZIF and the first solvent is an alcohol selected from the group consisting of water, methanol, ethanol, propanol, butanol and combinations thereof.

32. The method of claim 30, wherein the seed solution comprises 0.1-1% ZIF nanocrystals in methanol.

33. A method of growing MOF crystals on a MOF seeded porous polymer, comprising:

a) growing larger MOF crystals on a MOF seeded porous polymer at less than 100°

C. in a growth solution to make a MOF-membrane-polymer, the growth solution comprising MOF precursors solubilized in a second solvent; and

b) rinsing and drying the MOF-membrane-polymer.

34. The method of claim 33, wherein the MOF is a ZIF and the second solvent is an alcohol selected from the group consisting of methanol, ethanol, propanol, butanol, and combinations thereof.

35. The method of claim 33, wherein the porous polymer is selected from the group consisting of polysulfone (PS), polyethylene (PE), polyacrilonitrile (PAN), polyethersulfone (PES), polyetherimide (PEI), poly(amide-imide) (PAI), polyvinylidene difluoride (PVDF), polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), poly(3-octylthiophene) (POT), poly(3-(2-acetoxyethylthiophene) (PAET), polyimide, polyamide, polyetheretherketones (PEEK), and poly(vinyl acetate) (PVAc), polypropylene, cellulose acetate, 2,2-bis(3,4-carboxyphenyl)hexafluoropropane dianhydride—

diaminomesitylene) (6FDA-DAM), and derivatives thereof.