Methods to Enhance Separation Performance of Metal-Organic Framework Membranes

• US 20180001275A1
• Filed: 09/14/2017
• Published: 01/04/2018
• Est. Priority Date: 03/04/2014
• Status: Active Grant

• Current Assignee: Texas A&M University System
• Original Assignee: Texas A&M University System
• Inventors: Jeong, Hae-Kwon, Kwon, Hyuk Taek
• Granted Patent: US 10,639,593 B2
• Time in Patent Office: Days
• CPC Class Codes: B01D 2325/02 Details relating to pores or porosity of the membranes
• CPC Class Codes: B01D 2325/0283 Pore size
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/12 Composite membranes; Ultra-thin membranes
• CPC Class Codes: B01D 69/1214 Chemically bonded layers, e.g. cross-linking
• CPC Class Codes: B01D 69/1218 Layers having the same chemical composition, but different properties, e.g. pore size, molecular weight or porosity
• CPC Class Codes: B01D 71/022 Metals

Abstract

A method produces a metal-organic framework on a surface of another metal-organic framework. One embodiment comprises contacting the first metal-organic framework with a ligand and solvent solution; wherein the first metal-organic framework comprises a first ligand and a first metal; wherein the ligand and solvent solution comprises a second ligand that is different from the first ligand in the first metal-organic framework; and allowing the second ligand from the ligand and solvent solution to exchange with the first ligand present in the first metal-organic framework for a period of time suitable to produce the second metal-organic framework on the surface of the first metal-organic framework.

Claims

1. A method for producing a second metal-organic framework membrane on the surface of a first metal-organic framework membrane comprising:

forming the first metal-organic framework membrane on a support;

contacting the first metal-organic framework membrane with a metal and solvent solution, wherein the first metal-organic framework membrane comprises a first ligand and a first metal, wherein the metal and solvent solution comprises a second metal that is different from the first metal in the first metal-organic framework membrane; and

allowing the second metal from the metal and solvent solution to exchange with the first metal present in the first metal-organic framework membrane for a period of time suitable to produce the second metal-organic framework membrane on the surface of the first metal-organic framework membrane, wherein the second metal-organic framework membrane comprises a second ligand and a second metal.

2. The method of claim 1, wherein the second metal in the metal and solvent solution comprises iron, copper, zinc, cobalt, aluminum, zirconium, vanadium, chromium, manganese, or any combinations thereof.

3. The method of claim 1, wherein the metal and solvent solution further comprises a catalyst.

4. The method of claim 3, wherein the catalyst comprises an amine, an organic base, an inorganic base, or combinations thereof.

5. The method of claim 1, wherein the solvent comprises water, an alcohol, dimethylformamide, dimethyl sulfoxide, or any combinations thereof.

6. The method of claim 1, wherein a pore size of the second metal-organic framework membrane is different from a pore size of the first metal-organic framework membrane.

7. The method of claim 1, further comprising isolating a gas selected from a mixture of gases, wherein the gas comprises H₂, CO₂, N₂, CH₄, SF₆, C₃H₆, C₃H₈, C₂H₄, C₂H₆, n-C₄H₁₀, i-C₄H₁₀, or combinations thereof;

wherein the isolating the gas is accomplished with the first metal-organic framework membrane and the second-metal organic framework membrane.

8. The method of claim 1, wherein the second ligand comprises an imidazole, a carboxylic acid, or any combinations thereof.

9. The method of claim 1, wherein the second ligand is a different ligand from the first ligand.

10. The method of claim 1, wherein the support comprises a ceramic, a polymer, a stainless steel, or any combinations thereof.

11. A membrane comprising:

a support;

a first metal-organic framework comprising a first ligand and a first metal; and

a second metal-organic framework formed on the first metal-organic framework, wherein the second metal-organic framework comprises a second ligand and a second metal.

12. The membrane of claim 11, wherein the second ligand is different form the first ligand.

13. The membrane of claim 11, wherein the second metal is different from the first metal.

14. The membrane of claim 11, wherein a pore size of the first metal-organic framework is different from a pore size of the second metal-organic framework.

15. The membrane of claim 11, wherein the second ligand comprises an imidazole, a carboxylate, or any combinations thereof.

16. The membrane of claim 11, wherein the second metal comprises iron, copper, zinc, cobalt, aluminum, zirconium, vanadium, chromium, manganese, or any combinations thereof.