Methods to enhance separation performance of metal-organic framework membranes

• US 9,789,444 B2
• Filed: 03/03/2015
• Issued: 10/17/2017
• 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
• Primary Examiner(s): Shumate, Anthony
• Application Number:
  US14/637,088
• Publication Number:
  US 20150251139A1
• Time in Patent Office: 959 Days
• 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 on a surface of a first metal-organic framework comprising:

(A) 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

(B) 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.

2. The method of claim 1, wherein the second ligand in the ligand and solvent solution comprises an imidazole, a carboxylic acid, or any combinations thereof.

3. The method of claim 1, wherein the ligand and solvent solution further comprises a catalyst, wherein the catalyst comprises an amine, an organic base, an inorganic base, or any combinations thereof.

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

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

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

wherein the isolating the gas is accomplished by a selectively permeable membrane formed from the first metal-organic framework and the second metal-organic framework.

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