Method of forming a hydrophilic membrane

Patent metadata

Field	Value
Publication number	US-9393529-B2
Application number	US-99291609-A
Country	US
Kind code	B2
Filing date	May 19, 2009
Priority date	Jun 30, 2008
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

The present disclosure provides methods for forming hydrophilic membranes. More specifically, methods are provided for hydrophilic membranes from a solution comprising an ethylene-vinyl alcohol copolymer, water, and a first solvent. At least a portion of the first solvent is removed from the porous substrate at a temperature no greater than 500 C. for forming a hydrophilic membrane.

First claim

What is claimed is:

1. A method of forming a hydrophilic membrane comprising:
providing a hydrophobic porous substrate, wherein the porous substrate comprises polypropylene;
applying a solution to the hydrophobic porous substrate, the solution consisting essentially of
i) an ethylene-vinyl alcohol copolymer;
ii) water; and
iii) a first solvent, the first solvent miscible with water and having a boiling point less than the boiling point of water, wherein the first solvent comprises alcohols selected from methanol, ethanol, isopropanol n-propanol, or combinations thereof; and

removing at least a portion of the first solvent from the porous substrate at a temperature no greater than 40° C. to provide the hydrophilic membrane, wherein the hydrophilic membrane has a surface energy greater than 60 dynes/centimeter.

2. The method of claim 1 , wherein the porous substrate comprises a microporous, thermally-induced phase separation membrane.

3. The method of claim 1 , wherein the porous substrate comprises a film, a nonwoven web, a woven web, a hollow fiber or combinations thereof.

4. The method of claim 1 , wherein the porous substrate further comprises polyolefins, polyamides, fluorinated polymers, poly(ether)sulfones, cellulosics, poly(ether)imides, polyacrylonitriles, polyvinylchlorides, ceramics, or combinations thereof.

5. The method of claim 1 , wherein the porous substrate further comprises polyolefins.

6. The method of claim 5 , wherein the polyolefins comprise polyethylene.

7. The method of claim 5 , wherein the porous substrate comprises polyamides.

8. The method of claim 7 , wherein the polyamides comprise nylon 6,6.

9. The method of claim 1 , wherein the applying comprises die coating, roll coating, dip coating, spray coating, curtain coating, slide coating or combinations thereof.

10. The method of claim 1 , wherein the ethylene-vinyl alcohol copolymer has a concentration of 1 to 20 weight percent in the solution.

11. The method of claim 1 , wherein the ethylene-vinyl alcohol copolymer has a concentration of 2 to 10 weight percent in the solution.

12. The method of claim 1 , wherein the ethylene-vinyl alcohol copolymer comprises an ethylene content in a range from 10 to 50 mole percent.

13. The method of claim 1 , wherein the volume percent of water of the solution is in a range of 5 to 80 volume percent based on the total volume of the first solvent and water.

14. The method of claim 1 , wherein the volume percent of the first solvent of the solution is in a range of 20 to 95 volume percent based on the total volume of the first solvent and water.

15. The method of claim 1 , wherein the removing comprises convection, reduced pressure, heating, or combinations thereof.

16. The method of claim 1 , wherein the hydrophilic membrane has a surface energy greater than 65 dynes/centimeter.

17. A hydrophilic membrane formed by the method of claim 1 .

18. The method of claim 1 , wherein the temperature is no greater than 30° C.

Assignees

• Zhou Jinsheng
• 3M Innovative Properties Co

Inventors

• Zhou Jinsheng

Classifications

• B01D71/26

  Polyalkenes · CPC title

• B01D2325/36

  Hydrophilic membranes · CPC title

• B01D67/0011 Primary

  Casting solutions therefor · CPC title

• B01D69/10

  Supported membranes; Membrane supports · CPC title

• B01D71/76

  Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74 (rubbers in general B01D71/24) · CPC title