Filter Membrane

• US 20080302243A1
• Filed: 06/06/2007
• Published: 12/11/2008
• Est. Priority Date: 06/06/2007
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Byrd, Norman R., Huang, James P., Gross, Gwen
• Granted Patent: US 7,854,788 B2
• Time in Patent Office: Days
• US Class Current: 95/278
• CPC Class Codes: B01D 2323/42 Details of membrane preparation apparatus
• CPC Class Codes: B01D 2325/02 Details relating to pores or porosity of the membranes
• CPC Class Codes: B01D 2325/02832 1-10 nm
• CPC Class Codes: B01D 2325/48 Antimicrobial properties
• CPC Class Codes: B01D 46/543 using membranes
• CPC Class Codes: B01D 67/0023 by inducing porosity into non porous precursor membranes
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/10 Supported membranes; Membrane supports
• CPC Class Codes: B01D 69/105 Support pretreatment
• CPC Class Codes: B01D 69/1071 Woven, non-woven or net mesh
• CPC Class Codes: Y10S 55/05 Methods of making filter
• CPC Class Codes: Y10S 95/903 Carbon
• CPC Class Codes: Y10S 977/90 having step or means utilizing mechanical or thermal property, e.g. pressure, heat
• CPC Class Codes: Y10S 977/903 for conversion, containment, or destruction of hazardous material

Abstract

A filter membrane includes a substrate, a polymer layer provided on the substrate and a plurality of filter openings each having a width of from about 2 nanometers to about 5 nanometers provided in the polymer layer. A method of controlling pore size of a filter membrane and a method of decontaminating a filter membrane are also disclosed.

Claims

1. A filter membrane, comprising:

a substrate;

a polymer layer provided on said substrate; and

a plurality of filter openings each having a width of from about 2 nanometers to about 5 nanometers provided in said polymer layer.

2. The filter membrane of claim 1 wherein said substrate comprises a plurality of carbon fibers.

4. The filter membrane of claim 1 wherein said polymer layer is organic.

5. The filter membrane of claim 4 wherein said polymer layer comprises carboxymethyl cellulose, polyamic acid (polyimide precursor), polyphenol, polystyrene sulfonic acid, polyacrylic acid, polymethacrylic acid, polythiophenol, carboxyl-terminated acrylonitrile/butadiene copolymer, or polyacrylic acid/butadiene copolymer.

6. The filter membrane of claim 1 further comprising silver provided in said polymer layer.

7. The filter membrane of claim 1 wherein said polymer layer is inorganic.

3. The filter membrane of claim 3 wherein each of said plurality of carbon fibers has a diameter of about 1 μ

m to about 50 μ

m.

8. A method of controlling pore size of a filter membrane, comprising:

providing a substrate;

applying a polymer layer to said substrate; and

forming filter openings in said polymer layer by heating said polymer layer under inert atmosphere and evolving volatile materials from said polymer layer.

9. The method of claim 8 wherein said applying a polymer layer to said substrate comprises electrodepositing said polymer layer on said substrate.

10. The method of claim 9 further comprising activating said substrate by heating said substrate prior to said electrodepositing said polymer layer on said substrate.

11. The method of claim 9 further comprising curing said polymer layer by heating said polymer layer after said electrodepositing said polymer layer on said substrate.

12. The method of claim 8 further comprising providing silver in said polymer layer.

13. The method of claim 8 wherein said substrate comprises a plurality of carbon fibers.

14. The method of claim 13 wherein each of said plurality of carbon fibers has a diameter of about 1 μ

m to about 50 μ

m.

15. The method of claim 13 wherein said plurality of carbon fibers are cotton fibers, polyester fibers or polypropylene fibers.

16. The method of claim 8 wherein said polymer layer comprises carboxymethyl cellulose, polyamic acid (polyimide precursor), polyphenol, polystyrene sulfonic acid, polyacrylic acid, polymethacrylic acid, polythiophenol, carboxyl-terminated acrylonitrile/butadiene copolymer, or polyacrylic acid/butadiene copolymer.

17. A method of decontaminating a filter membrane having nanoscale pores, comprising:

inducing an electrical current greater than 3 volts across said filter membrane.

18. The method of claim 17 wherein said filter membrane comprises a substrate, a polymer layer provided on said substrate and a plurality of filter openings each having a width of from about 2 nanometers to about 5 nanometers provided in said polymer layer.