Porous substrates, articles, systems and compositions comprising nanofibers and methods of their use and production

• US 20070190880A1
• Filed: 09/15/2004
• Published: 08/16/2007
• Est. Priority Date: 02/02/2004
• Status: Active Grant

• Current Assignee: ONED Material Incorporated
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: Niu, Chunming, Dubrow, Robert
• Granted Patent: US 8,025,960 B2
• Time in Patent Office: Days
• US Class Current: 442/181
• CPC Class Codes: B01D 2239/0225 Side-by-side
• CPC Class Codes: B01D 2239/0233 Island-in-sea
• CPC Class Codes: B01D 2239/0241 comprising electrically conductive fibres or particles
• CPC Class Codes: B01D 2239/025 comprising nanofibres
• CPC Class Codes: B01D 2239/0428 Rendering the filter material hydrophobic
• CPC Class Codes: B01D 2239/0492 on fibres
• CPC Class Codes: B01D 2239/0613 Woven
• CPC Class Codes: B01D 2239/065 More than one layer present in the filtering material
• CPC Class Codes: B01D 2239/1216 Pore size
• CPC Class Codes: B01D 2323/283 Reducing the pores
• CPC Class Codes: B01D 39/08 Filter cloth, i.e. woven, knitted or interlaced material metallic B01D39/10
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/24996 With internal element bridging layers, nonplanar interface between layers, or intermediate layer of commingled adjacent foam layers
• CPC Class Codes: Y10T 442/30 Woven fabric [i.e., woven strand or strip material]

Abstract

Porous nanofiber bearing substrate materials are provided having enhanced surface area for a variety of applications including as electrical substrates, semipermeable membranes and barriers, structural lattices for tissue culturing and for composite materials, and the like.

Claims

1. An article, comprising:

a substrate having a plurality of apertures disposed therethrough, the substrate comprising an overall surface area that includes an interior wall surface area of the plurality of apertures; and

a plurality of nanofibers attached to at least a portion of the overall surface area of the substrate.

2. The article of claim 1, wherein the substrate comprises a solid substrate and wherein the plurality of apertures comprises a plurality of pores disposed through the solid substrate.

3. The article of claim 2, wherein the substrate comprises a silica based wafer.

4. The article of claim 1, wherein the substrate comprises a ceramic sheet or plate.

6. The article of claim 1, wherein the substrate comprises a metallic plate.

7. The article of claim 1, wherein the substrate comprises a mesh.

8. The article of claim 7, wherein the mesh comprises a polymer mesh.

9. The article of claim 8, wherein the polymer mesh comprises a polymer selected from polyimide, polyetherketone, polyaramid.

10. The article of claim 7, wherein the mesh is a metallic mesh.

11. The article of claim 10, wherein the metallic mesh comprises a metal selected from nickel, titanium, platinum, aluminum, gold, and iron.

12. The article of claim 1, wherein the substrate comprises a woven fabric.

13. The article of claim 12, wherein the woven fabric comprises fiberglass.

14. The article of claim 12, wherein the woven fabric comprises carbon fiber.

15. The article of claim 12, wherein the woven fabric comprises a polymer selected from polyimide, polyetherketone, and polyaramid.

16. The article of claim 1, wherein the substrate comprises a fibrous mat.

17. The article of claim 16, wherein the fibrous mat comprises silica based fibers.

18. The article of claim 17, wherein the silica based fibers are selected from glass and silicon.

19. The article of claim 16, wherein the fibrous mat comprises metallic fibers.

20. The article of claim 16, wherein the fibrous mat comprises polymer fibers.

21. The article of claim 1, wherein the plurality of apertures have an effective pore size of less than 10 μ

m.

22. The article of claim 1, wherein the plurality of apertures have an effective pore size of less than 1 μ

m.

25. The article of claim 1, wherein the plurality of nanofibers are substantially only attached to the interior wall surfaces of the apertures.

26. The article of claim 1, wherein the plurality of nanofibers comprises a semiconductor material selected from group IV, group II-VI and group III-V semiconductors.

27. The article of claim 1, wherein the plurality of nanofibers are comprised of silicon.

30. The article of claim 1, wherein the plurality of nanofibers is electrically coupled to the substrate.

31. The article of claim 1, further comprising a matrix material surrounding the substrate and plurality of nanofibers, wherein the matrix material and the plurality of nanofibers have a type-II energy band-gap offset with respect to each other.

33. The article of claim 1, wherein the plurality of nanofibers are functionalized with a chemical binding moiety.

34. The article of claim 1, wherein the plurality of nanofibers are functionalized with a hydrophobic chemical moiety.

37. The article of claim 1, wherein the substrate comprises a non-planar three dimensional shape.

38. The article of claim 37, wherein the three dimensional shape is selected from a cube, a sphere, a cylinder, a block, a dome, and a polyhedron.

39. The article of claim 37, wherein the non-planar three dimensional shape is a cylinder.

40. The article of claim 1, further comprising a matrix material at least partially encapsulating the substrate and plurality of nanofibers attached to at least a portion of the overall surface of the substrate.

41. The article of claim 40, wherein the matrix material is at least partially intercalated into the apertures.

42. The article of claim 41, wherein the matrix material comprises a polymer.

43. The article of claim 42, wherein the polymer comprises a polymer selected from a polyester, an epoxy, a urethane resin, an acrylate resin, polyethylene, polypropylene, nylon, and PFA.

61. An implantable medical device comprising an article of claim 1 attached to and covering at least a portion of a surface of the implantable medical device.

5. (canceled)

23. (canceled)

24. (canceled)

28. (canceled)

29. (canceled)

32. (canceled)

35. (canceled)

36. (canceled)

44. An article, comprising a nanofibrous mat that comprises a plurality of overlaid nanofibers, wherein said plurality of nanofibers are crosslinked together at points where such nanofibers contact or are proximal to others of said nanofibers, to form a semipermeable layer.

45. The article of claim 44, wherein the nanofibrous mat is deposited upon a surface of a porous substrate, the porous substrate and nanofibrous mat forming a semipermeable layer.

46. The article of claim 44, wherein at least a portion of the nanofibers comprise a hydrophobic moiety attached thereto.

47. A semipermeable membrane, comprising:

a porous substrate having a plurality of apertures disposed therethrough, the porous substrate having an overall surface that includes an interior wall surface of the apertures; and

a plurality of nanofibers deposited upon or attached to at least a portion of the overall surface of the porous substrate, wherein the nanofibers and apertures together define a pore through the semipermeable membrane, the pore being permeable to one or more materials and not permeable to one or more different materials.

48-57. -57. (canceled)

62. An electrical device, comprising:

a porous substrate having a plurality of apertures disposed therethrough, the porous substrate having an overall surface area that includes an interior wall surface area of the plurality of apertures; and

a plurality of conductive or semiconductive nanowires attached to and electrically coupled to the porous substrate.

64. A method of producing a contiguous population of nanofibers, comprising:

providing a porous substrate having an overall surface area;

providing a plurality of nanofibers attached to the overall surface area of the porous substrate.

65. A method of producing a contiguous population of nanofibers, comprising:

providing a porous substrate having an upper surface an a plurality of pores disposed through the porous substrate, wherein each of said pores has an effective pore size;

depositing a plurality of nanofibers onto the upper surface of the porous substrate, said nanofibers having at least one dimension greater than the effective pore size, such that the nanofibers are retained upon the upper surface as a nanofibrous mat; and

crosslinking individual nanofibers in the plurality of nanofibers with other individual nanofibers of the plurality of nanofibers to produce a contiguous nanofiber population.

66. A method of filtering a fluid or gas, comprising:

providing a substrate having a plurality of apertures disposed therethrough to provide a porous substrate that has an overall surface area that includes an interior wall surface area of the apertures, the substrate comprising a plurality of nanowires attached to at least a portion of the overall surface area of the porous substrate; and

passing the gas or liquid through the porous substrate to filter the gas or liquid.

67. A method of producing a gas permeable moisture barrier, comprising:

providing a porous substrate that comprises a plurality of apertures therethrough;

providing a plurality of nanofibers attached to at least a portion of an overall surface area of the porous substrate, the porous substrate and nanofibers together providing a gas permeable barrier; and

treating at least the nanofibers to increase hydrophobicity of the nanofibers attached to the overall surface of the porous substrate, to provide a gas permeable moisture barrier.