Nanotube Assisted Self-Cleaning Material

• US 20100291375A1
• Filed: 05/14/2009
• Published: 11/18/2010
• Est. Priority Date: 05/14/2009
• Status: Active Grant

• Current Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Original Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Inventors: Eldering, Charles A., Ehrlacher, Edward A.
• Granted Patent: US 8,273,425 B2
• Time in Patent Office: Days
• US Class Current: 428/332
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 35/004 Photocatalysts
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: Y10T 428/131 Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.]
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

A self-cleaning material is generally described that may include a substrate having a first surface. A self-cleaning layer of aligned nanotube structures may be formed on the first surface of the substrate, where absorption of light by the nanotube structures may cause a change in state of the self-cleaning material based on an angle of incidence of the light and an orientation vector corresponding to the layer of aligned nanotube structures.

Claims

1. A self-cleaning material that is responsive to exposure to light comprising:

a substrate having a first surface; and

a self-cleaning layer of aligned nanotube structures formed on the first surface of the substrate, wherein the nanotube structures are aligned according to an orientation vector such that the self-cleaning material changes states responsive to the exposure to light based at least in part on an angle of incidence of the light with respect to the first surface of the substrate.

2. The method of claim 1, wherein the nanotube structures of the self-cleaning layer are arranged in a substantially parallel alignment to each other.

3. The self-cleaning material of claim 1, wherein the self-cleaning layer is further arranged such that absorption of light by the self-cleaning layer of aligned nanotube structures increases as the angle of incidence of the light approaches becoming parallel with the orientation vector.

4. The self-cleaning material of claim 1, wherein the orientation vector is substantially perpendicular to the first surface of the substrate.

5. The self-cleaning material of claim 1, wherein the orientation vector is nearly parallel to the first surface of the substrate.

6. The self-cleaning material of claim 1, wherein the self-cleaning layer of aligned nanotube structures is either photocatalytic, hydrophobic, and/or hydrophilic in response to exposure to the light.

7. The self-cleaning material of claim 6, wherein the light is ultraviolet light.

8. The self-cleaning material of claim 1, wherein the nanotube structures at least partially comprise titanium dioxide nanotube structures.

9. The self-cleaning material of claim 1, wherein the nanotube structures are a different material than the substrate.

10. A self-cleaning material that is responsive to exposure to light comprising:

a substrate having a first surface and a second surface;

a first self-cleaning layer of aligned nanotube structures formed on the first surface of the substrate, wherein the nanotube structures of the first self-cleaning layer are aligned according to a first orientation vector and arranged such that the first self-cleaning layer changes states responsive to the exposure to light based at least in part on the first orientation vector; and

a second self-cleaning layer of aligned nanotube structures formed on the second surface of the substrate, wherein the nanotube structures of the second self-cleaning layer are aligned according to a second orientation vector and arranged such that the second self-cleaning layer changes states responsive to the exposure to light based at least in part on the second orientation vector.

11. The method of claim 10, wherein the nanotube structures of the first self-cleaning layer and the nanotube structures of the second self-cleaning layers are different materials.

12. The method of claim 10, wherein the first and second self-cleaning layers are further arranged such that absorption of light by the first and second self-cleaning layers causes the first and second self-cleaning layers, respectively, to become either photocatalitic, hydrophobic, and/or hydrophilic.

13. The method of claim 12, wherein the second self-cleaning layer exhibits a different self-cleaning property than the first self-cleaning layer.

14. The method of claim 10, wherein the first and second orientation vectors correspond to most probable angles of incidence of the light on the first and second self-cleaning layers, respectively.

15. The method of claim 10, wherein the first orientation vector is selected based on the first self-cleaning layer being utilized in an uncontrolled environment and the second orientation vector is selected based on the second self-cleaning layer being utilized in a controlled environment.

16. A self-cleaning material that is responsive to exposure to light comprising:

a self-cleaning layer of aligned titanium dioxide nanotube structures formed on a first surface of a glass substrate, wherein the titanium dioxide nanotube structures of the self cleaning layer are aligned according to an orientation vector such that absorption of light by the titanium dioxide nanotube structures of the self cleaning layer induces a photo-induced hydrophilic state of the self-cleaning layer of aligned titanium dioxide nanotubes based at least in part on a first incident angle of the light with respect to the first surface of the glass substrate.

17. The self-cleaning material of claim 16, wherein the self-cleaning layer is further arranged such that absorption of light by the self-cleaning layer of aligned titanium dioxide nanotube structures is increased as the angle of incidence of the light approaches becoming parallel with the orientation vector.

18. The self-cleaning material of claim 16, wherein the self-cleaning layer is further arranged such that absorption of light by the titanium dioxide nanotube structures of the self-cleaning layer further induces a photo-catalytic state of the self-cleaning layer based on the orientation vector corresponding to the self-cleaning layer and the incident angle of the light with the first surface of the glass substrate.

19. The self-cleaning material of claim 18, wherein the light is ultraviolet light.

20. The self-cleaning material of claim 16, further comprising:

a second self-cleaning layer of aligned titanium dioxide nanotube structures formed on a second surface of the glass substrate wherein the titanium dioxide nanotube structures of the second self cleaning layer are aligned according to a second orientation vector such that absorption of light by the titanium dioxide nanotube structures of the second self cleaning layer induces a photo-induced hydrophilic state of the second self-cleaning layer based at least in part on a second angle of incidence of the light with respect to the second surface of the glass substrate.