Titanium Dioxide Coatings and Methods of Forming Titanium Dioxide Coatings Having Reduced Crystallite Size

• US 20100062265A1
• Filed: 09/09/2008
• Published: 03/11/2010
• Est. Priority Date: 09/09/2008
• Status: Abandoned Application

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: SHARMA, PRAMOD K.
• Application Number:
  US12/207,235
• Publication Number:
  US 20100062265A1
• Time in Patent Office: Days
• US Class Current: 428/432
• CPC Class Codes: A01N 25/04 Dispersions, emulsions, suspoemulsions, suspension concentrates or gels foams A01N25/16
• CPC Class Codes: A01N 25/34 Shaped forms, e.g. sheets, not provided for in any other sub-group of this main group
• CPC Class Codes: A01N 59/16 Heavy metals; Compounds thereof
• 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: B01J 37/0215 Coating
• CPC Class Codes: B01J 37/08 Heat treatment B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: C01G 23/053 Producing by wet processes, e.g. hydrolysing titanium salts
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C03C 17/256 Coating containing TiO2
• CPC Class Codes: C03C 2217/212 TiO2
• CPC Class Codes: C03C 2218/113 by sol-gel processes
• CPC Class Codes: C09C 1/3607 Titanium dioxide

Abstract

Methods for forming titanium dioxide coatings having crystals comprising reduced crystallite size are disclosed. Sol-gel compositions are prepared, formed on a substrate, and the coated substrate is heated at a temperature sufficient to form a titanium dioxide coating with crystals having a reduced crystallite size. Titanium dioxide coatings having crystals comprising reduced crystallite size and having at least one of improved antimicrobial properties, self-cleaning properties, and/or hydrophilicity are also disclosed. Substrates comprising such coatings are also disclosed.

Claims

1. A method of forming a titanium dioxide coating comprising crystals having a reduced crystallite size on a substrate, comprising:

preparing a titanium dioxide sol-gel composition;

coating the substrate with the sol-gel composition; and

heating the coated substrate at a temperature sufficient to form a titanium dioxide coating comprising crystals having a reduced crystallite size.

2. The method of claim 1, wherein said coated substrate is heated at a temperature of at least 575°

C.

3. The method of claim 2, wherein said coated substrate is heated at a temperature of at least about 600°

C.

4. The method of claim 1, wherein the coated substrate is heated at a temperature sufficient to form a titanium dioxide coating comprising a water contact angle less than about 10°

.

5. The method of claim 1, wherein the titanium dioxide coating comprises crystals having a crystallite size less than about 35 nm.

6. The method of claim 5, wherein the titanium dioxide coating comprises crystals having a crystallite size less than about 25 nm.

7. The method of claim 1, wherein the substrate comprises a glass substrate.

8. The method of claim 7, wherein the glass substrate is chosen from clear and low-iron glass.

9. A method of improving at least one of antimicrobial properties, self-cleaning properties, and hydrophilicity of a titanium dioxide coating, comprising:

preparing a titanium dioxide sol-gel composition;

coating a substrate with the sol-gel composition; and

heating the coated substrate to form a titanium dioxide coating comprising crystals having a reduced crystallite size.

10. The method of claim 9, wherein the coated substrate is heated at a temperature at least about 575°

C.

11. The method of claim 10, wherein the coated substrate is heated at a temperature at least about 600°

C.

12. The method of claim 9, wherein said crystals have a crystallite size less than about 35 nm.

13. The method of claim 12, wherein said crystals have a crystallite size less than about 25 nm.

14. The method of claim 9, wherein the titanium dioxide coating comprises a water contact angle less than about 10°

.

15. A substrate comprising a titanium dioxide coating comprising crystals having a reduced crystallite size, wherein the titanium dioxide coating comprises crystals having a crystallite size less than about 35 nm.

16. The substrate comprising a titanium dioxide coating comprising crystals having a reduced crystallite size of claim 15, wherein the titanium dioxide coating comprises crystals having a crystallite size less than about 25 nm.

17. The substrate comprising a titanium dioxide coating comprising crystals having a reduced crystallite size of claim 15, wherein the titanium dioxide coating comprises a water contact angle less than about 10°

.

18. The substrate comprising a titanium dioxide coating comprising crystals having a reduced crystallite size of claim 15, wherein the substrate comprises a glass substrate.

19. The antimicrobial coating of claim 18, wherein the glass substrate is chosen from clear and low iron glass.

20. A titanium dioxide coating having at least one of improved antimicrobial properties, improved self-cleaning properties, and improved hydrophilicity, wherein said titanium dioxide coating is made by:

preparing a titanium dioxide sol-gel composition;

coating a substrate with the sol-gel composition; and

heating the coated substrate to form a titanium dioxide coating comprising crystals having a reduced crystallite size.

21. A substrate comprising a titanium dioxide coating having a reduced crystallite size, wherein said titanium dioxide coating is made by:

preparing a titanium dioxide sol-gel composition;

coating the substrate with the sol-gel composition; and

heating the coated substrate at a temperature sufficient to form a titanium dioxide coating comprising crystals having a reduced crystallite size.