Vanadium oxide for infrared coatings and methods thereof

Patent metadata

Field	Value
Publication number	US-10160660-B1
Application number	US-201514723334-A
Country	US
Kind code	B1
Filing date	May 27, 2015
Priority date	May 28, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

The present invention relates to vanadium oxide and methods of controlling reaction processes for making such materials (e.g., powders). In particular embodiments, the method includes control of oxygen partial pressure in order to kinetically control the oxidation species of the crystalline vanadium oxide material. Other methods, uses, systems, protocols, and coatings are also described.

First claim

The invention claimed is:

1. A method of preparing crystalline vanadium oxide, the method comprising:
(i) providing a vanadium oxide precursor comprising vanadium oxide particles; and
(ii) annealing the vanadium oxide particles at a first O 2 partial pressure of from about 2 ppm to about 500 ppm, thereby preparing the crystalline vanadium oxide in tetragonal form.

2. The method of claim 1 , wherein step (ii) is performed at a first temperature of from about 200° C. to about 500° C.

3. The method of claim 2 , wherein step (ii) is performed for about 5 minutes or more.

4. The method of claim 2 , wherein step (ii) is performed by using a rapid annealing rate from an initial temperature to the first temperature, wherein the annealing rate is of from about 1° C. per minute to about 200° C. per minute.

5. The method of claim 1 , further comprising:
(iii) obtaining one or more spectroscopy measurements of one or more vanadium oxide form(s) prepared in step (ii); and
(iv) optionally adjusting to a second O 2 partial pressure, wherein the second O 2 partial pressure is less than the first O 2 partial pressure, thereby further isolating the crystalline vanadium oxide in tetragonal form.

6. The method of claim 5 , further comprising (iv) adjusting to a second O 2 partial pressure, wherein the second O 2 partial pressure is less than the first O 2 partial pressure, thereby further isolating the crystalline vanadium oxide in tetragonal form.

7. The method of claim 1 , wherein the crystalline vanadium oxide is VO 2 .

8. The method of claim 1 , wherein the vanadium oxide particles comprises nanoparticles and/or microparticles.

9. The method of claim 1 , wherein the crystalline vanadium oxide has substantially the same morphology as the vanadium oxide particles.

10. The method of claim 9 , wherein the vanadium oxide particles comprise vanadium pentoxide V 2 O 5 .

11. The method of claim 2 , wherein step (ii) is performed at a first temperature of from about 300° C. to about 450° C.

12. The method of claim 11 , wherein step (ii) is performed for about 5 minutes to about 6 hours.

13. The method of claim 1 , wherein the vanadium oxide particles comprises spherical particles.

14. The method of claim 1 , wherein the vanadium oxide particles comprises a dopant.

15. The method of claim 14 , wherein the dopant comprises tungsten.

16. The method of claim 1 , wherein the crystalline vanadium oxide comprises a 20 peak at about 27.6°, 27.8°, 37.0°, and/or 37.2°.

17. The method of claim 1 , wherein step (ii) is performed at the first O 2 partial pressure of about 50 ppm.

18. The method of claim 1 , wherein step (ii) is performed with O 2 and in the presence of a second gas selected from the group consisting of N 2 , He, and Ar.

19. A method of preparing crystalline vanadium oxide, the method comprising:
providing a vanadium oxide precursor comprising vanadium oxide particles;
(ii) annealing the vanadium oxide particles at a first O 2 partial pressure of from about 2 ppm to about 500 ppm, thereby preparing the crystalline vanadium oxide in tetragonal form; and
(iii) obtaining one or more spectroscopy measurements of one or more vanadium oxide form(s) prepared in step (ii).

20. The method of claim 19 , wherein the crystalline vanadium oxide has substantially the same morphology as the vanadium oxide particles.

21. A method of preparing crystalline vanadium oxide, the method comprising:
(i) providing a vanadium oxide precursor comprising vanadium oxide nanoparticles; and
(ii) annealing the vanadium oxide nanoparticles at a first O 2 partial pressure of from about 2 ppm to about 500 ppm, thereby preparing the crystalline vanadium oxide in tetragonal form.

22. The method of claim 21 , wherein the vanadium oxide nanoparticles comprises spherical particles.

23. The method of claim 21 , wherein the vanadium oxide nanoparticles comprises a dopant.

Assignees

• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Rodriguez Mark A
• Bell Nelson S
• Clem Paul G
• Edney Cynthia
• Griego James

Classifications

• B01J6/00

  Heat treatments such as} Calcining; Fusing {; Pyrolysis (furnaces F27D) · CPC title

• B01J2219/00164

  controlling the flow · CPC title

• C01G31/02 Primary

  Oxides · CPC title

• B01J19/0006

  Controlling or regulating processes (controlling or regulating in general G05) · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title