Fire-retardant nanocellulose aerogels, and methods of preparation and uses thereof

Patent metadata

Field	Value
Publication number	US-10919262-B2
Application number	US-201815869879-A
Country	US
Kind code	B2
Filing date	Jan 12, 2018
Priority date	Jan 12, 2017
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Disclosed are multilayered aerogel nanocomposite materials, and methods of making and using them.

First claim

We claim:

1. An aerogel comprising a plurality of layers, wherein the plurality of layers includes at least one inner layer and an outer layer; each inner layer forms a core that structurally supports the outer layer; at least one inner layer comprises cellulose nanofibers; the outer layer comprises metallic molybdenum disulfide (MoS 2 ); and all of the layers are bonded together to form a single, substantially fire resistant structure.

2. The aerogel of claim 1 , having a density from about 0.003 g/cm 3 to 0.006 g/cm 3 .

3. The aerogel of claim 1 , having a porosity from about 95% to about 99%.

4. The aerogel of claim 1 , having a thermal conductivity from about 26 mW/m·K to about 29 mW/m·K.

5. The aerogel of claim 1 , wherein the cellulose nanofibers are oxidized cellulose nanofibers.

6. The aerogel of claim 5 , wherein the cellulose nanofibers form a two dimensional nanostructure.

7. The aerogel of claim 6 , wherein the two dimensional nanostructure is a nanosheet.

8. The aerogel of claim 1 , wherein the cellulose nanofibers are softwood cellulose nanofibers.

9. The aerogel of claim 1 , wherein the metallic MoS 2 and the cellulose nanofibers are crosslinked to form metal-carboxylate complexes.

10. A method of preparing the aerogel of claim 1 , comprising freeze-drying a mixture of cellulose nanofibers and MoS 2 .

11. The method of claim 10 , wherein the cellulose nanofibers are oxidized cellulose nanofibers.

12. The method of claim 11 , wherein the oxidized cellulose nanofibers are prepared by oxoammonium-catalyzed oxidation of softwood pulp.

13. The method of claim 12 , wherein the oxoammonium-catalyzed oxidation comprises reacting softwood pulp and an oxidizing agent.

14. The method of claim 13 , wherein the oxidizing agent is sodium hypochlorite, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) or a derivative thereof, potassium permanganate, chromium trioxide, pyridinium chlorochromate in dimethylformamide, ruthenium tetroxide, or platinium in an oxygen atmosphere.

15. The method of claim 10 , further comprising immersing the mixture of cellulose nanofibers and MoS 2 in a cryogenic fluid prior to freeze-drying the mixture.

16. The method of claim 10 , further comprising crosslinking the metallic MoS 2 and the cellulose nanofibers.

17. The method of claim 10 , further comprising suspending the mixture of cellulose nanofibers and metallic MoS 2 in deionized water prior to immersing the mixture in the cryogenic fluid.

18. A method of fire protection, comprising providing a fire zone with the aerogel of claim 1 .

19. The method of claim 18 , wherein the fire zone is in a vehicle or a construction zone.

Assignees

• Univ Northeastern

Inventors

• Zhu Hongli
• Yang Lei

Classifications

• Y02T70/10

  Measures concerning design or construction of watercraft hulls · CPC title

• E04B1/941

  Building elements specially adapted therefor · CPC title

• E04B1/76

  specifically with respect to heat only (heat insulation in general F16L59/00) · CPC title

• C09K21/02

  Inorganic materials · CPC title

• B01J13/0091 Primary

  Preparation of aerogels, e.g. xerogels · CPC title