Thermally stable aerogels and aerogel composites

Patent metadata

Field	Value
Publication number	US-2025236564-A1
Application number	US-202519034161-A
Country	US
Kind code	A1
Filing date	Jan 22, 2025
Priority date	Jan 24, 2024
Publication date	Jul 24, 2025
Grant date	—

Abstract

A metal oxide-coated aerogel has an aerogel structure comprising yttria-stabilized zirconia (YSZ) and a coating on the aerogel structure. The YSZ includes at least about 20 mol. % yttria (YO1.5) in zirconia (ZrO2) and the coating comprises a metal oxide selected from the group consisting of silica, alumina, zirconia, and titania. An aerogel composite includes a fibrous material and an aerogel on surfaces and within interstices of the fibrous material, where the aerogel has an aerogel structure comprising yttria-stabilized zirconia (YSZ) and a coating on the aerogel structure that comprises a metal oxide. A method of forming a thermally stable aerogel comprises: forming a gel comprising yttria-stabilized zirconia (YSZ) including at least about 20 mol. % yttria (YO1.5) in zirconia (ZrO2); immersing the gel in a coating solution comprising a metal alkoxide and ethanol; and after the immersion, supercritically drying the gel, thereby forming a metal oxide-coated aerogel.

First claim

1 . A thermally stable aerogel comprising:
an aerogel structure comprising yttria-stabilized zirconia (YSZ) including at least about 20 mol. % yttria (YO 1.5 ) in zirconia (ZrO 2 ); a coating on the aerogel structure, the coating comprising a metal oxide selected from the group consisting of silica, alumina, zirconia, and titania.

2 . The thermally stable aerogel of claim 1 , wherein the YSZ includes from 30 mol. % yttria (YO 1.5 ) to 50 mol. % yttria (YO 1.5 ) in the zirconia.

3 . The thermally stable aerogel of claim 1 having a specific surface area (SSA) of at least 350 m 2 /g at 600° C.

4 . The thermally stable aerogel of claim 1 having a cumulative pore volume of at least about 1.8 cm 3 /g at 600° C.

5 . The thermally stable aerogel of claim 1 , wherein the YSZ remains amorphous up to 1000° C. as determined by x-ray diffraction.

6 . The thermally stable aerogel of claim 1 , wherein the coating has a thickness less than an average size of pores of the aerogel structure.

7 . The thermally stable aerogel of claim 1 , wherein the aerogel structure includes pores from 20 nm to 50 nm in average size.

8 . The thermally stable aerogel of claim 1 , wherein the coating has a thickness in a range from 1 nm to 10 nm.

9 . An insulation product including the thermally stable aerogel of claim 1 .

10 . An aerogel composite comprising:
a fibrous material; an aerogel on surfaces and within interstices of the fibrous material, the aerogel including an aerogel structure comprising yttria-stabilized zirconia (YSZ); and a coating on the aerogel structure, the coating comprising a metal oxide.

11 . The aerogel composite of claim 10 , wherein the fibrous material comprises a woven fibrous material.

12 . The aerogel composite of claim 10 , wherein the fibrous material comprises a non-woven fibrous material.

13 . The aerogel composite of claim 10 , wherein the fibrous material comprises natural or synthetic fibers selected from the group consisting of alumina fibers, aluminosilicate fibers, and aluminoborosilicate fibers.

14 . The aerogel composite of claim 10 , wherein the metal oxide is selected from the group consisting of silica, alumina, zirconia, and titania.

15 . The aerogel composite of claim 10 , wherein the YSZ includes from 20 mol. % yttria (YO 1.5 ) to 50 mol. % yttria (YO 1.5 ) in zirconia (ZrO 2 ).

16 . The aerogel composite of claim 10 having a configuration of a flexible sheet.

17 . An insulation product comprising the aerogel composite of claim 10 .

18 . A method of forming a thermally stable aerogel, the method comprising:
forming a gel comprising yttria-stabilized zirconia (YSZ) including at least about 20 mol. % yttria (YO 1.5 ) in zirconia (ZrO 2 ); immersing the gel in a coating solution comprising a metal alkoxide and ethanol; and after the immersion, supercritically drying the gel, thereby forming a metal oxide-coated aerogel.

19 . The method of claim 18 , wherein the coating solution includes the metal alkoxide at a concentration in a range from 20 vol. % to 30 vol. %.

20 . The method of claim 18 , wherein the metal alkoxide is selected from the group consisting of tetraethyl orthosilicate, aluminum-tri-sec-butoxide, zirconium(IV) butoxide, and titanium(IV) isopropoxide.

Assignees

• Univ Illinois
• Nasa

Inventors

• Olson Nathaniel S
• Krogstad Jessica A
• Hurwitz Frances I
• Guo Haiquan
• Stokes Jamesa L

Classifications

• C04B2111/00982

  as construction elements for space vehicles or aeroplanes · CPC title

• C04B41/463

  Organic solvents · CPC title

• C04B41/4539

  as a emulsion, dispersion or suspension · CPC title

• C04B41/87

  Ceramics · CPC title

• C04B41/009

  characterised by the material treated · CPC title