Method of preparing hydrophobic metal oxide-silica composite aerogel and hydrophobic metal oxide-silica composite aerogel prepared thereby

Patent metadata

Field	Value
Publication number	US-10399857-B2
Application number	US-201615537188-A
Country	US
Kind code	B2
Filing date	Oct 18, 2016
Priority date	Nov 3, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

The present invention relates to a method of preparing a hydrophobic metal oxide-silica composite aerogel having a high specific surface area and a low tap density and a hydrophobic metal oxide-silica composite aerogel prepared thereby. Thus, the preparation method may not only have excellent productivity and economic efficiency due to a relatively simpler preparation process and shorter preparation time than the related art, but may also prepare a hydrophobic metal oxide-silica composite aerogel having a high specific surface area and a low tap density.

First claim

The invention claimed is:

1. A method of preparing a hydrophobic, co-precipitated metal oxide-silica aerogel, the method comprising steps of:
(1) adding a metal ion solution and an acid catalyst to a water glass solution and mixing together to prepare a metal oxide-silica gel;
(2) surface-modifying the co-precipitated metal oxide-silica gel to prepare a hydrophobic, co-precipitated metal oxide-silica wet gel; and
(3) drying the hydrophobic co-precipitated metal oxide-silica wet gel,
wherein the method further comprises treating the co-precipitated metal oxide-silica gel with alcohol before the surface modification of step 2, and
wherein the metal ion solution is a binary metal ion solution including calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ).

2. The method of claim 1 , wherein a concentration of water glass in the water glass solution is in a range of 0.1 M to 2.0 M.

3. The method of claim 1 , wherein a concentration of metal ions in the metal ion solution is in a range of 0.05 M to 2.0 M.

4. The method of claim 1 , wherein the drying of step (3) is performed by atmospheric pressure drying at a temperature of 105° C. to 190° C. for 1 hour to 4 hours.

5. The method of claim 1 , wherein a molar ratio of the calcium ion (Ca 2+ ) to the magnesium ion (Mg 2+ ) in the metal ion solution is in a range of 1:0.3 to 1:3.

6. The method of claim 1 , wherein the metal ion solution is added in an amount such that a molar ratio of metal ions to water glass is in a range of 0.5 to 1.

7. The method of claim 1 , wherein step 1 is performed at a pH of 6 to 8.

8. The method of claim 1 , wherein the acid catalyst comprises at least one selected from the group consisting of hydrochloric acid, nitric acid, acetic acid, sulfuric acid, and hydrofluoric acid.

9. The method of claim 1 , wherein the alcohol comprises at least one selected from the group consisting of methanol and ethanol.

10. The method of claim 1 , wherein the surface modification of step 2 is performed by adding a surface modifier to the co-precipitated metal oxide-silica gel and performing a reaction.

11. The method of claim 10 , wherein the surface modifier comprises at least one selected from the group consisting of trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDS), methyltrimethoxysilane, and trimethylethoxysilane.

12. The method of claim 10 , wherein the surface modifier is added in a molar ratio of 1.0 to 4.0 with respect to water glass.

13. The method of claim 1 , wherein the surface modification of step 2 is performed by dispersing the co-precipitated metal oxide-silica gel in a non-polar organic solvent, adding a surface modifier, and performing a reaction.

14. The method of claim 13 , wherein the non-polar organic solvent comprises at least one selected from the group consisting of hexane, heptane, toluene, and xylene.

15. The method of claim 1 , wherein the surface modification is performed at a temperature of 55° C. to 65° C.

Assignees

• Lg Chemical Ltd

Inventors

• Jeon Hyun Woo
• Kim Jong Hun
• Lee Je Kyun

Classifications

• C01P2006/90

  Other properties not specified above · CPC title

• C01B33/1585 Primary

  Dehydration into aerogels · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2006/11

  Powder tap density · CPC title

• C08K3/36

  Silica · CPC title