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-2018002182-A1
Application number	US-201615537188-A
Country	US
Kind code	A1
Filing date	Oct 18, 2016
Priority date	Nov 3, 2015
Publication date	Jan 4, 2018
Grant date	—

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

1 . A method of preparing a hydrophobic metal oxide-silica composite 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 composite gel; (2) surface-modifying the metal oxide-silica composite gel to prepare a hydrophobic metal oxide-silica composite wet gel; and (3) drying the hydrophobic metal oxide-silica composite wet gel, wherein the method further comprises treating the metal oxide-silica composite gel with alcohol before the surface modification of step 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 metal ion solution is a binary metal ion solution including calcium ions (Ca 2+ ) and magnesium ions (Mg 2+ ).

5 . The method of claim 4 , 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 metal oxide-silica composite gel and performing a reaction.

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

12 . The method of claim 11 , wherein the non-polar organic solvent comprises at least one selected from the group consisting of hexane, heptane, toluene, and xylene.

13 . 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.

14 . 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.

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

16 . 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.

17 . A hydrophobic metal oxide-silica composite aerogel prepared by the method of claim 1 .

18 . The hydrophobic metal oxide-silica composite aerogel of claim 17 , wherein the aerogel has a specific surface area of 350 m 2 /g to 700 m 2 /g.

19 . The hydrophobic metal oxide-silica composite aerogel of claim 17 , wherein the aerogel has a tap density of 0.051 g/ml to 0.102 g/ml.

20 . The hydrophobic metal oxide-silica composite aerogel of claim 17 , wherein the aerogel has a carbon content of 3.77 wt % to 9.23 wt %.

Assignees

• Lg Chemical Ltd

Inventors

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

Classifications

• C01P2006/11

  Powder tap density · CPC title

• B01J13/0091

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

• C01P2006/90

  Other properties not specified above · CPC title

• C01B33/1585 Primary

  Dehydration into aerogels · CPC title

• C01B33/158 Primary

  Purification; Drying; Dehydrating · CPC title