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

Patent metadata

Field	Value
Publication number	US-2017305749-A1
Application number	US-201615526221-A
Country	US
Kind code	A1
Filing date	Oct 18, 2016
Priority date	Nov 3, 2015
Publication date	Oct 26, 2017
Grant date	—

Abstract

The present invention relates to a method of preparing a hydrophobic metal oxide-silica composite aerogel, in which a degree of hydrophobicity may be controlled while having a high specific surface area and a low tap density, and a hydrophobic metal oxide-silica composite aerogel prepared thereby. The preparation method according to the present invention 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 perform an effective surface modification reaction by using a small amount of a surface modifier. Thus, since the surface modification reaction may be easily performed by using only a very small amount of the surface modifier, a hydrophobic metal oxide-silica composite aerogel containing about 1 wt % to 2 wt % of carbon may be prepared.

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 to a water glass solution and mixing together to prepare a metal oxide-silica composite gel agglomerate; (2) primarily drying the agglomerate to prepare a powdery metal oxide-silica composite gel; (3) surface-modifying the metal oxide-silica composite gel to prepare a hydrophobic metal oxide-silica composite wet gel; and (4) secondarily drying the hydrophobic metal oxide-silica composite wet gel.

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 (Ca2+) and magnesium ions (Mg2+).

5 . The method of claim 4 , wherein a molar ratio of the calcium ion (Ca2+) to the magnesium ion (Mg2+) 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 0.1 to 1.

7 . The method of claim 1 , wherein, in step 1, an acid catalyst is further added and mixed together.

8 . (canceled)

9 . The method of claim 1 , wherein the primary drying of step 2 is performed by atmospheric pressure drying at a temperature of 100° C. to 150° C. for 1 hour to 2 hours.

10 . The method of claim 1 , further comprising washing the agglomerate with distilled water, alcohol, or a mixture thereof before the primary drying of step 2.

11 . (canceled)

12 . The method of claim 1 , wherein the surface modification of step 3 is performed by dispersing the metal oxide-silica composite gel in a non-polar organic solvent, adding a surface modifier, and performing a reaction.

13 . (canceled)

14 . The method of claim 12 , wherein the surface modifier comprises at least one selected from the group consisting of trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDS), methyltrimethoxysilane, and trimethylethoxysilane.

15 . The method of claim 12 , wherein the surface modifier is added in a molar ratio of 0.01 to 0.5 with respect to water glass.

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

17 . The method of claim 1 , wherein the secondary drying of step (4) is performed by atmospheric pressure drying at a temperature of 100° C. to 150° C. for 1 hour to 4 hours.

18 . A hydrophobic metal oxide-silica composite aerogel having a specific surface area of 350 m 2 /g to 550 m 2 /g, a tap density of 0.08 g/ml to 0.132 g/ml and a carbon content of 1.02 wt % to 10.23 wt % which is prepared by the method of claim 1 .

19 - 21 . (canceled)

Assignees

• Lg Chemical Ltd

Inventors

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

Classifications

• C01B33/1585 Primary

  Dehydration into aerogels · CPC title

• C01B33/158

  Purification; Drying; Dehydrating · CPC title

• C01P2006/10

  Solid density · CPC title

• B01J13/0091

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

• C01P2006/12

  Surface area · CPC title