Highly porous aerogels

Patent metadata

Field	Value
Publication number	US-10875003-B2
Application number	US-201414899926-A
Country	US
Kind code	B2
Filing date	Jul 1, 2014
Priority date	Jul 9, 2013
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

Provided are methods for the manufacture of highly porous aerogels, particularly to twisted carbon fibers (TCF) and carbon microbelt (CMB) aerogels, by providing a carbon raw material and heating said carbon raw material under inert gas atmosphere and reduced pressure up to 900 ° C. Also encompassed are the thus obtained aerogels and the use thereof, particularly for treating waste water.

First claim

The invention claimed is:

1. A method for manufacturing a twisted carbon fiber (TCF) porous, hydrophobic aerogel, the method comprising:
(i) providing cotton comprising fibers having a twisted structure; and
(ii) heating the cotton under inert gas atmosphere and at a reduced pressure of about 0.1 mbar to about 500 mbar to any temperature from about 200° C. up to 900° C., thereby decomposing the cotton and producing the twisted carbon fiber (TCF) porous, hydrophobic aerogel.

2. The method according to claim 1 , wherein the cotton comprises cellulosic material of Formula (I)

wherein,
n is from 25 to 10,000, preferably from 50 to 5,000, and
R 1 is hydrogen.

3. The method according claim 1 , wherein step (ii) is conducted at a pressure of about 0.25 mbar to about 250 mbar, or of about 0.5 mbar to about 100 mbar.

4. The method according to claim 1 , wherein step (i) comprises washing and/or drying the cotton.

5. The method according to claim 4 , wherein deionized water is used for washing in step (i).

6. The method according to claim 4 , wherein drying in step (i) is conducted at a temperature from about 10° C. to about 200° C., from about 20° C. to about 150° C., or from about 40° C. to about 90° C.

7. The method according to claim 4 , wherein drying is conducted under reduced pressure.

8. The method according to claim 1 , wherein step (ii) comprises heating to a temperature, from about 400° C. to about 900° C., from about 600° C. to about 900° C., from about 700° C. to about 900° C., from about 750° C. to about 850° C. or of about 800° C.

9. The method according to claim 1 , wherein step (ii) comprises heating for a time period of from about 0.1 hour to about 12 hours, from about 0.1 hour to about 8 hours, from about 0.25 hour to about 6 hours, from about 0.5 hour to about 4 hours, from about 1 hour to about 3 hours, or of about 2 hours.

10. The method according to claim 1 , wherein the heating rate in step (ii) is from about 0.1° C/min to about 20° C/min, from about 1° C/min to about 15° C/min, from about 1.5° C/min to about 10° C/min, from about 2° C/min to about 8° C/min, from about 4° C/min to about 6° C/min, or about 5° C/min.

11. The method according to claim 1 , wherein the method comprises pretreating the cotton.

12. The method according to claim 11 , wherein pretreating comprises pretreating the cotton with water and/or an aqueous solution.

13. The method according to claim 12 , wherein the aqueous solution comprises an acid.

Assignees

• Univ Nanyang Tech

Inventors

• Zhang Hua
• Bi Hengchang

Classifications

• C02F1/281

  using inorganic sorbents · CPC title

• B01J20/28047

  Gels · CPC title

• C09K3/32

  for absorbing liquids to remove pollution, e.g. oil, gasoline, fat · CPC title

• B01J20/28054

  characterised by their surface properties or porosity · CPC title

• B01J20/3078

  Thermal treatment, e.g. calcining or pyrolizing · CPC title