Block copolymer, and method for preparing graphene using same

Patent metadata

Field	Value
Publication number	US-11192085-B2
Application number	US-202017005540-A
Country	US
Kind code	B2
Filing date	Aug 28, 2020
Priority date	Dec 12, 2014
Publication date	Dec 7, 2021
Grant date	Dec 7, 2021

Abstract

The present invention relates to a method for preparing graphene using a novel block copolymer. The present invention has features that, by using the block copolymer to mediate graphene that is hydrophobic and a solvent of a feed solution that is hydrophilic, the exfoliation efficiency of graphene as well as the dispersion stability thereof can be increased during high-pressure homogenization.

First claim

The invention claimed is:

1. A method for preparing graphene, comprising the step of passing a feed solution including graphite through a high-pressure homogenizer including an inlet, an outlet, and a micro-channel that connects between the inlet and the outlet and has a diameter in a micrometer scale,
wherein the feed solution includes a block copolymer comprising a repeating unit represented by the following Chemical Formula 1 and a repeating unit represented by the following Chemical Formula 2:

in Chemical Formula 1,
X is a bond or oxygen,
R 1 and R 2 are each independently hydrogen; C 1-4 alkyl; carboxy group; or C 6-20 aryl substituted with a carboxy group or a sulfonic acid group, provided that when X is a bond, R 2 is not hydrogen and C 1-4 alkyl,
n is an integer of 1 to 10,000, and
n′ is an integer of 0 to 2,

in Chemical Formula 2,
R 3 and R 4 are each independently hydrogen; C 6-20 aryl; —COO—(C 6-20 aryl); or —COO—(C 1-4 alkylene)-(C 6-20 aryl), and
m is an integer of 1 to 10,000.

2. The method for preparing graphene according to claim 1 , wherein
the block copolymer is represented by the following Chemical Formula 3:

in Chemical Formula 3,
X is a bond or oxygen,
R 1 and R 2 are each independently hydrogen; C 1-4 alkyl; carboxy group; or C 6-20 aryl substituted with a carboxy group or a sulfonic acid group, provided that when X is a bond, R 2 is not hydrogen and C 1-4 alkyl,
R 3 and R 4 are each independently hydrogen; C 6-20 aryl; —COO—(C 6-20 aryl); or —COO—(C 1-4 alkylene)-(C 6-20 aryl),
n is an integer of 1 to 10,000, and
m is an integer of 1 to 10,000.

3. The method for preparing graphene according to claim 2 , wherein
X is a bond,
R 1 is hydrogen; or C 1-4 alkyl, and
R 2 is a carboxy group; or C 6-20 aryl substituted with a carboxyl group or a sulfonic acid group.

4. The method for preparing graphene according to claim 2 , wherein
X is oxygen and
R 1 and R 2 are each independently hydrogen.

5. The method for preparing graphene according to claim 2 , wherein
R 1 and R 2 are each independently hydrogen; methyl; carboxy group; or phenyl substituted with a sulfonic acid group, and
R 3 and R 4 are each independently hydrogen; phenyl; naphthyl; pyrene-2-ylmethoxycarbonyl; or 4-(pyrene-2-yl)butoxycarbonyl.

6. The method for preparing graphene according to claim 1 , wherein
the block copolymer is represented by the following chemical formula:

7. The method for preparing graphene according to claim 1 , wherein
the ratio of n:m is 2-10:1.

8. The method for preparing graphene according to claim 1 , wherein
the block copolymer includes a repeating unit represented by the following Chemical Formula 4 and a repeating unit represented by the following Chemical Formula 5:

in Chemical Formula 4,
X′ is C 1-3 alkylene, and
n is an integer of 1 to 10,000,

in Chemical Formula 5,
R 4 is C 6-20 aryl, or —COO—(C 1-4 alkylene)-(C 6-20 aryl), and
m is an integer of 1 to 10,000.

9. The method for preparing graphene according to claim 8 , wherein
X′ is ethylene (—CH 2 —CH 2 —).

10. The method for preparing graphene according to claim 8 , wherein
R 4 is phenyl, naphthyl, or —COOCH 2 -(pyrenyl).

11. The method for preparing graphene according to claim 8 , wherein
the block copolymer is represented by the following Chemical Formula 6:

in Chemical Formula 6,
R′ is C 1-3 alkoxy,
X′, R 4 , n and m are as defined in claim 8 .

12. The method for preparing graphene according to claim 1 , wherein
the graphite in the feed solution is exfoliated while passing through the micro-channel under application of a shear force, thereby preparing the graphene.

13. The method for preparing graphene according to claim 1 , wherein
the micro-channel has a diameter of 10 to 800 μm.

14. The method for preparing graphene according to claim 1 , wherein
the feed solution is introduced in the inlet of the high-pressure homogenizer under application of a pressure of 100 to 3,000 bar and passed through the micro-channel.

15. The method for preparing graphene according to claim 1 , wherein
a solvent of the feed solution is one or more selected from the group consisting of water, NMP (N-methyl-2-pyrrolidone), acetone, DMF (N,N-dimethylformamide), DMSO (dimethyl sulfoxide), CHP (cyclohexyl-pyrrolidinone), N12P (N-dodecyl-pyrrolidone), benzyl benzoate, N8P (N-octyl-pyrrolidone), DMEU (dimethyl-imidazolidinone), cyclohexanone, DMA (dimethylacetamide), NMF (N-methyl formamide), bromobenzene, chloroform, chlorobenzene, benzonitrile, quinoline, benzyl ether, ethanol, isopropyl alcohol, methanol, butanol, 2-ethoxyethanol, 2-butoxyethanol, 2-methoxypropanol, THF (tetrahydrofuran), ethylene glycol, pyridine, N-vinylpyrrolidone, methyl ethyl ketone (butanone), alpha-terpineol, formic acid, ethyl acetate and acrylonitrile.

16. The method for preparing graphene according to claim 1 , wherein
the step of passing the material recovered in the inlet through the micro-channel is additionally repeated once to 9 times.

Assignees

• Lg Chemical Ltd
• Seoul Nat Univ R&Db Foundation

Inventors

• Lee Mi Jin
• Sohn Byeong-Hyeok
• Chae seung yong
• Kwon Won Jong
• Sohn Kwon Nam

Classifications

• C08F293/005

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• C08F293/00 Primary

  Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule (on to polymers modified by introduction of unsaturated end groups C08F290/02) · CPC title

• C08F212/08

  Styrene · CPC title

• C01B2204/32

  Size or surface area · CPC title

• B01J2219/00891

  Feeding or evacuation · CPC title