Method of producing graphene

Patent metadata

Field	Value
Publication number	US-11261092-B2
Application number	US-201916358773-A
Country	US
Kind code	B2
Filing date	Mar 20, 2019
Priority date	Mar 28, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

The invention provides a method of producing graphene. The method comprising: A) mixing graphite powders with a silk fibroin nanofiber solution, performing mechanical stirring to exfoliate graphite to form graphene flakes; wherein the silk fibroin nanofibers in the silk fibroin nanofiber solution have a crystallinity of 40% or above; the silk fibroin nanofibers have a diameter of 10 to 30 nm; the silk fibroin nanofibers have a length of 100 nm to 3 μm; the mechanical stirring has a shearing speed of 1,000 to 50,000 rpm; and the duration of the mechanical stirring is 10 min to 6 h; B) centrifuging the solution obtained in step A) after exfoliation to remove unexfoliated graphite; and C) centrifuging the centrifuged solution obtained in step B), and separating graphene from the silk fibroin nanofibers to obtain the graphene.

First claim

What is claimed is:

1. A method of producing graphene, comprising:
A) mixing graphite powders with a silk fibroin nanofiber solution, performing mechanical stirring to exfoliate graphite to form graphene flakes;
wherein the silk fibroin nanofibers in the silk fibroin nanofiber solution have a crystallinity of 40% or above; the silk fibroin nanofibers have a diameter of 10 to 30 nm; the silk fibroin nanofibers have a length of 100 nm to 3 μm;
wherein the mechanical stirring has a shearing speed of 20,000 to 50,000 rpm; and the duration of the mechanical stirring is 10 min to 6 h; and
wherein the mechanical stirring is performed at the temperature of 10 to 40° C. and in a device with a volume of 1 to 100 L;
B) centrifuging the solution obtained in step A) after exfoliation to remove unexfoliated graphite; and
C) centrifuging the centrifuged solution obtained in step B), and separating graphene from the silk fibroin nanofibers to obtain the graphene.

2. The method according to claim 1 , wherein the silk fibroin nanofibers has a beta-sheet crystal structure.

3. The method according to claim 1 , wherein the silk fibroin nanofiber solution has a mass concentration of 0.1 to 3%.

4. The method according to claim 1 , wherein the mass ratio of the dry silk fibroin nanofibers used to prepare the silk fibroin nanofiber solution to the graphite powders is 1: (1 to 100).

5. The method according to claim 1 , wherein the centrifuging in step B) is performed at the speed of 500 to 5,000 rpm; and
the duration of the centrifuging in step B) is 5 min to 2 h.

6. The method according to claim 1 , wherein the centrifuging in step C) is performed at the speed of 8,000 to 20,000 rpm; and
the duration of the centrifuging in step C) is 5 to 60 min.

7. The method according to claim 1 , wherein the graphene has 5 layers or fewer and a lateral size of 100 nm to 2 μm.

Assignees

• Univ Soochow

Inventors

• Lu Qiang
• Zhang Xiaoyi
• Xiao Liying

Classifications

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01B2204/32

  Size or surface area · CPC title

• C01P2002/01

  depicted by a TEM-image · CPC title

• C01B2204/04

  Specific amount of layers or specific thickness · CPC title

• C01B32/192 Primary

  starting from graphitic oxides · CPC title