Methods for preparation of concentrated graphene compositions and related composite materials

Patent metadata

Field	Value
Publication number	US-10494536-B2
Application number	US-201816042251-A
Country	US
Kind code	B2
Filing date	Jul 23, 2018
Priority date	Apr 22, 2011
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

A rapid, scalable methodology for graphene dispersion with a polymer-organic solvent solution and subsequent solvent exchange, as can be utilized without centrifugation, to enhance graphene concentration.

First claim

We claim:

1. A method of using a cellulosic polymer to provide concentrated graphene in preparation of a graphene ink composition, said method comprising:
exfoliating a graphene source material with a medium comprising an organic solvent at least partially miscible with water and a dispersing agent comprising a cellulosic polymer at least partially soluble in said organic solvent, said graphene source material not oxidized wherein said graphene source material is a graphite and, wherein said organic solvent is selected from C 2 -C 5 alcohols, esters, amides, ethers and ketones and combinations thereof;
contacting at least a portion of said exfoliated graphene medium with a hydrophobic fluid component; and
hydrating said exfoliated graphene medium to concentrate said exfoliated graphene in said hydrophobic fluid component, said concentrated graphene medium is achieved without application of centrifugal force.

2. The method of claim 1 wherein said dispersing agent comprises an ethyl cellulose.

3. The method of claim 1 wherein said organic solvent is selected from ethanol, methylpyrrolidone and dimethylformamide.

4. The method of claim 1 wherein said hydrophobic fluid component is selected from terpenes, terpene alcohols and combinations thereof.

5. The method of claim 4 wherein said hydrophobic fluid component comprises a terpineol.

6. The method of claim 1 further comprising iterative separation of said graphene-hydrophobic fluid component from said organic solvent and contact with another portion of said exfoliated graphene medium, to provide a graphene ink composition.

7. The method of claim 6 comprising application of said graphene ink medium on a substrate.

8. The method of claim 7 wherein said graphene ink medium is annealed to remove said dispersing agent.

9. A method of using a cellulosic polymer to prepare a graphene ink composition, said method comprising:
exfoliating a graphene source material with a medium comprising an organic solvent at least partially miscible with water and a dispersing agent comprising a cellulosic polymer at least partially soluble in said organic solvent, said graphene source material not oxidized;
contacting at least a portion of said exfoliated graphene medium with a hydrophobic fluid component;
hydrating said exfoliated graphene medium to concentrate said exfoliated graphene in said hydrophobic fluid component, said concentrated graphene medium is achieved without application of centrifugal force; and
iteratively separating said graphene-hydrophobic fluid component from said organic solvent and contact with another portion of said exfoliated graphene medium, to provide a graphene ink composition.

10. The method of claim 9 wherein said dispersing agent comprises an ethyl cellulose.

11. The method of claim 9 wherein said organic solvent is selected from C 2 -C 5 alcohols, esters, amides, ethers and ketones and combinations thereof.

12. The method of claim 11 wherein said organic solvent is selected from ethanol, methylpyrrolidone and dimethylformamide.

13. The method of claim 9 wherein said hydrophobic fluid component is selected from terpenes, terpene alcohols and combinations thereof.

14. The method of claim 13 wherein said hydrophobic fluid component comprises a terpineol.

15. The method of claim 9 wherein said graphene source material is a graphite.

16. The method of claim 9 comprising application of said graphene ink medium on a substrate.

17. The method of claim 16 wherein said graphene ink medium is annealed to remove said dispersing agent.

Assignees

• Univ Northwestern

Inventors

• Hersam Mark C
• Liang Yu Teng

Classifications

• C09D11/52

  Electrically conductive inks · CPC title

• C08K5/20

  Carboxylic acid amides · CPC title

• C08K3/042

  Graphene or derivatives, e.g. graphene oxides · CPC title

• C08K5/3415

  Five-membered rings · CPC title

• C01B32/174

  Derivatisation; Solubilisation; Dispersion in solvents · CPC title