Methods for preparation of concentrated graphene ink compositions and related composite materials

Patent metadata

Field	Value
Publication number	US-9834693-B2
Application number	US-201414121097-A
Country	US
Kind code	B2
Filing date	Jul 30, 2014
Priority date	Apr 22, 2011
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

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

First claim

We claim:

1. A method of using a cellulosic polymer for preparing a concentrated graphene medium, 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, said dispersing agent at least partially soluble in said organic solvent;
contacting at least a portion of said exfoliated graphene medium with an aqueous medium to concentrate exfoliated graphene in a solid composition comprising graphene and a said cellulosic polymer;
isolating said solid composition from said exfoliating and said aqueous media; and
contacting said solid graphene composition with a hydrophobic fluid component.

2. The method of claim 1 wherein said cellulosic polymer comprises an ethyl cellulose.

3. The method of claim 1 wherein said organic solvent is selected from C 2 - C 5 alcohols, esters, amides, ethers and ketones and combinations thereof.

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

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

6. The method of claim 1 wherein said hydrophobic fluid component comprises a terpineol and cyclohexanone.

7. The method of claim 1 wherein said graphene source material is graphite.

8. The method of claim 1 comprising deposition of said graphene composition on a substrate.

9. The method of claim 8 wherein said graphene composition is annealed.

10. The method of claim 9 wherein said graphene composition is photoannealed.

11. The method of claim 1 wherein said exfoliation comprises shear mixing said graphene source material and said medium.

12. The method of claim 11 wherein said organic solvent is selected from C 2 - C 5 alcohols, esters, amides, ethers and ketones and combinations thereof; and said dispersing agent comprises an ethyl cellulose.

13. A method of preparing a graphene ink composition, said method comprising:
exfoliating a graphene source material with a medium comprising an organic solvent selected from ethanol and dimethylformamide, and an ethyl cellulose;
contacting at least a portion of said exfoliated graphene medium with an aqueous medium to concentrate exfoliated graphene and ethyl cellulose in a solid composition comprising graphene and said ethyl cellulose;
isolating said solid composition from said exfoliating and said aqueous media; and
contacting said solid graphene ethyl cellulose composition with a hydrophobic fluid component to provide a graphene ink composition.

14. The method of claim 13 wherein said exfoliating comprises shear mixing said graphene source material and said medium.

15. The method of claim 13 comprising printing said graphene ink composition on a substrate.

16. The method of claim 15 wherein said graphene ink composition is photoannealed.

Assignees

• Univ Northwestern

Inventors

• Hersam Mark C
• Liang Yu Teng
• Secor Ethan B
• Prabhumirashi Pradyumna L
• Puntambekar Kanan P
• Geier Michael L

Classifications

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C09D11/38 Primary

  characterised by non-macromolecular additives other than solvents, pigments or dyes · CPC title

• C09D11/52

  Electrically conductive inks · CPC title

• H01B1/24

  the conductive material comprising carbon-silicon compounds, carbon or silicon · CPC title

• Y10T428/31786

  Of polyester [e.g., alkyd, etc.] · CPC title