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

Patent metadata

Field	Value
Publication number	US-2017081537-A1
Application number	US-201514756304-A
Country	US
Kind code	A1
Filing date	Aug 24, 2015
Priority date	Apr 22, 2011
Publication date	Mar 23, 2017
Grant date	—

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 preparing an inkjet printed 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 precursor composition comprising graphene and a said cellulose; contacting said graphene-cellulose precursor composition with a hydrophobic fluid component, to provide a graphene ink composition. inkjet printing said graphene ink composition on a substrate; and photonic annealing said graphene ink composition.

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

3 . The method of claim 2 wherein said hydrophobic fluid component comprises a terpineol and cyclohexanone.

4 . The method of claim 1 wherein said graphene ink composition has a graphene concentration of greater than about 3 mg/mL.

5 . The method of claim 4 wherein said graphene ink composition has a graphene concentration of about 20 mg/mL.

6 . The method of claim 5 wherein said graphene ink has a solids content of about 4% w/v.

7 . The method of claim 6 wherein said graphene ink composition has a viscosity of about 8-15 mPa·sec.

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

9 . A method of preparing an inkjet printed 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 to provide a precursor composition comprising graphene and said ethyl cellulose; contacting said graphene-cellulose precursor composition with a hydrophobic fluid component, to provide a graphene ink composition comprising a graphene concentration greater than about 3 mg/mL. inkjet printing said graphene ink composition on a substrate; and photonic annealing said graphene ink composition.

10 . The method of claim 9 wherein said hydrophobic fluid comprises a component selected from terpenes, terpine alcohols and combinations thereof.

11 . The method of claim 10 wherein said hydrophobic fluid component comprises a terpineol and cyclohexanone.

12 . The method of claim 9 wherein said graphene ink composition has a graphene ink concentration of about 20 mg/mL.

13 . The method of claim 12 wherein said graphene ink has a solids content of about 4% w/v.

14 . The method of claim 13 wherein said graphene ink composition has a viscosity of about 8-15 mPa·sec.

15 . The method of claim 9 wherein said exfoliating comprises shear mixing said graphene source material and said medium.

16 . A method of using photonic annealing to prepare a graphene ink composite, said method comprising:
exfoliating a graphene source material with a medium comprising an organic solvent selected from ethanol and dimethylformamide, and an ethyl cellulose to provide a precursor composition comprising graphene and a said ethyl cellulose; contacting said graphene-cellulose precursor composition with a hydrophobic fluid component, to provide a graphene ink composition comprising a solids content of about 4% w/v, a graphene concentration of about 20 mg/mL and a viscosity of about 8-about 15 mPa·sec; inkjet printing said graphene ink composition on a substrate to provide a graphene-substrate composite; and photonic annealing said graphene ink composition.

17 . The method of claim 16 wherein said hydrophobic fluid component comprises a terpineol and cyclohexanone.

18 . The method of claim 16 wherein said precursor composition comprises about 50% wt. graphene and about 50% wt. a said ethyl cellulose.

19 . A composition comprising graphene, a hydrophobic fluid component and an ethyl cellulose dispersing agent at least partially soluble in said hydrophobic fluid component, said composition comprising a graphene concentration greater than about 3 mg/mL.

20 . The composition of claim 19 wherein said hydrophobic fluid component comprises a component selected from terpenes, terpene alcohols and combinations thereof.

21 . The composition of claim 20 wherein said hydrophobic fluid component comprises a terpineol and cyclohexanone.

22 . The composition of claim 19 comprising a graphene concentration of about 20 mg/mL.

23 . The composition of claim 22 comprising a solids content of about 4% w/v and a viscosity of about 8-about 15 mPa·sec.

24 . The composition of claim 19 applied to a substrate and photonically annealed, said applied composition comprising a decomposition product of said ethyl cellulose.

25 . A composite comprising a composition comprising a photonic annealation product of a cellulose-stabilized graphene ink coupled to a substrate, said ink comprising a solids content of about 4% w/v, a graphene concentration of about 20 mg/mL and a viscosity of about 8-about 15 mPa·sec.

26 . The composite of claim 25 wherein said substrate comprises a flexible polymer.

27 . The composite of claim 26 wherein said substrate comprises a polymer selected from a polyimide, polyethylene terephthalate and a polyethylene naphthalate.

28 . The composite of claim 25 incorporated into an electronic device structure

Assignees

• Univ Northwestern
• Harvard College

Inventors

• Hersam Mark C
• Liang Yu Teng
• Secor Ethan B
• Prabhumirashi Pradyumna L
• Puntambekar Kanan P
• Geier Michael L
• Ahn Bok Y
• Lewis Jennifer A

Classifications

• C09D11/322

  Pigment inks · CPC title

• C01B32/19

  by exfoliation · CPC title

• B82Y30/00

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

• B41J2/01

  Ink jet · CPC title

• B41M5/0023

  Digital printing methods characterised by the inks used (inks per se C09D11/00) · CPC title