Enhanced conductivity, adhesion and environmental stability of printed graphene inks with nitrocellulose

Patent metadata

Field	Value
Publication number	US-10280317-B2
Application number	US-201715644326-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 7, 2016
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

Graphene ink compositions comprising nitrocellulose and related methods of use comprising either thermal or photonic annealing.

First claim

We claim:

1. A method of graphene ink deposition, said method comprising:
providing a graphene ink composition comprising graphene, a nitrocellulose and an ink solvent;
depositing said graphene ink composition on a substrate; and
annealing said deposited graphene ink composition, said graphene ink annealation product comprising graphene and amorphous carbon.

2. The method of claim 1 wherein said ink solvent comprises a component selected from C2-C8 alkyl esters, alkylene glycols, alkylene glycol ethers, alkylene glycol acetates, ketones and combinations thereof.

3. The method of claim 1 wherein said deposition is selected from inkjet printing, spray coating and blade coating.

4. The method of claim 3 wherein said ink solvent is selected for a said deposition.

5. The method of claim 4 wherein said deposition is inkjet printing, and said ink solvent comprises ethyl lactate, octyl lactate and ethylene glycol diacetate.

6. The method of claim 4 wherein said deposition is spray coating, and said ink solvent comprises acetone and ethyl lactate.

7. The method of claim 4 wherein said deposition is blade coating, and said ink solvent comprises ethyl lactate.

8. The method of claim 1 wherein said deposition is on a flexible polymeric substrate.

9. The method of claim 1 wherein said deposited graphene ink composition is photonically annealed.

10. The method of claim 9 wherein said deposition is on a substrate selected from glass, metal, metal oxide, paper and flexible polymeric substrates.

11. The method of claim 1 wherein provision of said ink composition comprises:
exfoliating a graphene source material with a medium comprising an organic solvent at least partially miscible with water and a nitrocellulose 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 nitrocellulose;
isolating said solid composition from said media; and
contacting said graphene composition with an ink solvent.

12. A method of using nitrocellulose to modulate properties of a graphene ink printed on a substrate, said method comprising:
providing a graphene ink composition comprising graphene, a nitrocellulose and an ink solvent;
printing said graphene ink composition on a substrate; and
annealing said printed graphene ink composition to decompose said nitrocellulose, thereby providing amorphous carbon and modulating at least one of physical, mechanical and conductive properties of said graphene ink print.

13. The method of claim 12 wherein said amorphous carbon modulates coupling of graphene flakes.

14. The method of claim 12 wherein said amorphous carbon modulates adhesion of said graphene ink print to said substrate.

15. The method of claim 12 wherein said graphene ink composition is printed on a flexible polymeric substrate.

16. The method of claim 12 wherein said ink solvent comprises a component selected from C2-C8 alkyl esters, alkylene glycols, alkylene glycol ethers, alkylene glycol acetates, ketones and combinations thereof.

17. The method of claim 12 wherein said graphene ink composition is annealed at about 200° to about 350° C.

18. The method of claim 17 wherein said graphene ink composition is annealed at 200° C.

19. The method of claim 12 wherein said deposited graphene ink composition is photonically annealed.

20. The method of claim 19 wherein said photonic annealing increases the surface area of said graphene ink print.

21. The method of claim 20 wherein said graphene ink print comprises a porous morphology.

22. The method of claim 19 wherein said substrate is of a microsupercapacitor device, and said printing provides interdigitated graphene electrodes on said substrate.

23. The method of claim 22 wherein said photonic annealing increases capacitance of said device.

24. The method of claim 23 wherein the capacitance of said device increases with increasing thickness dimension of said graphene ink print.

25. A graphene ink composition comprising graphene, a nitrocellulose and an ink solvent, wherein said graphene ink composition is annealed to provide a graphene ink composition comprising graphene and amorphous carbon.

26. The composition of claim 25 wherein said ink solvent comprises a component selected from C2-C8 alkyl esters, alkylene glycols, alkylene glycol ethers, alkylene glycol acetates, ketones and combinations thereof.

27. The composition of claim 25 comprising a graphene concentration of about 1 mg/ml-about 80 mg/ml.

28. The composition of claim 25 comprising a nitrocellulose concentration of about 5 mg/ml-about 15 mg/ml.

29. A composite comprising a graphene ink composition of claim 25 coupled to a flexible polymeric substrate.

30. The composite of claim 29 wherein said substrate comprises a polyimide film.

31. The composite of claim 29 wherein said graphene ink composition is photonically annealed.

32. The composite of claim 31 , wherein said composite is of a microsupercapacitor, and said graphene ink composition provides interdigitated graphene electrodes on said substrate.

33. A graphene ink composition comprising graphene, a nitrocellulose and an ink solvent, said nitrocellulose capable of exothermic decomposition, gaseous evolution upon said decomposition and providing said graphene ink composition a porous microstructure upon said gaseous evolution.

34. The composition of claim 33 wherein said ink solvent comprises a component selected from C2-C8 alkyl esters, alkylene glycols, alkylene glycol ethers, alkylene glycol acetates, ketones and combinations thereof.

35. The composition of claim 33 comprising a graphene concentration of about 1 mg/ml-about 80 mg/ml.

36. The composition of claim 33 comprising a nitrocellulose concentration of about 5 mg/ml-about 15 mg/ml.

37. A composite comprising a graphene ink composition of claim 33 coupled to a flexible polymeric substrate.

38. The composite of claim 37 wherein said substrate comprises a polyimide film.

39. The composite of claim 37 wherein said graphene ink composition is annealed to provide a graphene ink composition comprising graphene and amorphous carbon.

40. The composite of claim 39 wherein said graphene ink composition is photonically annealed.

41. The composite of claim 40 , wherein said composite is of a microsupercapacitor, and said graphene ink composition provides interdigitated graphene electrodes on said substrate.

Assignees

• Univ Northwestern

Inventors

• Hersam Mark C
• Secor Ethan B
• Gao Theodore Z

Classifications

• H05K1/00

  Printed circuits · CPC title

• C09D11/52

  Electrically conductive inks · CPC title

• C09D11/14

  based on carbohydrates · CPC title

• B05D1/02

  performed by spraying · CPC title

• C09D11/322

  Pigment inks · CPC title