Method of making cohesive carbon assembly and its applications

Patent metadata

Field	Value
Publication number	US-10093544-B2
Application number	US-201514825021-A
Country	US
Kind code	B2
Filing date	Aug 12, 2015
Priority date	Aug 12, 2011
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

Cohesive carbon assemblies are prepared by obtaining a functionalized carbon starting material in the form of powder, particles, flakes, loose agglomerates, aqueous wet cake, or aqueous slurry, dispersing the carbon in water by mechanical agitation and/or refluxing, and substantially removing the water, typically by evaporation, whereby the cohesive assembly of carbon is formed. The method is suitable for preparing free-standing, monolithic assemblies of carbon nanotubes in the form of films, wafers, discs, fiber, or wire, having high carbon packing density and low electrical resistivity. The method is also suitable for preparing substrates coated with an adherent cohesive carbon assembly. The assemblies have various potential applications, such as electrodes or current collectors in electrochemical capacitors, fuel cells, and batteries, or as transparent conductors, conductive inks, pastes, and coatings.

First claim

What is claimed:

1. A method of preparing a cohesive carbon assembly comprising:
a. obtaining a functionalized carbon starting material in a form of powder, particles, flakes, loose agglomerates, aqueous wet cake, or aqueous slurry; said functionalized carbon starting material is a carbon starting material which has been covalently or non-covalently functionalized such that it is dispersible in water;
b. dispersing the functionalized carbon starting material in an aqueous solution in a prescribed ratio to form a dispersion;
c. applying the dispersion to a hydrophilic surface such that after one application, the applied dispersion has a thickness of about 0.02 to about 2,000 μm, wherein the hydrophilic surface is selected from the group consisting of: a metal surface, a glass surface, a silicon surface, a plastic surface, and a ceramic surface; and
d. removing greater than 99% of the liquid portion from the dispersion in a controlled manner by evaporation without a mechanical force to form a cohesive carbon assembly having a monolithic structure.

2. The method of claim 1 , wherein the carbon starting material is selected from the group consisting of carbon nanotubes, graphene, graphene oxide, graphite, expanded graphite, exfoliated graphite, amorphous carbon, activated carbon, and any combinations thereof.

3. The method of claim 2 , wherein the functionalized carbon starting material contains acyl chloride, carboxyl, hydroxyl, amide, glycerol, organic ester, polyethylene oxide, polyethylene glycol, polyvinyl acetate, amino terminated polystyrene, bovine serum albumin, m-polyaminobenzene sulfonic acid, or any combination thereof.

4. The method of claim 3 , wherein the functionalized carbon starting material contains carboxyl, hydroxyl, amide, or glycerol.

5. The method of claim 2 , wherein the carbon starting material is carbon nanotubes.

6. The method of claim 1 , wherein the carbon starting material is single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, or any combination thereof.

7. The method of claim 1 , wherein the aqueous solution is de-ionized water, distilled water, purified water, or any combination thereof.

8. The method of claim 1 , wherein step b comprises dispersing the functionalized carbon starting material in water in the presence of mechanical agitation.

9. The method of claim 8 , wherein the mechanical agitation comprises sonication, mechanical stirring, shear mixing, microfluidization, homogenization, or any combination thereof.

10. The method of claim 1 , wherein the functionalized carbon starting material is functionalized single-walled carbon nanotubes, the water is purified and de-ionized water, and the ratio of carbon starting material and water is between about 0.1 and about 20 mg carbon per gram of water.

11. The method of claim 1 , wherein the functionalized carbon starting material is dispersed in the aqueous solution that is substantially free of a binding material or a surfactant.

12. The method of claim 1 , wherein the dispersion is applied to the hydrophilic surface by casting.

13. The method of claim 1 , wherein the hydrophilic surface is a metal surface.

14. The method of claim 13 , wherein the metal is selected from the group consisting of aluminum, copper, gold, silver, platinum, tantalum, titanium, stainless steel, and any combination thereof.

15. The method of claim 1 , wherein the dispersion is applied to the hydrophilic surface by spin-coating, dip-coating, flow-coating, spray coating, casting, or any combination thereof.

16. A method of preparing a cohesive carbon assembly comprising:
a. obtaining a functionalized carbon starting material in a form of powder, particles, flakes, loose agglomerates, aqueous wet cake, or aqueous slurry; said functionalized carbon starting material is a carbon starting material which has been covalently or non-covalently functionalized such that it is dispersible in water;
b. dispersing the functionalized carbon starting material in an aqueous solution in a prescribed ratio to form a dispersion;
c. applying the dispersion to an inner surface of a container such that after one application, the applied dispersion has a thickness of about 0.02 to about 2,000 μm; and
d. removing greater than 99% of the liquid portion from the dispersion in a controlled manner by evaporation without a mechanical force to form a cohesive carbon assembly having a monolithic structure inside the container.

17. The method of claim 16 , further comprises removing and transferring the formed cohesive carbon assembly from the container.

18. The method of claim 16 , wherein the inner surface of the container is a hydrophobic surface comprising a dimethyl organosilane, a fluorinated dimethyl organosilane, a fluorinated polymer, a polytetrafluoroethylene coating, or a combination thereof.

19. The method of claim 16 , wherein the inner surface of the container is a hydrophilic surface selected from the group consisting of: a metal surface, a glass surface, a silicon surface, a plastic surface, and a ceramic surface.

20. The method of claim 16 , wherein the functionalized carbon starting material contains acyl chloride, carboxyl, hydroxyl, amide, glycerol, organic ester, polyethylene oxide, polyethylene glycol, polyvinyl acetate, amino terminated polystyrene, bovine serum albumin, m-polyaminobenzene sulfonic acid, or any combination thereof.

Assignees

• Yazaki Corp

Inventors

• Grigorian Leonid
• Brahim Sean Imtiaz

Classifications

• C01B32/174 Primary

  Derivatisation; Solubilisation; Dispersion in solvents · CPC title

• Y10T428/26

  Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension · CPC title

• B82Y30/00

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

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title