Solid carbon products comprising carbon nanotubes and methods of forming same

• US 9,604,848 B2
• Filed: 07/09/2013
• Issued: 03/28/2017
• Est. Priority Date: 07/12/2012
• Status: Expired due to Fees

• Current Assignee: Seerstone LLC
• Original Assignee: Seerstone LLC
• Inventors: Noyes, Dallas B.
• Primary Examiner(s): Nguyen, Tri V
• Application Number:
  US14/414,232
• Publication Number:
  US 20150225242A1
• Time in Patent Office: 1,358 Days
• Field of Search: 252500-5191, 423445 R-448, 423/445.B, 977/742, 977/745, 977/842
• US Class Current: 1/1
• CPC Class Codes: B29C 43/006 Pressing and sintering powders, granules or fibres
• CPC Class Codes: B29C 67/24 characterised by the choice of material
• CPC Class Codes: B29K 2105/0014 Catalysts
• CPC Class Codes: B29K 2105/251 Particles, powder or granules expandable particles B29K2105/046
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 32/00 Carbon; Compounds thereof C01B21/00, C01B23/00 take precedence; percarbonates C01B15/10; carbon black C09C1/48
• CPC Class Codes: C01B 32/05 Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
• CPC Class Codes: C01B 32/158 Carbon nanotubes
• CPC Class Codes: C01B 32/159 single-walled
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C01P 2006/90 Other properties not specified above
• CPC Class Codes: C04B 2235/5288 Carbon nanotubes
• CPC Class Codes: C04B 2235/6021 Extrusion moulding
• CPC Class Codes: C04B 2235/604 Pressing at temperatures other than sintering temperatures
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/658 Atmosphere during thermal treatment
• CPC Class Codes: C04B 2235/666 Applying a current during sintering, e.g. plasma sintering [SPS], electrical resistance heating or pulse electric current sintering [PECS]
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 35/645 Pressure sintering
• CPC Class Codes: C04B 35/83 : Carbon fibres in a carbon matrix
• CPC Class Codes: H01B 1/04 : mainly consisting of carbon-silicon compounds, carbon or silicon

Abstract

Methods of forming solid carbon products include disposing a plurality of nanotubes in a press, and applying heat to the plurality of carbon nanotubes to form the solid carbon product. Further processing may include sintering the solid carbon product to form a plurality of covalently bonded carbon nanotubes. The solid carbon product includes a plurality of voids between the carbon nanotubes having a median minimum dimension of less than about 100 nm. Some methods include compressing a material comprising carbon nanotubes, heating the compressed material in a non-reactive environment to form covalent bonds between adjacent carbon nanotubes to form a sintered solid carbon product, and cooling the sintered solid carbon product to a temperature at which carbon of the carbon nanotubes do not oxidize prior to removing the resulting solid carbon product for further processing, shipping, or use.

Claims

1. A method of forming a solid carbon product, the method comprising:

disposing a plurality of carbon nanotubes comprising a residual metal catalyst in a press;

applying pressure to the plurality of carbon nanotubes; and

sintering the plurality of carbon nanotubes at a temperature of at least about 2,100°

C. to form covalent bonds between adjacent carbon nanotubes and produce a sintered solid carbon product comprising the residual metal catalyst and covalently bonded carbon nanotubes.

2. The method of claim 1, further comprising after sintering the plurality of carbon nanotubes, exposing the sintered solid carbon product to at least one reactant selected from the group consisting of metals, metal carbonyls, silanes, and hydrocarbons.

3. The method of claim 1, wherein sintering the plurality of carbon nanotubes comprises sintering the plurality of carbon nanotubes in an inert atmosphere or in a vacuum.

4. The method of claim 1, wherein disposing a plurality of carbon nanotubes comprising a residual metal catalyst in a press comprises disposing a plurality of carbon nanotubes comprising a metal selected from the group consisting of the elements of Groups 5 through 10 of the periodic table in the press.

5. The method of claim 1, wherein applying pressure to the plurality of carbon nanotubes and sintering the plurality of carbon nanotubes to form the sintered solid carbon product comprises forming a porous sintered solid carbon product.

6. The method of claim 1, wherein applying pressure to the plurality of carbon nanotubes and sintering the plurality of carbon nanotubes to form the sintered solid carbon product comprises forming an electrically conductive sintered solid carbon product.

7. The method of claim 6, wherein forming an electrically conductive sintered solid carbon product comprises forming an electrode.

8. The method of claim 1, wherein applying pressure to the plurality of carbon nanotubes and sintering the plurality of carbon nanotubes to form the sintered solid carbon product comprises extruding the sintered solid carbon product through a die.

9. The method of claim 1, wherein applying pressure to the plurality of carbon nanotubes and sintering the plurality of carbon nanotubes to form the sintered solid carbon product comprises pressing the plurality of carbon nanotubes into a mold.

10. The method of claim 1, wherein disposing the plurality of carbon nanotubes in a press comprises disposing the plurality of carbon nanotubes in a mold within the press.

11. The method of claim 1, further comprising:

preparing a liquid solution comprising a salt;

contacting the sintered solid carbon product with the liquid solution;

applying an electric potential to the sintered solid carbon product to induce electrodeposition of at least one component of the liquid solution onto surfaces of the sintered solid carbon product and to form a plated sintered solid carbon product; and

rinsing the plated sintered solid carbon product to remove the liquid solution therefrom.

12. The method of claim 1, wherein the residual metal catalyst comprises at least one material selected from the group consisting of vanadium oxide, palladium, platinum, gold, ruthenium, rhodium, and iridium.

13. The method of claim 1, wherein sintering the plurality of carbon nanotubes comprises sintering the plurality of carbon nanotubes in the presence of a ceramic material selected from the group consisting of boride(s), silicide(s), and combinations thereof.

14. The method of claim 1, further comprising mixing the sintered solid carbon product with at least one material selected from the group consisting of a metal, a ceramic, and a glass to form a material and pressing or pulling the material through a die.

15. The method of claim 1, wherein forming a sintered solid carbon product comprising the residual metal catalyst comprises forming the sintered solid carbon product to have an electrical conductivity of at least about 1×

10⁵ Siemens per meter.