Method and apparatus for producing carbon nanostructures

• US 7,550,128 B2
• Filed: 07/09/2004
• Issued: 06/23/2009
• Est. Priority Date: 07/09/2004
• Status: Active Grant

• Current Assignee: Clean Technology International Corp.
• Original Assignee: Clean Technology International Corp.
• Inventors: Wagner, Anthony S.
• Primary Examiner(s): Hendrickson; Stuart L.
• Assistant Examiner(s): MCCRACKEN, DANIEL
• Application Number:
  US10/887,695
• Publication Number:
  US 20060008405A1
• Time in Patent Office: 1,810 Days
• Field of Search: 423/445.B, 423/460, 423/461, 423/DIG.12, 423/447.1, 423/447.3, 110/235, 110/237, 110/243, 977/842, 977/844
• US Class Current: 423/445.00B
• CPC Class Codes: B01J 19/006 Baffles
• CPC Class Codes: B01J 2219/00763 Baffles
• CPC Class Codes: B01J 2219/00768 vertical
• CPC Class Codes: B01J 4/002 Nozzle-type elements nozzle-type reactors B01J19/26
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/04 Nanotubes with a specific amount of walls
• CPC Class Codes: C01B 32/166 in liquid phase
• CPC Class Codes: C01B 32/18 Nanoonions; Nanoscrolls; Nanohorns; Nanocones; Nanowalls
• CPC Class Codes: Y10S 977/842 for carbon nanotubes or fullerenes
• CPC Class Codes: Y10S 977/844 Growth by vaporization or dissociation of carbon source using a high-energy heat source, e.g. electric arc, laser, plasma, e-beam

Abstract

A method includes liberating carbon atoms from hydrocarbon molecules by reaction with or in a reactant liquid and maintaining the liberated carbon atoms in an excited state. The chemically excited liberated carbon atoms are then enabled to traverse a surface of the reactant liquid and are directed across a collection surface. The collection surface and the conditions at and around the collection surface are maintained so that the liberated carbon atoms in the excited state phase change to a ground state by carbon nanostructure self-assembly.

Claims

1. A method for producing carbon nanostructures, the method including:

(a) producing a collection atmosphere within a collection chamber which defines a collection area above a reactant liquid;

(b) injecting a feed material into the reactant liquid, the feed material comprising a quantity of a first type of hydrocarbon compound;

(c) maintaining the hydrocarbon molecules of the first type of hydrocarbon compound and any reaction products in contact with the reactant liquid for a period of time sufficient to liberate carbon atoms from the hydrocarbon molecules of the first type of hydrocarbon compound or reaction products and place the liberated carbon atoms in an excited state;

(d) enabling the liberated carbon atoms in the excited state to traverse a surface of the reactant liquid and flow through the collection area so that the liberated carbon atoms pass over a collection surface within the collection chamber under conditions in which the liberated carbon atoms are enabled to phase change to the ground state;

(e) collecting carbon nanostructures on the collection surface as the liberated carbon atoms phase change to the ground state at the collection surface;

(f) removing the collection surface from the collection chamber; and

(g) removing carbon nanostructures from the collection surface after the collection surface is removed from the collection chamber.

2. The method of claim 1 wherein the collection surface is maintained at a temperature between approximately 600 degrees Celsius to approximately 950 degrees Celsius.

3. The method of claim 1 wherein the reactant liquid includes liquid aluminum at a temperature at or above 650 degrees Celsius.

4. The method of claim 1 wherein the step of producing the collection atmosphere includes purging the collection area of oxygen.

5. The method of claim 1 further including the step of maintaining a turbulent flow regime in gasses flowing across the collection surface.

6. The method of claim 1 wherein the collection atmosphere includes one or more purge gases selected from a group consisting of nitrogen, helium, argon, carbon monoxide, and heater burner flue gasses.

7. The method of claim 1 wherein the step of maintaining the hydrocarbon molecules and any reaction products in contact with the reactant liquid includes placing the hydrocarbon molecules and reaction products in contact with the reactant liquid under a pressure of at least approximately 2.4 psig.

8. The method of claim 1 wherein the step of maintaining the hydrocarbon molecules and any reaction products in contact with the reactant liquid includes trapping the hydrocarbon molecules and reaction products in a reaction chamber having an upper surface below the surface of the reactant liquid.

9. The method of claim 1 wherein the step of injecting the hydrocarbon molecules into the reactant liquid comprises injecting the hydrocarbon into a bath of reactant liquid at a depth sufficient to produce at least approximately 2.4 psig of pressure on the injected hydrocarbon molecules by the column of reactant liquid above the hydrocarbon molecules.

10. The method of claim 1 further including the step of positioning a seed material on the collection surface.

11. The method of claim 10 wherein the seed material includes a carbon nanostructure.

12. A method for producing carbon nanostructures, the method including:

(a) liberating carbon atoms from hydrocarbon molecules by reduction reaction with a reactant liquid and maintaining the liberated carbon atoms in an excited state; and

(b) enabling the liberated carbon atoms in the excited state to traverse a surface of the reactant liquid into a collection chamber which defines a volume above the reactant liquid;

(c) directing the liberated carbon atoms in the excited state across a collection surface within the collection chamber under collection conditions at which the liberated carbon atoms in the excited state phase change to a ground state by carbon nanostructure self-assembly;

(d) collecting carbon nanostructures on the collection surface as the liberated carbon atoms phase change to the ground state by carbon nanostructure self-assembly;

(e) removing the collection surface from the collection chamber; and

(f) removing carbon nanostructures from the collection surface after the collection surface is removed from the collection chamber.

13. The method of claim 12 further including the step of directing the liberated carbon atoms in the excited state across at least one seed material on the collection surface.

14. The method of claim 12 further including the step manipulating the flow of gasses traversing the surface of the reactant liquid to produce a low pressure area adjacent to the collection surface.

15. The method of claim 12 further including the step of maintaining the collection surface at a temperature of between approximately 600 degrees Celsius to approximately 950 degrees Celsius.

16. The method of claim 12 wherein the reactant liquid includes predominantly aluminum at a temperature of approximately 950 degrees Celsius.

17. The method of claim 16 further including the step of maintaining the hydrocarbon molecules and reaction products under a pressure of at least approximately 2.4 psig prior to traversing the surface of the reactant liquid.

18. The method of claim 12 wherein the step of directing the liberated carbon atoms in the excited state across the collection surface includes deflecting the liberated carbon atoms along a flow path transverse to a line extending perpendicular to the reactant liquid surface and wherein the deflection is accomplished no further than approximately three feet from the level of the reactant liquid surface.

19. The method of claim 12 further including the step of securing one or more types of seed materials on the collection surface prior to directing the liberated carbon atoms in the excited state across the collection surface.

20. The method of claim 12 wherein the step of liberating carbon atoms from hydrocarbon molecules includes trapping the hydrocarbon molecules and other reaction products in a reaction chamber having an upper surface below the surface of the reactant liquid.

21. The method of claim 20 further including the step of directing the liberated carbon atoms in the excited state and other reaction products around a blocking structure extending into the reactant liquid.

22. The method of claim 21 wherein the collection surface comprises an upper surface of the blocking structure and the upper surface of the blocking structure resides above a level of the reactant liquid.

23. An apparatus including:

(a) a reactant liquid vessel for containing a reactant liquid at a reactant liquid level;

(b) a collection chamber defined by collection chamber walls and positioned to receive effluent escaping from the reactant liquid in the reactant liquid vessel;

(c) an injection arrangement for injecting a stream of feed material into the reactant liquid vessel at an injection point below the reactant liquid level and laterally spaced apart from the collection chamber;

(d) an elongated reaction chamber defining a flow path for feed material and reaction products from the injection point to a location below the collection chamber; and

(e) a number of collection structures mounted in the collection chamber, each collection structure providing a respective collection surface within the collection chamber, the collection surfaces residing at a position above the reactant liquid level in the collection chamber and being separate from the collection chamber walls.

24. The apparatus of claim 23 wherein at least one of the collection surfaces includes a portion extending in a plane transverse to a device vertical axis.

25. The apparatus of claim 24 wherein the portion of a respective collection surface extending in the plane transverse to the device vertical axis includes a portion located no more than approximately three feet above the reactant liquid level of the reactant liquid vessel.

26. The apparatus of claim 23 further including at least one seed object on a respective one of the collection surfaces.

27. The apparatus of claim 23 further including a deflecting surface forming a portion of the collection chamber, the deflection surface extending transverse to the device vertical axis in position to deflect effluent escaping from the reactant liquid so that the effluent flows across one or more of the collection surfaces.

28. The apparatus of claim 23 further including a flow channel formed at an outlet end of the reaction chamber, and a blocking structure positioned directly above the flow channel and below the reactant liquid level in the reactant liquid vessel.

29. The apparatus of claim 23 wherein at least one collection surface comprises an upper surface of a respective one of the collection structures and the respective collection structure has a lower surface located below the reactant liquid level, the lower surface extending transverse to a device vertical axis.

30. The apparatus of claim 23 wherein at least one collection surface includes graphite.