Continuous process for the production of nanostructures including nanotubes

Patent metadata

Field	Value
Publication number	US-9394175-B2
Application number	US-201514858981-A
Country	US
Kind code	B2
Filing date	Sep 18, 2015
Priority date	May 19, 2006
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

The present invention provides methods for uniform growth of nanostructures such as nanotubes (e.g., carbon nanotubes) on the surface of a substrate, wherein the long axes of the nanostructures may be substantially aligned. The nanostructures may be further processed for use in various applications, such as composite materials. For example, a set of aligned nanostructures may be formed and transferred, either in bulk or to another surface, to another material to enhance the properties of the material. In some cases, the nanostructures may enhance the mechanical properties of a material, for example, providing mechanical reinforcement at an interface between two materials or plies. In some cases, the nanostructures may enhance thermal and/or electronic properties of a material. The present invention also provides systems and methods for growth of nanostructures, including batch processes and continuous processes.

First claim

What is claimed:

1. A method of growing nanostructures, comprising:
exposing a first portion of a porous growth substrate, with a surface on a first side of the porous growth substrate comprising a catalyst material, to a set of conditions selected to cause catalytic formation of nanostructures on the surface, wherein a nanostructure precursor material used in the formation of the nanostructures is transported from a second side of the porous growth substrate to the first side of the porous growth substrate;
while exposing the first portion of the growth substrate to the set of conditions, removing nanostructures from a second portion of the surface of the growth substrate; and
repeating the exposing and removing acts with said growth substrate at least one time.

2. A method as in claim 1 , wherein the nanostructure is a nanotube.

3. A method as in claim 1 , wherein the nanostructure is a carbon nanotube.

4. A method as in claim 1 , wherein the act of removing comprises removing the nanostructures without attaching the nanostructures to a receiving substrate.

5. A method as in claim 1 , wherein the act of removing comprises application of a mechanical tool, mechanical vibration, a chemical reagent, and/or heat to the nanostructures and/or the surface of the growth substrate.

6. A method as in claim 1 , wherein the growth substrate is a cylindrical substrate.

7. A method as in claim 1 , wherein the growth substrate comprises alumina, silicon, carbon, a ceramic, and/or a metal.

8. A method as in claim 1 , wherein the act of exposing comprises flowing the nanostructure precursor material through the porous growth substrate.

9. A method of growing nanostructures, comprising:
exposing a first portion of a growth substrate with a surface comprising a first catalyst material to a first set of conditions selected to cause catalytic formation of nanostructures on the surface; and
while exposing the first portion of the growth substrate to the first set of conditions, treating a second portion of the growth substrate to a second set of conditions selected to reactivate catalyst material on a surface of the second portion of the growth substrate.

10. A method as in claim 9 , wherein the nanostructure is a nanofiber.

11. A method as in claim 9 , wherein the nanostructure is a nanotube.

12. A method as in claim 9 , wherein the nanostructure is a carbon nanotube.

13. A method as in claim 9 , further comprising removing the nanostructures from at least a portion of the surface of the growth substrate.

14. A method as in claim 9 , wherein the growth substrate is porous.

15. A method as in claim 14 , wherein the act of exposing comprises flowing a nanostructure precursor material through the porous growth substrate.

16. A method as in claim 15 , wherein the nanostructure precursor material comprises a hydrocarbon.

17. A method as in claim 14 , wherein the act of exposing comprises flowing a chemical species through the porous growth substrate to treat the catalyst material.

18. A method as in claim 17 , wherein the chemical species reduces or oxidizes the catalyst material after growth of the nanostructures.

19. A method as in claim 9 , wherein the nanostructures are arranged on and/or in the surface, such that the long axes of the nanostructures are substantially aligned and non-parallel to the surface.

20. A method as in claim 9 , further comprising adding one or more support materials to the nanostructures.

21. A method as in claim 9 , wherein the nanostructure is a nanowire.

22. A method of growing nanostructures, comprising:
exposing a growth substrate with a surface comprising a catalyst material to a first set of conditions selected to cause catalytic formation of nanostructures on the surface;
removing nanostructures from the surface of the growth substrate; and
treating the growth substrate to a second set of conditions selected to reactivate the catalyst material.

23. A method as in claim 22 , wherein the nanostructure is a nanofiber.

24. A method as in claim 22 , wherein the nanostructure is a nanotube.

25. A method as in claim 22 , wherein the nanostructure is a carbon nanotube.

26. A method as in claim 22 , wherein the growth substrate is a cylindrical substrate.

27. A method as in claim 22 , wherein the growth substrate is porous.

28. A method as in claim 27 , wherein the act of exposing comprises flowing a nanostructure precursor material through the porous growth substrate.

29. A method as in claim 28 , wherein the nanostructure precursor material comprises a hydrocarbon.

30. A method as in claim 27 , wherein the act of exposing comprises flowing a chemical species through the porous growth substrate to treat the catalyst material.

31. A method as in claim 30 , wherein the chemical species re-activates the catalyst material after growth of the nano structures.

32. A method as in claim 30 , wherein the chemical species reduces or oxidizes the catalyst material after growth of the nanostructures.

33. A method as in claim 22 , wherein the nanostructures are arranged on and/or in the surface, such that the long axes of the nanostructures are substantially aligned and non-parallel to the surface.

34. A method as in claim 22 , further comprising adding one or more support materials to the nanostructures, prior to the act of removing.

35. A method as in claim 22 , wherein the nanostructure is a nanowire.

Assignees

• Massachusetts Inst Technology

Inventors

• Hart Anastasios John
• Wardle Brian L
• Garcia Enrique J
• Slocum Alexander H

Classifications

• C01B32/158

  Carbon nanotubes · CPC title

• C01B2202/08

  Aligned nanotubes · CPC title

• C01B32/16

  Preparation · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• Y10S977/742

  Carbon nanotubes, CNTs · CPC title