Alkyne-assisted nanostructure growth

Patent metadata

Field	Value
Publication number	US-9394174-B2
Application number	US-201313975745-A
Country	US
Kind code	B2
Filing date	Aug 26, 2013
Priority date	Jun 17, 2009
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

The present invention relates to the formation and processing of nanostructures including nanotubes. Some embodiments provide processes for nanostructure growth using relatively mild conditions (e.g., low temperatures). In some cases, methods of the invention may improve the efficiency (e.g., catalyst efficiency) of nanostructure formation and may reduce the production of undesired byproducts during nanostructure formation, including volatile organic compounds and/or polycylic aromatic hydrocarbons. Such methods can both reduce the costs associated with nanostructure formation, as well as reduce the harmful effects of nanostructure fabrication on environmental and public health and safety.

First claim

What is claimed:

1. A method for forming carbon nanostructures, comprising:
providing a reactant vapor having a temperature of less than 300° C.;
maintaining the reactant vapor at a temperature of less than 300° C.; and
contacting the reactant vapor with a catalyst material to cause formation of nanostructures,
wherein the reactant vapor comprises an alkyne and an alkene,
wherein the catalyst material is positioned within a reaction chamber having a temperature of less than 70° C.

2. A method as in claim 1 , wherein the alkyne is ethyne, propyne, but-1-en-3-yne, or 1,3-butadiyne.

3. A method as in claim 1 , wherein the reactant vapor comprises ethylene, hydrogen, and an alkyne.

4. A method as in claim 1 , wherein the reactant vapor comprises, by volume, 16% to 35% ethylene, 16% to 70% hydrogen, and 0.1% or less alkyne, such that the total amount of ethylene, hydrogen, and alkyne equals 100%.

5. A method as in claim 1 , wherein the reactant vapor comprises, by volume, 20% ethylene, 51% hydrogen, and 29% helium.

6. A method as in claim 1 , wherein the reactant gas is substantially free of an oxygen-containing species, provided that the oxygen-containing species is not water.

7. A method as in claim 1 , wherein the act of contacting causes formation of a product vapor comprising at least one carbon-containing byproduct.

8. A method as in claim 1 , wherein the reactant vapor is maintained at a temperature of less than 100° C. prior to contacting the catalyst material.

9. A method as in claim 1 , wherein the reactant vapor is maintained at a temperature of less than 50° C. prior to contacting the catalyst material.

10. A method as in claim 1 , wherein the reactant vapor is maintained at a temperature of less than 25° C. prior to contacting the catalyst material.

11. A method as in claim 1 , wherein the nanostructures are formed on a surface of the catalyst material.

12. A method as in claim 1 , wherein the nanostructures are single-walled carbon nanotubes or multi-walled carbon nanotubes.

13. A method as in claim 1 , wherein the nanostructures are vertically aligned multi-walled carbon nanotubes.

14. A method as in claim 1 , wherein the catalyst material comprises iron.

15. A method as in claim 1 , wherein the act of contacting causes formation of a product vapor comprising at least one volatile organic compound (VOC) or polycyclic aromatic hydrocarbon (PAH).

16. A method as in claim 15 , wherein the volatile organic compound is methane, ethane, propane, propene, 1,2-butadiene, 1,3-butadiene, 1,3-butadiyne, pentane, pentene, cyclopentadiene, hexene, or benzene.

17. A method as in claim 15 , wherein the polycyclic aromatic hydrocarbon is naphthalene, acenaphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, coronene, triphenylene, naphthacene, phenanthrelene, picene, fluorene, perylene, or benzopyrene.

18. A method as in claim 16 , wherein the product vapor comprises methane in an amount less than 0.4% of the total volume of product vapor that exits the reaction chamber during formation of the nanostructure, and wherein methane is substantially not present in the reactant vapor.

19. A method as in claim 16 , wherein the product vapor comprises 1,3-butadiene in an amount less than 0.4% of the total volume of product vapor that exits the reaction chamber during formation of the nanostructure, and wherein 1,3-butadiene is substantially not present in the reactant vapor.

20. A method as in claim 17 , wherein the product vapor comprises benzene in an amount less than 0.3% of the total volume of product vapor that exits the reaction chamber during formation of the nanostructure, and wherein benzene is substantially not present in the reactant vapor.

21. A method as in claim 1 , wherein the nanostructures are formed at a growth rate of at least 1 micron per second.

22. A method as in claim 1 , wherein the nanostructures are formed with a catalyst efficiency of about 1×10 2 grams of nanostructure/grams of catalyst material or greater.

Assignees

• Massachusetts Inst Technology
• Woods Hole Oceanographic Inst
• Univ Michigan

Inventors

• Plata Desiree L
• Gschwend Philip M
• Hart Anastasios John
• Meshot Eric R
• Reddy Christopher M

Classifications

• C01B31/0293

  Chemistry & Metallurgy · mapped topic

• B82Y30/00

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

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01B31/0226 Primary

  Chemistry & Metallurgy · mapped topic

• C01B32/18

  Nanoonions; Nanoscrolls; Nanohorns; Nanocones; Nanowalls · CPC title