Continuous boron nitride nanotube yarns and methods of production

Patent metadata

Field	Value
Publication number	US-11866376-B2
Application number	US-201916666580-A
Country	US
Kind code	B2
Filing date	Oct 29, 2019
Priority date	Jul 30, 2013
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A method and apparatus for producing boron nitride nanotubes and continuous boron nitride nanotube yarn or tapes is provided. The apparatus includes rotating reaction tubes that allow for continuous chemical vapor deposition of boron nitride nanotubes. The rotation of the reaction tubes allows the boron nitride nanotubes to be spun into yarns or made into tapes, without post process or external rotation or spinning of the gathered nanotubes. Boron nitride nanotube yarns or tapes of great length can be produced as a result, thereby providing industry with a readily useable format for this type of material. Dopants such as carbon can be added to engineer the band gap of the nanotubes. Catalysts may be formed outside or inside the reactor.

First claim

What is claimed is:

1. A method of producing boron-nitride nanotube continuous yarn, the method comprising:
feeding a boron containing gas species and a nitrogen containing gas species, the nitrogen containing gas species and the boron containing gas species being the same or different, a carrier gas, and a catalyst or a catalyst precursor into a plurality of reaction tubes, each reaction tube having a first portion at a first temperature and a second portion at a second temperature greater than the first temperature;
rotating the reaction tubes around a common axis while the boron, nitrogen and catalyst flow from the first portion to the second portion of each of the plurality of reaction tubes;
growing boron-nitride nanotubes towards an end of each of the plurality of reaction tubes; and
combining the boron-nitride nanotubes into a yarn as the nanotubes exit the reaction tubes.

2. The method of claim 1 further comprising growing boron nitride nanotubes in a furnace reactor downstream of the end of the rotating reaction tubes.

3. The method of claim 1 wherein the boron containing gas species and the nitrogen containing gas species are within the same compound or complex.

4. The method of claim 1 wherein the boron containing gas species and the nitrogen containing gas species are different compounds or species.

5. The method of claim 1 wherein the nitrogen containing gas species is selected from pure nitrogen, ammonia, BH 2 NH 3 , NaNH 4 and NH 4 Cl.

6. The method of claim 1 wherein the boron containing gas species is selected from B 2 H 6 , BH 2 NH 3 , BN, B 2 O 2 , NaNH 4 , or H 3 BO3, B 3 N 3 H 6 and B 10 H 14 .

7. The method of claim 3 wherein the boron and nitrogen containing gas species is selected from at least one of h-BN, c-BN, BH 2 NH 3 , BN, BNH 6 , dimethylamine borane ((CH 3 ) 2 NH·BH 3 ), the boron ammoniate complex (H 3 BNH 3 ) and borazine (BH) 3 (NH) 3 .

8. The method of claim 1 wherein a catalyst precursor comprises an organo-metallic compound, a sulfur containing organic compound, or both.

9. The method of claim 1 wherein a first catalyst precursor comprises iron penta-carbonyl or ferrocene and a second catalyst precursor or a catalyst aid precursor comprises thiophene.

10. The method of claim 1 wherein the catalyst is formed inside the reaction tubes.

11. The method of claim 1 wherein the catalyst is formed outside of the reaction tubes.

12. The method of claim 11 wherein the catalyst is introduced to the reactions tubes as a particle.

13. The method of claim 11 wherein the method includes combining a catalyst precursor with a reducing agent.

14. The method of claim 13 wherein the reducing agent is selected from at least one of sodium borohydride, dimethylamine borane, hydrazine or sodium hypophosphate.

15. The method of claim 11 wherein the catalyst is essentially free of carbon.

16. The method of claim 13 wherein the catalyst precursor is combined with a reducing agent at a temperature below 25° C.

17. The method of claim 11 wherein the catalyst is a metallic particle having an average size of less than or equal to 30 nm.

18. The method of claim 1 comprising:
gathering boron nitride nanotubes exiting the reaction tubes;
holding the gathered boron nitride nanotubes together; and
allowing the reaction tubes to spin the boron nitride nanotubes into a yarn.

19. The method of claim 1 comprising adding a dopant to the carrier gas.

20. The method of claim 1 wherein at least one of the boron containing gas species, the nitrogen containing gas species and the catalyst precursor is sublimed to reach the vapor phase.

Assignees

• Univ New Hampshire

Inventors

• Lashmore David S
• Bennett Tyler

Classifications

• C04B35/80 Primary

  Fibres, filaments, whiskers, platelets, or the like · CPC title

• C01B21/0641

  Preparation by direct nitridation of elemental boron · CPC title

• C01B21/0646

  Preparation by pyrolysis of boron and nitrogen containing compounds · CPC title

• C01B21/0648

  After-treatment, e.g. grinding, purification (transformation of hexagonal into cubic or wurtzitic boron nitride C04B35/5831) · CPC title

• C04B35/5831

  based on cubic boron nitrides {or Wurtzitic boron nitrides, including crystal structure transformation of powder} · CPC title