Magnetic production of carbon nanotubes and filaments

• US 20020192141A1
• Filed: 05/22/2001
• Published: 12/19/2002
• Est. Priority Date: 05/22/2001
• Status: Active Grant

• Current Assignee: Little, Reginald Bernard
• Original Assignee: Little, Reginald Bernard
• Inventors: Little, Reginald Bernard
• Granted Patent: US 6,761,871 B2
• Time in Patent Office: Days
• US Class Current: 423/447.1
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: D01F 9/12 Carbon filaments; Apparatus specially adapted for the manufacture thereof
• CPC Class Codes: Y10S 977/838 Magnetic property of nanomaterial
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition
• CPC Class Codes: Y10S 977/896 Chemical synthesis, e.g. chemical bonding or breaking

Abstract

A catalyzing process under intense external magnetic fields is disclosed that is useful for accelerating carbon nanotube formation. A synthetic scheme is also disclosed. The nanotubes maybe magnetically aligned during the growth and formation and pose many applications.

Claims

1. A process for production of carbon nanotubes;

said process comprises the formation of catalytic nanoparticles, the annealing and orientation of the said catalytic nanoparticles in a strong external magnetic field, and the subsequent growth and orientation of carbon nanotubes on the said catalytic nanoparticles in this strong magnetic environment.

2. A process as in claim 1, wherein the said catalytic nanoparticles are composed of any paramagnetic transition metal or any alloy thereof or any oxide thereof or any transition metal containing substance possessing ferromagnetic and paramagnetic properties.

3. A process as in claim 2, wherein the said catalytic nanoparticles are magnetically formed of any size.

4. A process as in claim 3, wherein the said catalytic nanoparticles are magnetically formed by chemical vapor deposition, physical vapor deposition, laser ablation and/or arc discharge techniques.

5. A process as in claim 4, wherein the said magnetically oriented catalytic nanoparticles are oriented with an external magnetic field of any intensity so as to magnetically enhance the formation and growth of the subsequent carbon nanotubes.

6. A process as in claim 5, wherein the said external magnetic field is exerted for any time duration:

steady, sporadic or periodic, so as to magnetically maximize subsequent carbon nanotube formation.

7. A process as in claim 6, wherein the said external magnetic field direction is stationary, sporadically varied or periodically varied, so as to magnetically maximize subsequent carbon nanotube formation.

8. A process as in claim 7, wherein the said catalytic nanoparticles growth magnetically grown at any temperature.

9. A process as in claim 8, wherein the said catalytic nanoparticles growth magnetically grown at any flow rates.

10. A process as in claim 9, wherein the said catalytic nanoparticles growth magnetically grown at any and pressures.

11. A process as in claim 10, wherein the said catalytic nanoparticles are formed using any precursors.

12. A process as in claim 11, wherein the said catalytic nanoparticle are used to magnetically form carbon nanotubes upon the said nanoparticle surface by using intense external magnetic fields.

13. A process as in claim 12, wherein the said surface includes any surface of the said nanoparticle.

14. A process as in claim 13, wherein the nanotubes are magnetically formed by chemical vapor deposition, physical vapor deposition, laser ablation and/or arc discharge techniques.

15. A process as in claim 14, wherein the said nanotubes are magnetically formed using external magnetic fields of any intensity.

16. A process as in claim 15, wherein the said nanotubes are magnetically formed using any magnetic field direction:

stationary, sporadically varying or periodically varying, so as to magnetically maximize the said nanotube formation.

17. A process as in claim 16, wherein the said nanotubes are magnetically formed using any time schedule of the intensity of the magnetic field, steady, sporadically changing or periodically changing, so as to magnetically maximize the nanotube formation.

18. A process as in claim 17, wherein the said nanotubes are magnetically formed using any precursor.

19. A process as in claim 18, wherein the said nanotubes are magnetically formed using any temperatures.

20. A process as in claim 19, wherein the said nanotubes are magnetically formed using any flow rates.

21. A process as in claim 20, wherein the said nanotubes are magnetically formed using any pressures.

22. A process as in 21, wherein multi walled nanotubes are formed.

23. A process as in 22, wherein filamentous carbon rods are formed.