Method of forming carbon fibers

• US 6,890,506 B1
• Filed: 04/12/2002
• Issued: 05/10/2005
• Est. Priority Date: 04/12/2001
• Status: Expired due to Fees

• Current Assignee: Penn State Research Foundation
• Original Assignee: Penn State Research Foundation
• Inventors: Harutyunyan, Avetik, Pradhan, Bhabendra K., Eklund, Peter C.
• Primary Examiner(s): Hendrickson, Stuart L.
• Assistant Examiner(s): Lish, Peter J
• Application Number:
  US10/120,828
• Time in Patent Office: 1,124 Days
• Field of Search: 423/447.1, 423/447.2, 423/447.3, 423/445.R
• US Class Current: 423/447.3
• CPC Class Codes: D01F 9/12 Carbon filaments; Apparatus specially adapted for the manufacture thereof

Abstract

Carbon fiber/tubes are prepared by pyrolyzing a catalyst system that contains one or more diluents to facilitate control of the diameter of the formed carbon fiber/tube.

Claims

1. A method of forming a carbon fiber/tube, the method comprising:

providing a metalorganic, which contains a metal and a source of carbon for incorporation into a carbon fiber/tube upon pyrolysis;

combining a diluent with the metalorganic to form a diluted metalorganic, wherein the diluent comprises phthalocyanine or a derivative thereof; and

pyrolyzing the diluted metalorganic to form the carbon fiber/tube.

2. The method according to claim 1, wherein the metalorganic is subjected to a purification step prior to being combined with the diluent.

3. The method according to claim 1, comprising isolating the formed carbon fiber/tube.

4. The method according to claim 1, wherein the metal comprises iron, nickel or cobalt.

5. The method according to claim 1, comprising pyrolyzing the diluted metalorganic at a temperature from about 100°

C. to about 1000°

C.

6. The method according to claim 1, comprising forming a carbon fiber/tube having a cross-section of less than one micron.

7. The method according to claim 1 further comprising:

controlling the diameter of the carbon fiber/tube by adjusting the amount of diluent added to the metalorganic.

8. The method according to claim 7, comprising reducing the diameter of the formed carbon fiber/tube by increasing the amount of diluent.

9. The method according to claim 7, comprising isolating the formed carbon fiber/tube.

10. The method according to claim 7, comprising pyrolyzing the diluted metalorganic at a temperature from about 100°

C. to about 1000°

C.

11. The method according to claim 7, wherein the formed carbon fiber/tube has a cross-section of less than one micron.

12. A method of controlling the diameter of a carbon fiber/tube, the method comprising:

diluting a catalyst of formula (M₁Pc) with a diluent comprising phthalocyanine or a derivative thereof, where M₁ is a metal and Pc is a phthalocyanine or a derivative thereof; and

pyrolyzing the diluted catalyst to form a carbon fiber/tube with a diameter corresponding to the concentration of the metal in the diluted catalyst.

13. The method according to claim 12, comprising diluting the catalyst by adding a non-metal diluent.

14. The method according to claim 12, comprising diluting the catalyst with a non-catalytic metal diluent.

15. The method according to claim 12, wherein M₁ is nickel, iron, or cobalt.

16. The method according to claim 15, comprising diluting the nickel, iron or cobalt based catalyst by adding a metal free phthalocyanine to the metal catalyst.

17. The method according to claim 12, comprising purifying the diluted catalyst prior to pyrolysis.

18. The method according to claim 12, comprising separating the formed carbon fiber/tube from the catalyst.

19. The method according to claim 12, comprising pyrolyzing the diluted catalyst at a temperature from about 100°

C. to about 1000°

C.

20. The method according to claim 12, comprising forming a carbon fiber/tube having a cross-section of less than one micron.