Fibers of aligned single-wall carbon nanotubes and process for making the same

• US 20030170166A1
• Filed: 07/02/2002
• Published: 09/11/2003
• Est. Priority Date: 07/06/2001
• Status: Active Grant

• Current Assignee: Dexmat Incorporated
• Original Assignee: Rice University
• Inventors: Smalley, Richard E., Sivarajan, Ramesh, Pasquali, Matteo, Hauge, Robert H., Davis, Virginia Angelica, Saini, Rajesh Kumar, Ericson, Lars Martin
• Granted Patent: US 7,125,502 B2
• Time in Patent Office: Days
• US Class Current: 423/447.1
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: D01F 11/12 with inorganic substances ; Intercalation
• CPC Class Codes: Y10S 977/842 for carbon nanotubes or fullerenes

Abstract

The present invention involves fibers of highly aligned single-wall carbon nanotubes and a process for making the same. The present invention provides a method for effectively dispersing single-wall carbon nanotubes. The process for dispersing the single-wall carbon nanotubes comprises mixing single-wall carbon nanotubes with 100% sulfuric acid or a superacid, heating and stirring under an inert, oxygen-free environment. The single-wall carbon nanotube/acid mixture is wet spun into a coagulant to form the single-wall carbon nanotube fibers. The fibers are recovered, washed and dried. The single-wall carbon nanotubes were highly aligned in the fibers, as determined by Raman spectroscopy analysis.

Claims

1. A method of making a fiber of aligned single-wall carbon nanotubes, comprising:

(a) mixing single-wall carbon nanotubes with an anhydrous acid selected from the group consisting of 100% sulfuric acid and a superacid to form a single-wall carbon nanotube/acid mixture, and

(b) spinning the single-wall carbon nanotube/acid mixture to form a fiber.

2. The method of claim 1, wherein the superacid is selected from the group consisting of a Brø

nsted superacid, a Lewis superacid, a Brø

nsted-Lewis conjugate superacid and mixtures thereof.

3. The method of claim 1, wherein the Brø

nsted superacid is selected from the group consisting of superacids include perchloric acid, chlorosulfuric acid, fluorosulfuric acid, chlorosulfonic acid, fluorosulfonic acid, perfluoroalkanesulfonic acid, trifluoromethanesulfonic acid, higher perfluoroalkanesulfonic acid, C₂F₅SO₃H, C₄F₉SO₃H, C₅F₁₁SO₃H, C₆F₁₃SO₃H, C₈F₁₇SO₃H,

4. The method of claim 1, wherein the Lewis superacid is selected from the group consisting of antimony pentafluoride, arsenic pentafluoride, tantalum pentafluoride and niobium pentafluoride.

5. The method of claim 1, wherein the Brø

nsted-Lewis conjugate superacid is selected from the group consisting of oleum, polyphosphoric acid-oleum mixtures, tetra(hydrogen sulfato)boric acid-sulfuric acid, fluorosulfuric acid-antimony pentafluoride, fluorosulfuric acid-sulfur trioxide, fluorosulfuric acid-arsenic pentafluoride, HSO₃F;

HF;

SbF₅, HSO₃F;

SbF₅;

SO₃, a perfluoroalkanesulfonic acid-based system, C_nF_2n+1SO₃H;

SbF₅, where n=1, 2 or 4, CF₃SO₃H;

B(SO₃CF₃)₃, hydrogen-fluoride-antimony pentafluoride, hydrogen fluoride-tantalum pentafluoride, hydrogen fluoride-boron trifluoride, a conjugate Friedel-Crafts acid, HBr;

AlBr₃, and HCl;

AlCl₃.

6. The method of claim 1, wherein the superacid is oleum.

7. The method of claim 1, wherein the oleum contains up to about 30% SO₃.

8. The method of claim 1, wherein the superacid is trifluoromethanesulfonic acid.

9. The method of claim 1, wherein the single-wall carbon nanotubes are at a concentration range between about 0.01 wt % and about 10 wt % in the acid.

10. The method of claim 1, wherein the single-wall carbon nanotubes are at a concentration range between about 4 wt % and about 10 wt % in the acid.

11. The method of claim 1, wherein the single-wall carbon nanotubes are at a concentration range between about 6 wt % and about 8 wt % in the acid.

12. The method of claim 1, wherein the mixing step is done in a time range between about 3 hours and about 3 days.

13. The method of claim 1, wherein the spinning step comprises wet spinning into a coagulant.

14. The method of claim 13, wherein the coagulant is selected from the group consisting of water, diethyl ether, 10% sulfuric acid, ethylene glycol and mixtures thereof.

15. The method of claim 1, wherein the aligned single-wall carbon nanotubes in the fiber have a Fraser fraction of at least about 0.25.

16. The method of claim 1, wherein the aligned single-wall carbon nanotubes in the fiber have a Fraser fraction of at least about 0.5.

17. The method of claim 1, wherein the aligned single-wall carbon nanotubes in the fiber have a Fraser fraction of at least about 0.7.

18. The method of claim 1, further comprising washing the fiber.

19. The method of claim 18, wherein the washing is done in a liquid selected from the group consisting of water, diethyl ether, methanol and combinations thereof.

20. The method of claim 1, further comprising drying the fiber.

21. The method of claim 20, wherein the drying is done by a method selected from the group consisting of heating, air drying, vacuum drying and a combination thereof.

22. The method of claim 1, further comprising annealing the fiber.

23. The method of claim 22, wherein the annealing is done at a temperature in the range between about 400°

C. and about 800°

C.

24. The method of claim 1 further comprising subjecting the fiber to a reducing environment at an elevated temperature.

25. The method of claim 24, wherein the temperature is up to about 450°

C.

26. The method of claim 1, wherein the mixing step is done under an inert atmosphere.

27. The method of claim 1, wherein the mixing step is done at a temperature range between about room temperature and about 150°

C.

28. A fiber of aligned single-wall carbon nanotubes made by the process comprising:

(a) mixing single-wall carbon nanotubes with an anhydrous acid selected from the group consisting of 100% sulfuric acid and a superacid to form a single-wall carbon nanotube/acid mixture, and

(b) spinning the single-wall carbon nanotube/acid mixture to form a fiber.

29. The fiber of claim 28, wherein the superacid is selected from the group consisting of a Brø

nsted superacid, a Lewis superacid, a Brø

nsted-Lewis conjugate superacid and mixtures thereof.

30. The fiber of claim 28, wherein the Brø

nsted superacid is selected from the group consisting of superacids include perchloric acid, chlorosulfuric acid, fluorosulfuric acid, chlorosulfonic acid, fluorosulfonic acid, perfluoroalkanesulfonic acid, trifluoromethanesulfonic acid, higher perfluoroalkanesulfonic acid, C₂F₅SO₃H, C₄F₉SO₃H, C₅F₁₁SO₃H, C₆F₁₃SO₃H, C₈F₁₇SO₃H,

31. The fiber of claim 28, wherein the Lewis superacid is selected from the group consisting of antimony pentafluoride, arsenic pentafluoride, tantalum pentafluoride and niobium pentafluoride.

32. The fiber of claim 28, wherein the Brø

nsted-Lewis conjugate superacid is selected from the group consisting of oleum, polyphosphoric acid-oleum mixtures, tetra(hydrogen sulfato)boric acid-sulfuric acid, fluorosulfuric acid-antimony pentafluoride, fluorosulfuric acid-sulfur trioxide, fluorosulfuric acid-arsenic pentafluoride, HSO₃F;

HF;

SbF₅, HSO₃F;

SbF₅;

SO₃, a perfluoroalkanesulfonic acid-based system, C_nF_2n+1SO₃H;

SbF₅, where n=1, 2 or 4, CF₃SO₃H;

B(SO₃CF₃)₃, hydrogen-fluoride-antimony pentafluoride, hydrogen fluoride-tantalum pentafluoride, hydrogen fluoride-boron trifluoride, a conjugate Friedel-Crafts acid, HBr;

AlBr₃, and HCl;

AlCl₃.

33. A fiber of aligned single-wall carbon nanotubes, wherein the aligned single-wall carbon nanotubes in the fiber have a Fraser fraction of at least about 0.25.

34. The fiber of claim 33, wherein the aligned single-wall carbon nanotubes in the fiber have a Fraser fraction of at least about 0.5.

35. The fiber of claim 33, wherein the aligned single-wall carbon nanotubes in the fiber have a Fraser fraction of at least about 0.7.

36. The fiber of claim 33, wherein the fiber is present in an article selected from the group consisting of fibers, cables, and electrical transmission lines.

37. The fiber of claim 33, wherein the fiber is present in an article selected from the group consisting of electrochemical electrodes, battery electrodes, sensors, and transducer elements.

38. The fiber of claim 33, wherein the fiber is present in an article selected from the group consisting of airframes, components for aircraft, components for missiles, vehicle bodies, bullet-proof vests, armor, and ship hulls.

39. The fiber of claim 33, wherein the fiber is present in a catalyst support.

40. The fiber of claim 33, wherein the fiber is present in an article selected from the group consisting of chemically inert materials, biologically-inert materials, materials that absorb moieties that intercalate, materials that support moieties that intercalate and materials that dispense moieties that intercalate.

41. The fiber of claim 33 wherein the fiber is present in an article selected from the group consisting of skis, surfboards, sails, racquets and other sporting goods.

42. The fiber of claim 33 wherein the fiber is present in woven material wherein the woven material is woven with other fibers selected from the group consisting of single-wall carbon nanotube fibers, natural fibers, synthetic fibers and combinations thereof.

43. The fiber of claim 33, wherein the fiber is present in an article selected from the group consisting of structural materials, impact-resistant materials, structural laminates having layers with different tube orientations, pressure vessel exteriors, and pressure vessel reinforcement, thermal management materials, and heat-resistant materials.

44. The fiber of claim 43, wherein the thermal management material is a heat-transporting material.

45. A method for forming intercalated single-wall carbon nanotubes, comprising:

mixing single-wall carbon nanotubes with an anhydrous acid selected from the group consisting of 100% sulfuric acid, an intercalating species and a superacid, under an inert atmosphere at a temperature ranging from about room temperature to about 150°

C. for a time sufficient to form a single-wall carbon nanotube/acid mixture.

46. The method of claim 45, wherein the superacid is selected from the group consisting of a Brø

nsted superacid, a Lewis superacid, a Brø

nsted-Lewis conjugate superacid and mixtures thereof.

47. The method of claim 46, wherein the Brø

nsted superacid is selected from the group consisting of superacids include perchloric acid, chlorosulfuric acid, fluorosulfuric acid, chlorosulfonic acid, fluorosulfonic acid, perfluoroalkanesulfonic acid, trifluoromethanesulfonic acid, higher perfluoroalkanesulfonic acid, C₂F₅SO₃H, C₄F₉SO₃H, C₅F₁₁SO₃H, C₆F₁₃SO₃H, C₈F₁₇SO₃H,

48. The method of claim 46, wherein the Lewis superacid is selected from the group consisting of antimony pentafluoride, arsenic pentafluoride, tantalum pentafluoride and niobium pentafluoride.

49. The method of claim 46, wherein the Brø

nsted-Lewis conjugate superacid is selected from the group consisting of oleum, polyphosphoric acid-oleum mixtures, tetra(hydrogen sulfato)boric acid-sulfuric acid, fluorosulfuric acid-antimony pentafluoride, fluorosulfuric acid-sulfur trioxide, fluorosulfuric acid-arsenic pentafluoride, HSO₃F;

HF;

SbF₅, HSO₃F;

SbF₅;

SO₃, a perfluoroalkanesulfonic acid-based system, C_nF_2n+1SO₃H;

SbF₅, where n=1, 2 or 4, CF₃SO₃H;

B(SO₃CF₃)₃, hydrogen-fluoride-antimony pentafluoride, hydrogen fluoride-tantalum pentafluoride, hydrogen fluoride-boron trifluoride, a conjugate Friedel-Crafts acid, HBr;

AlBr₃, and HCl;

AlCl₃.

50. The method of claim 45, wherein the intercalating species comprises a chemical selected from the group consisting of concentrated nitric acid, concentrated sulfuric acid, 100% sulfuric acid, oleum, mixtures of polyphosphoric acid and oleum, fluorosulfuric acid, chlorosulfuric acid, sulfonic acid, fluorosulfonic acid, chlorosulfonic acid, alkyl sulfonic acid, aromatic sulfonic acid, perchloroalkyl sulfonic acid, perchloroaromatic sulfonic acid, perfluoroalkyl sulfonic acid, perfluoroaromatic sulfonic acid, metal halide, hydrogen fluoride, chlorine, fluorine, bromine, iodine and mixtures thereof.

51. The method of claim 45, wherein the single-wall carbon nanotubes are at a concentration range between about 0.01 wt % and about 10 wt % in the acid.

52. The method of claim 45, wherein the anhydrous acid is an aggregate substantially redispersing acid.

53. The method of claim 45, wherein the intercalated single-wall carbon nanotubes form super ropes.

54. The method of claim 45, wherein the anhydrous acid is an aggregate redispersible acid.

55. The method of claim 45, wherein the intercalated single-wall carbon nanotubes form super ropes.

56. The method of claim 55, wherein the super ropes have a diameter in the range between about one-half micron and about 2 microns.

57. The method for dispersing single-wall carbon nanotubes comprising:

(a) providing intercalated single-wall carbon nanotubes, and

(b) mixing the intercalated nanotubes in a fluid material selected from the group consisting of water, surfactant, dimethyl formamide, chloroform, dichlorobenzene, molten polymer, molten ceramic and mixtures thereof.

58. A composition of aligned single-wall carbon nanotubes produced by the process comprising:

(a) mixing single-wall carbon nanotubes with an anhydrous acid selected from the group consisting of 100% sulfuric acid and a superacid to form a single-wall carbon nanotube/acid mixture; and

(b) incorporating water into the single-wall nanotube/acid mixture to form a composite comprising the aligned single-wall carbon nanotubes, wherein the aligned single-wall carbon nanotubes within the composite are substantially redispersible.

59. The composition of claim 58, wherein the aligned single-wall carbon nanotubes within the composite are redispersible.