Claims
- 1. A method of preparing a three-dimensional, macroscopic assemblage of a multiplicity of randomly oriented carbon fibrils, said fibrils being substantially cylindrical with a substantially constant diameter, having c-axes substantially perpendicular to their cylindrical axis, being substantially free of pyrolytically deposited carbon and having a diameter between about 3.5 and 70 nanometers, said assemblage having a bulk density of from 0.001 to 0.50 gm/cc, comprising the steps of:
- (a) dispersing a multiplicity of said fibrils in a medium; and
- (b) separating said assemblage from said medium.
- 2. A method as recited in claim 1 for the formation of a porous mat or sheet of said carbon fibrils, said mat or sheet having a bulk density of from 0.05 to 0.50 gm/cc comprising the steps of:
- (a) vigorously dispersing a multiplicity of said fibrils in water or an organic solvent and thereby forming a dispersion, said dispersion containing less than 10.0 percent by weight of fibrils, and (b) filtering the dispersion to form said
- porous mat or sheet.
- 3. A method as recited in claim 2, wherein said mat or sheet has a thickness between about 0.02 and about 0.50 millimeters.
- 4. A method as recited in claim 1 for the formation of a porous mat or sheet of said carbon fibrils, said mat or sheet having a bulk density of from 0.05 to 0.50 gm/cc comprising the steps of:
- (a) vigorously dispersing a multiplicity of said fibrils in water or an organic solvent and thereby forming a dispersion, said dispersion containing less than 10.0 percent by weight of fibrils; and
- (b) permitting the water or organic solvent to evaporate from said dispersion thereby leaving said porous mat or sheet.
- 5. A method as recited in claim 4, wherein said mat or sheet has a thickness between about 0.02 and about 0.50 millimeters.
- 6. A method as recited in claim 1 for the formation of a low-density porous plug of said carbon fibrils, said plug having a bulk density of from 0.001 to 0.05 gm/cc comprising the steps of:
- (a) forming a gel or paste comprising a multiplicity of carbon fibrils in a fluid, said gel or paste comprising less than 10.0 percent by weight of fibrils;
- (b) heating said gel or paste in a pressure vessel to a temperature above the critical temperature of said fluid;
- (c) removing supercritical fluid from said pressure vessel; and
- (d) removing said porous plug from said pressure vessel.
- 7. A three-dimensional, macroscopic assemblage of randomly oriented carbon fibrils prepared by a method of claim 1.
- 8. A method as recited in claim 1, wherein the step of dispersing forms a dispersion containing from about 0.01 to about 10% fibrils in said medium.
- 9. A method as recited in claim 1, further comprising dispersing non-fibril particulate solids in said medium.
- 10. A method as recited in claim 9, wherein said particulate solids are selected from the group consisting of from MnO.sub.2 and Al.sub.2 O.sub.3.
- 11. The method as recited in claim 9, wherein said particulate solids are added up to about 50 parts particulate solids per part of fibrils.
- 12. The method as recited in claim 9, wherein said particulate solid is an electroactive material.
- 13. The method as recited in claim 9, wherein said solid particulate is a catalytically active material.
- 14. The method as recited in claim 9, wherein solid particulate is lead or a lead compound or manganese or a manganese compound.
- 15. The method as recited in claim 1, further comprising the step of incorporating a mesh on or in the assemblage during formation.
- 16. The method as recited in claim 1, wherein the step of dispersing said fibrils comprises ultrasonication.
- 17. A method of preparing a composite of (a) a three-dimensional, macroscopic assemblage of a multiplicity of randomly oriented carbon fibrils, said fibrils being substantially cylindrical with a substantially constant diameter, having c-axes substantially perpendicular to their cylindrical axis, being substantially free of pyrolytically deposited carbon and having a diameter between about 3.5 and 70 nanometers, said assemblage having a bulk density of from 0.001 to 0.50 gm/cc, and (b) a second material, comprising the steps of:
- (a) dispersing a multiplicity of said fibrils and a second material in a medium; and
- (b) separating said composite from said medium.
- 18. A composite prepared by a method of claim 17.
- 19. A method of preparing a three-dimensional, macroscopic assemblage of a multiplicity of randomly oriented carbon fibrils, said fibrils being substantially cylindrical with a substantially constant diameter, having c-axes less than substantially perpendicular to their cylindrical axis, being substantially free of pyrolytically deposited carbon and having a diameter between about 3.5 and 70 nanometers, said assemblage having a bulk density of from 0.001 to 0.50 gm/cc, comprising the steps of:
- (a) dispersing a multiplicity of said fibrils in a medium; and
- (b) separating said assemblage from said medium.
- 20. A method of preparing a three-dimensional, macroscopic assemblage of a multiplicity of randomly oriented carbon fibrils, said fibrils being substantially free of pyrolytically deposited carbon, said assemblage having a bulk density of from 0.001 to 0.50 gm/cc comprising the steps of:
- (a) dispersing a multiplicity of said fibrils in a medium; and
- (b) separating said assemblage from said medium.
Parent Case Info
This application is a division of application Ser. No. 08/428,496 (Docket No. 370077-3130), filed Apr. 27, 1995, which is a continuation of application Ser. No. 08/057,328, filed May 5, 1993 now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (5)
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0142313 |
Jun 1980 |
DEX |
WO 8603455 |
Jun 1986 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
428496 |
Apr 1995 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
57328 |
May 1993 |
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