EP0198558A2
Expired / Lapsed
EP
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Method for the preparation of carbon filaments and carbon filaments obtained by the method
Assignee: Dow Chemical Co
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Filing: 1986-04-14
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Granted: —
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Expires: 2006-04-14
Abstract
Abstract A method of preparing carbon filaments is disclosed, which comprises exposing a suitable thermostable substrate which is covered with reduced monocrystalline metal particles with a diameter of at least 5 nanometers to a carbon containing gas mixture at temperatures of about 250 °C up to about 700 to 800 °C for a period of time sufficient to form filaments of the desired length, and thereafter removing the substrate and/or the metal particles. The filaments are characterized by a crystalline graphitic structure and a morphology defined by a fishbone-like arrangement of the graphite layers along the axis of the filaments. A high carbide content is a prerequisite for the nucleation of the filamentous carbon with a fishbone like structure.
Inventors
- 👤 John Wilhelm Geus
- 👤 John Walter Linowski
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 17:13
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/127; D01F9/1278; B; B82; B82Y; B82Y30/00; D01F9/1271; D01F9/1272
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
120 words
A method for the preparation of carbon filaments, comprising the steps of exposing a thermostable support having substantially completely reduced monocrystalline metal particles to a carbon containing gas at a temperature of from about 250°C up to about 700°C to 800°C for a period of time sufficient to form carbon filaments of a desired dimension on the support, the upper temperature limits being contingent upon the stability of a metal carbide which is formed preceding the nucleation of filamentous carbon, said filaments being characterized by a crystalline graphitic structure and a morphology defined by a fishbone-like arrangement of the graphite layers along the axis of the filaments and thereafter separating the carbon filaments from the support and/or the metal particles.
Claim 2
Independent Claim
120 words
A method for the preparation of carbon filaments, comprising the steps of exposing a thermostable support having substantially completely reduced monocrystalline metal particles to a carbon containing gas at a temperature of from about 250°C up to about 700°C to 800°C for a period of time sufficient to form carbon filaments of a desired dimension on the support, the upper temperature limits being contingent upon the stability of a metal carbide which is formed preceding the nucleation of filamentous carbon, said filaments being characterized by a crystalline graphitic structure and a morphology defined by a fishbone-like arrangement of the graphite layers along the axis of the filaments and thereafter separating the carbon filaments from the support and/or the metal particles.
Claim 3
Dependent Claim
25 words
The method of Claim 1, including the step of employing monccrystalline metal particles on the support surface which are able to form unstable metal carbides.
Claim 4
Independent Claim
22 words
The method of Claims 1, wherein said metal particles are ferro magnetic and are employed to form carbon filaments on the support.
Claim 5
Dependent Claim
18 words
The method of Claim 3, wherein the ferromagnetic particles are selected from iron, cobalt, nickel, and alloys thereof.
Claim 6
Dependent Claim
21 words
The method of Claim 1, wherein the metal particles have a particle size of at least about 5 nanometers (nm). -
Claim 7
Dependent Claim
21 words
The method of Claim 1, wherein the metal - particles have a particle size of at least about 10 nanometer (nm).
Claim 8
Dependent Claim
25 words
The method of Claim 5 or 6, wherein the size of the metal particles is adjustable to control the desired diameter of the carbon filaments.
Claim 9
Dependent Claim
31 words
The method of Claim 1, wherein loading of the support surface with metal particles is adjusted to control the desired number of the carbon filaments per unit area of support surface.
Claim 10
Dependent Claim
30 words
The method of Claim 3, wherein said ferromagnetic particles are located at the end of the carbon filaments, and subjecting said filaments and particles to an electric and/or magnetic field.
Claim 11
Dependent Claim
53 words
The method of Claim 1, wherein, after completion of longitudinal growth of the carbon filaments, they are subjected to a controlled amount of a carbon-containing gas at a temperature at which the fibers no longer grow in said longitudinal direction, said temperature being in the range of from about 900° to about 1100°C.
Claim 12
Dependent Claim
41 words
The method of Claim 1 or 10, wherein the carbon filaments are subjected to a temperature of from about 1100° to about 1800°C, in the absence of a carbon-containing gas, to effect a re-orientation of the crystals in the carbon filaments.
Claim 13
Dependent Claim
21 words
The method of Claim 1, wherein a bundle of parallel carbon filaments is grown on the support covered by metal particles.
Claim 14
Dependent Claim
28 words
The method of Claim 1, wherein said. support is selected from non-metallic materials, metals, not forming bulk carbides metal alloys, metal oxides, metal carbides, metal sulfides, and carbon.
Claim 15
Dependent Claim
43 words
The method of Claim 13, wherein said non-metallic materials are selected from silica, alumina, and other inert support materials, with the proviso that said materials exhibit desirable metal particle -support interactions to promote the formation of carbon filaments from the supported metal particles.
Claim 16
Dependent Claim
13 words
Carbon filaments produced by the method of Claims 1, 9, 10 or 11.
Claim 17
Independent Claim
34 words
A method for the preparation of reinforced polymers, wherein the carbon filaments of Claims 1, 10 or 11 are impregnated with a molten polymer, a monomer, or a mixture thereof, that is subsequently polymerized.
Claim 18
Dependent Claim
50 words
A method for the preparation of a reinforced polymer, wherein after impregnation with a molten polymer or not yet polymerized monomer, or mixtures thereof, the carbon filaments of Claim 1, 10 or 11 are dispersed in the molten mass and the suspension thus obtained is subjected to a shear force.
Claim 19
Dependent Claim
53 words
A method for the preparation of a reinforced polymer, wherein the carbon filaments of Claim 9 with ferro magnetic particles at the end of the filaments are dispersed in a molten polymer or monomer, or mixtures thereof, after which the suspension is subjected to an applied external electric and/or magnetic field during solidification.
Claim 20
Dependent Claim
12 words
Reinforced polymers produced by the method of Claims 16, 17 or 18.
Claim 21
Dependent Claim
57 words
A method for the production of an electrode wherein after the formation of the filaments of Claim 1, the temperature is raised to above about 900 0 C, while maintaining the atmosphere of the carbon containing gas mixture to enhance the growth of carbon deposits on the filaments to form a dense and homogeneous block of carbon.
Claim 22
Dependent Claim
10 words
A carbon electrode, obtained by the method of Claim 20.
References Cited (Backward Citations)
No citation records indexed.
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