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US 4,663,230 AGranted
Carbon fibrils, method for producing same and compositions containing same
AssigneeHyperion Catalysis International, Inc.
InventorHoward G. Tennent
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AssigneeHyperion Catalysis International, Inc.
InventorHoward G. Tennent
Estimating the term…
This invention concerns an essentially cylindrical discrete carbon fibril characterized by a substantially constant diameter between about 3.5 and about 70 nanometers, e.g. between about 7 and 25 nanometers, length greater than about 10.sup.2 times the diameter, an outer region of multiple essentially continuous layers of ordered carbon atoms and a distinct inner core region, each of the layers and core disposed substantially concentrically about the cylindrical axis of the fibril. Preferably the entire fibril is substantially free of thermal carbon overcoat. The invention further concerns a plurality of such fibrils. The fibril or plurality of fibrils of this invention may be produced by contacting for an appropriate period of time and at suitable pressure a suitable metal-containing particle with a suitable gaseous, carbon-containing compound, at a temperature between about 850.degree. C. and 1200.degree. C., the ratio on a dry weight basis of carbon-containing compound to metal containing particle being at least about 100:1. The fibrils are useful in composites having a matrix of e.g., an organic polymer, an inorganic polymer or a metal. In one embodiment the fibrils are incorporated into structural materials in a method of reinforcement. In other embodiments the fibrils may be used to enhance the electrical or thermal conductivity of a material, to increase the surface area of an electrode or capacitor plate, to provide a support for a catalyst, or to shield an object from electromagnetic radiation.
An essentially cylindrical discrete carbon fibril characterized -by a substantially constant diameter between -about 3.5 and about 70 nanometers, length greater than -about 10.sup.2 times the diameter, an outer region of multiple -essentially continuous layers of ordered carbon atoms and -a distinct inner core region, each of the layers and core -disposed substantially concentrically about the cylindrical -axis of the fibril. -
A plurality of essentially discrete carbon fibrils -characterized by a substantially constant diameter between -about 3.5 and about 70 nanometers, length greater than - about 10.sup.2 times the diameter, an outer region of multiple -essentially continuous layers of ordered carbon atoms and -a distinct inner core region, each of the layers and core -disposed substantially concentrically about the cylindrical -axis of the fibrils. -
A method for producing an essentially cylindrical, -carbon fibril which comprises contacting for an appropriate -period of time and at a suitable pressure a suitable -metal-containing -particle with a suitable gaseous, carbon-containing -compound, at a temperature between about 850.degree. C. -and about 1200.degree. C., the ratio on a dry weight basis of -carbon-containing compound to metal-containing particle -being at least about 100:1. -
A method for producing an essentially cylindrical -carbon fibril which comprises contacting for a period of -time from about 10 seconds to about 180 minutes and at a -pressure of from about one-tenth atmosphere to about ten -atmospheres a suitable iron-containing particle with gaseous -benzene at a temperature between about 900.degree. C. and about -1150.degree. C., the ratio on a dry weight basis of benzene to -iron-containing particle being at least about 1000:1. -
A method for producing an essentially cylindrical -carbon fibril which comprises contacting for an appropriate -period of time and at a suitable pressure a suitable -metal-containing particle with a suitable gaseous, carbon-containing compound, wherein the metal-containing -particle is independently heated to a temperature between -about 850.degree. C. and about 1800.degree. C., the temperature of the -particle being higher than the temperature of the gaseous, -carbon-containing compound. -
A method for producing a substantially uniform plurality - of essentially cylindrical, discrete carbon fibrils -which comprises contacting for an appropriate period of -time and at a suitable pressure, suitable metal-containing -particles with a suitable gaseous carbon-containing compound, at a temperature between about 850.degree. C. and 1200.degree. C., the -ratio on a dry weight basis of carbon-containing compound -to metal-containing particles being at least about 100:1. -
Dependencies are inferred from the claim text.