Abstract: An improved catalyst for producing carbon fibrils is made by incorporating an effective yield-enhancing amount of a carboxylate into a fibril-forming catalyst. Alternatively, such a catalyst is made by coprecipitating a compound of a metal having fibril-forming catalytic properties and an aluminum and/or magnesium compound, optionally in the presence of carbon particles or carbon fibril aggregates. The catalyst may also be made by incorporating a compound of a fibril-forming metal onto magnesia particles in carbon particles or carbon fibril aggregates. The catalysts, methods of using them to form carbon fibrils and those carbon fibrils are also disclosed.
Abstract: A method of making randomly oriented carbons fibrils having a cylindrical constant diameter with c-axes perpendicular to their cylindrical axis, which are free of pyrolytically deposited carbon, with a diameter of between 3.5 and 70 nanometers, by dispersing carbon fibrils in a medium and separating them from the medium, by filtration or evaporation to form a porous mat or sheet.
Type:
Grant
Filed:
June 6, 1995
Date of Patent:
December 8, 1998
Assignee:
Hyperion Catalysis Int'l Inc.
Inventors:
Howard Tennent, Robert W. Hausslein, Nicholas Leventis, David Moy
Abstract: It has now been found that highly advantageous three-dimensional, macroscopic assemblages of randomly oriented carbon fibrils can be prepared which have relatively uniform physical properties along one, preferably two and most desirably three-dimensional axis of the three-dimensional assemblage. Preferred compositions prepared according to the methods of the invention have uniform physical properties along at least one dimensional axis and have relatively isotropic physical properties in at least one plane of the assemblage and most desirably are isotropic throughout the entire three-dimensional structure.
Type:
Grant
Filed:
April 27, 1995
Date of Patent:
November 25, 1997
Assignee:
Hyperion Catalysis Int'l., Inc.
Inventors:
Howard Tennent, Robert W. Hausslein, Nicholas Leventis, David Moy
Abstract: This invention concerns composite materials comprising a plurality of carbon fibrils in a matrix wherein the carbon fibrils are each characterized by a substantially constant diameter between about 3.5 to 70 nanometers and are substantially free of pyrolytically deposited thermal carbon.
Type:
Grant
Filed:
June 5, 1995
Date of Patent:
November 26, 1996
Assignee:
Hyperion Catalysis Int'l, Inc.
Inventors:
Howard G. Tennent, James J. Barber, Robert Hoch
Abstract: A compounding process for preparing a composite that includes introducing one or more fillers and a matrix material into a stirred ball mill and subjecting the fillers and the matrix material to a combination of shear and impact forces under reaction conditions including reaction time sufficient to reduce the size of agglomerates formed by the fillers to a value below a pre-determined value to disperse the fillers throughout the matrix material.
Abstract: The invention relates to carbon fibrils characterized by a substantially constant diameter, length greater than about 5 times the diameter, an ordered outer region of catalytically grown, multiple, substantially continuous layers of ordered carbon atoms having an outside diameter between about 3.5 and 70 nanometers, and a distinct inner core region. Each of the layers and the core are disposed substantially concentrically about the cylindrical axis of the fibril. The fibrils are substantially free of pyrolytically deposited thermal carbon with the diameter of the fibrils being equal to the outside diameter of the ordered outer region.
Type:
Grant
Filed:
October 1, 1990
Date of Patent:
November 24, 1992
Assignee:
Hyperion Catalysis Int'l., Inc.
Inventors:
Howard G. Tennent, James J. Barber, Robert Hoch