Hyperion Catalysis International, Inc.

Chun-Ming Niu

David Moy

Howard G Tennent

Alan B Fischer

Robert Hoch

Naoya Ogata

A plurality of carbide, such as silicon carbide, tungsten carbide, etc., nanofibrils predominantly having diameters substantially less than about 100 nm and a method for making such carbide nanofibrils. The method includes the steps of: heating a plurality of carbon nanotubes or nanofibrils predominantly having diameters less than about 50 nm in a reaction chamber in the presence of a gas of the form QA, where Q is a metal capable of forming a carbide, A is an element or radical and n and m are integers necessary to satisfy valences, such as, for example silicon monoxide, and an inert gas in a reaction vessel to a temperature substantially less than 1700 C but sufficently high to cause substantial reaction of the metal in the gas with the carbon of said carbon nanotubes or nanofibrils to form, in situ, solid carbide nanofibrils, the temperature being sufficiently low to prevent substantial fusing together of individidual ones of said carbide nanofibrils, removing at least a portion of A-based gas from said reaction chamber as said reaction progresses, and maintaining said temperature until substantially all the carbon of said nanotubes or nanofibrils has been converted into Q-based carbide.

Carbide nanofibrils and method of making same

Graphitic nanotubes, which includes tubular fullerenes (commonly called 'buckytubes') and fibrils, which are functionalized by chemical substitution or by adsorption of functional moieties. More specifically the invention relates to graphitic nanotubes which are uniformly or non-uniformly substituted with chemical moieties or upon which certain cyclic compounds are adsorbed and to complex structures comprised of such functionalized fibrils linked to one another. The invention also relates to methods of introducing functional groups onto the surface of such fibrils.

Functionalized nanotubes

This invention relates to rigid porous carbon structures and to methods of making same. The rigid porous structures have a high surface area which are substantially free of micropores. Methods for improving the rigidity of the carbon structures include causing the nanofibers to form bonds or become glued with other nanofibers at the fiber intersections. The bonding can be induced by chemical modification of the surface of the nanofibers to promote bonding, by adding 'gluing' agents and/or by pyrolyzing the nanofibers to cause fusion or bonding at the interconnect points.

Rigid porous carbon structures, methods of making, methods of using and products containing same

Graphitic nanofibers, which include tubular fullerenes (commonly called &ldquo;buckytubes&rdquo;), nanotubes and fibrils, which are functionalized by chemical substitution, are used as electrodes in electrochemical capacitors. The graphitic nanofiber based electrode increases the performance of the electrochemical capacitors.

Graphitic nanofibers in electrochemical capacitors

Composite electrodes including carbon nanofibers (fibrils) and an electrochemically active material are provided for use in electrochemical capacitors. The fibril composite electrodes exhibit high conductivity, improved efficiency of active materials, high stability, easy processing, and increase the performance of the capacitor. A method for producing the composite electrodes for use in electrochemical capacitors is also provided.

Fibril composite electrode for electrochemical capacitors

This invention relates to rigid porous carbon structures and to methods of making same. The rigid porous structures have a high surface area which are substantially free of micropores. Methods for improving the rigidity of the carbon structures include causing the nanofibers to form bonds or become glued with other nanofibers at the fiber intersections. The bonding can be induced by chemical modification of the surface of the nanofibers to promote bonding, by adding &ldquo;gluing&rdquo; agents and/or by pyrolyzing the nanofibeirs to cause fusion or bonding at the interconnect points.

Electrochemical capacitors having electrodes with diverse redox potentials

A high surface area carbon nanofiber is provided. The carbon nanofiber has an outer surface on which a porous high surface area layer is formed. A method of making the high surface area carbon nanofiber includes pyrolizing a polymeric coating substance provided on the outer surface of the carbon nanofiber at a temperature below the temperature at which the polymeric coating substance melts. The polymeric coating substance used as the high surface area around the carbon nanofiber may include phenolics-formaldehyde, polyacrylonitrile, styrene, divinyl benzene, cellulosic polymers and cyclotrimerized diethynyl benzene. The high surface area polymer which covers the carbon nanofiber may be functionalized with one or more functional groups.

High surface area nanofibers, methods of making, methods of using and

Rigid porous carbon structures, methods of making, methods of using and

Graphitic nanofibers, which include tubular fullerenes (commonly called 'buckytubes'), nanotubes and fibrils, which are functionalized by chemical substitution, are used as electrodes in electrochemical capacitors. The graphitic nanofiber based electrode increases the performance of the electrochemical capacitors. Preferred nanofibers have a surface area greater than about 200 m.sup.2 /gm and are substantially free of micropores.

Silicon nitride nanowhiskers predominantly having diameters substantially less than about 200 nm are disclosed. The nanowhiskers of Si.sub.3 N.sub.4 are produced by reacting gaseous SiO and N.sub.2 at elevated temperature and pressure in a reaction zone in the presence of a plurality of disperse carbon nanotubes having a diameter of from 3.5 to 70 nm.

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Somerville, MA, United States of America

Chun-Ming Niu