United States of America As Represented by the Secretary of the Air Force

General Atomics, Inc.

Ga Technologies, Inc.

Barry W McQuillan

George H Reynolds

John H Norman

Frederick H Elsner

Khodabakhsh S Mazdiyasni

Debra J Treacy

A method for the manufacture of superconducting polycrystalline ceramic materials by the decomposition of a mixture of isopropoxides.

Manufacture of high purity superconducting ceramic

Hollow ceramic fibers are made by intercalating carbon fibers with a metal chloride and then heating the intercalated fibers in air to oxidize or burn off the carbon, leaving metal oxide fibers having generally the size and structure of the carbon fiber precursors. The fibers are then soaked in boric acid solution, briefly dried and heated at a high temperature to make hollow alumina fibers. The temperatures at which the boric acid soaked fibers are heated can be varied to produce different tube morphologies.

Production of 10 micron diameter hollow ceramic fibers

Ceramic metal oxide fibers are made by intercalating graphitic graphite fibers with a mixture of metal chlorides and then heating the intercalated fibers to oxidize or burn off the carbon leaving a metal oxide fiber having generally the shape and structure of the graphite fiber precursors to make composite fibers, such as binary fibers of aluminum oxide-zirconium oxide and aluminum oxide-ferric oxide.

Preparation of metal oxide fibers from intercalated graphite fibers

Carbon-graphite fibers are coated with a protective metal oxide coating by intercalating the fibers with a metal chloride and then deintercalating the chlorine by hydrolysis to form a metal oxide over the fibers. An example using aluminum chloride to form an aluminum oxide coating is described.

Process for making coatings on graphite using intercalated species

Water is decomposed to molecular hydrogen and molecular oxygen in a thermochemical cycle which comprises (i) reacting Cl.sub.2, Br.sub.2 or BrCl with water to obtain oxygen and hydrogen halide; (ii) forming a graphite intercalation compound with a hydrogen halide from step (i) and a metal halide selected from MBr.sub.i Cl.sub.3-i, wherein M is aluminum, gallium or indium and i is 0, 1, 2 or 3, and thereby obtaining hydrogen; (iii) decomposing by heating the graphite intercalation compound formed in step (ii); (iv) recycling the halogen produced in step (iii) for use in step (i); and (v) recycling the metal halide and graphite produced in step (iv) for use in step (ii).

Growing community of inventors

San Diego, CA, United States of America

Barry W McQuillan