Westinghouse Electric Corporation

Ppg Industries, Inc.

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

The United States of America As Represented by the United States

Basf Corporation

Ppg Industries Ohio, Inc.

Bulent E Yoldas

Deborah P Partlow

Chia-Cheng Lin

Michael O Okoroafor

Clarence A Andersson

Douglas M Mattox

Deborah M Paruso

Alan E Wang

John D Feichtner

Eugene G Vaerewyck

Raymond J Bratton

Raymond W Buckman

Donald E Thomas

Ronald W Chickering

Isabel K Lloyd

Shih-Ming Ho

Bruce H Neuman

Richard B Grekila

Arthur M Filippi

Lubomyra A Yoldas

Polyurethane foams prepared using polysiloxane/polyoxyalkylene surfactants, preferably blended with a viscosity modifying agent, particularly in combination with particulate silica, especially silica aerogel, exhibit improved thermal insulating capacity, as measured by K-factor, and improved closed cell content, without increasing the density of the polyurethane foam.

Surfactants for incorporating silica aerogel in polyurethane foams

Liquid comprising from 93 to 100 percent by weight alcohol is removed from silica alcogel at subcritical temperature to produce silica aerogel. The silica aerogel produced by the method of the present invention not only has high porosity, but in most instances it also has a narrow distribution of small pore sizes. The silica aerogel is preferably reduced in size so as to form particulate silica aerogel.

Method for producing silica aerogel under subcritical conditions

Silica aerogel produced under subcritical conditions

A composite material having a fiber system embedded in a host matrix material. The fiber system has a protective reaction barrier around the embedded fibers to prevent deleterious chemical or mechanical reaction between the fiber and matrix. The fiber coating is applied by immersion of the fiber system into an alkoxide solution of the desired oxide precursor with controlled immersion and withdrawal rates with subsequent drying, heating to convert to a pure oxide state, and where required, post processing, to convert the oxide coating to a carbide or nitride, for example.

Fiber-reinforced metal or ceramic matrices

A porous body consisting of a felted fibrous skeleton covered with and bonded together by a ceramic material is provided. Also provided are methods for making such a porous body which comprise the use of ceramic polymer solutions.

Porous ceramic bodies

A method is disclosed for making an organoalkoxysilane/metal oxide sol-gel composition in an essentially aqueous medium by partially hydrolyzing an organoalkoxysilane with a limited amount of water which is essentially completely consumed in the hydrolysis reaction, adding a metal alkoxide of titanium or zirconium to the essentially anhydrous partially hydrolyzed organoalkoxysilane, completely reacting the metal alkoxide with the partially hydrolyzed organoalkoxysilane to form an oxide network and then completely hydrolyzing the composition in water.

Aqueous organoalkoxysilane/metal oxide sol-gel compositions

Disclosed is a method of encapsulating soluble or colloid solids in .alpha.-alumina by forming a solution or colloid of the solids in a liquid which has a surface tension low enough to wet a non-particulate transition alumina which has a porosity of at least 40%. The solution or colloid is permitted to impregnate the pores of the alumina and the liquid is evaporated. The alumina is then heated to its .alpha.-Al.sub.2 O.sub.3 transformation temperature to entrap waste in its matrix and seal the pores. After the alumina has cooled, the surface of the alumina can be washed to remove any solids which were not trapped in the pores.

Encapsulation of solids in alpha-alumina

An organoalkoxysilane/metal oxide sol-gel composition and method for its production are disclosed whereby an organoalkoxysilane of the general formula

Abrasion-resistant organosiloxane/metal oxide coating

A multi-component organoalkoxysilane/metal alkoxide sol-gel composition and method for its production are disclosed whereby an organoalkoxysilane of the general formula

Multi-component sol-gel protective coating composition

A method for preparing mullite (3Al.sub.2 O.sub.3.2SiO.sub.2) by partially hydrolyzing a dilute silicon alkoxide solution, combining an aluminum alkoxide with the partially hydrolyzed silicon alkoxide, eliminating terminal alkoxide groups and firing the material to about 985.degree. C.

Low temperature formation of mullite using silicon alkoxide and aluminum

The absorption of neutrons of a nuclear reactor without producing fissions is reduced by providing selected isotopes of zirconium for fabrication of parts such as cladding, thimble tubes and grids. Specifically, the zirconium is enriched in .sup.90 Zr or is depleted in .sup.91 Zr. The selected isotopes are produced by irradiating Zr(OC.sub.4 H.sub.9).sub.4.sup.t, Zr(OC.sub.5 H.sub.11).sub.4.sup.t and/or Zr(OC.sub.3 H.sub.7).sub.4.sup.t, with radiation from a CO.sub.2 laser tuned to the vibrations of the CO(.sup.90 Zr) bond or the O(.sup.91 Zr) bond.

Separation of isotopes of zirconium

Antireflective silica coating for vitreous material is substantially non-reflecting over a wide band of radiations. This is achieved by providing the coating with a graded degree of porosity which grades the index of refraction between that of air and the vitreous material of the substrate. To prepare the coating, there is first prepared a silicon-alkoxide-based coating solution of particular polymer structure produced by a controlled proportion of water to alkoxide and a controlled concentration of alkoxide to solution, along with a small amount of catalyst. The primary solvent is alcohol and the solution is polymerized and hydrolized under controlled conditions prior to use. The prepared solution is applied as a film to the vitreous substrate and rapidly dried. It is thereafter heated under controlled conditions to volatilize the hydroxyl radicals and organics therefrom and then to produce a suitable pore morphology in the residual porous silica layer. The silica layer is then etched in order to enlarge the pores in a graded fashion, with the largest of the pores remaining being sufficiently small that radiations to be passed through the substrate are not significantly scattered. For use with quartz substrates, extremely durable coatings which display only 0.1% reflectivity have been prepared.

Antireflective graded index silica coating, method for making

Disclosed is a nasicon compound and a method of making it. The nasicon compound is rhombohedral at room temperature and has the general formula

Rhombohedral nasicon compound and battery

The invention comprises a method for coupling an optical fiber to an optical device. Ends of optical fibers are ion polished. Micro-manipulators are used to position the polished end in abutting relationship with the optical device. A liquid which contains glass constituents is used to coat the junction of the optical fiber and the optical device. The liquid is subjected to a temperature cycle which fuses the glass constituents to the optical fiber and to the optical device.

Affixing an optical fiber to an optical device

Disclosed is a method of preparing a clear partially hydrolyzed aluminum alkoxide solution by mixing an aluminum alkoxide with about 0.4 to about 1 moles of water per mole of aluminum alkoxide in the presence of sufficient alcohol to give a maximum weight percent of equivalent alumina of 10%. The mixture is then heated until clear, which typically requires a temperature of about 40.degree. to about 60.degree. C. Then sufficient additional water is added to bring the number of moles of water per mole of alkoxide up to at least about 2. The water is added in the presence of sufficient alcohol to give a maximum weight percent of equivalent alumina of about 3%. A polymerized alumina glass can be prepared from the composition by heating it to a temperature of at least 500.degree. C.

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Churchill, PA, United States of America

Bulent E Yoldas