1768results about "Zirconium oxides" patented technology

A process for the production of ultrafine powders that includes subjecting a mixture of precursor metal compound and a non-reactant diluent phase to mechanical milling whereby the process of mechanical activation reduces the microstructure of the mixture to the form of nano-sized grains of the metal compound uniformly dispersed in the diluent phase. The process also includes heat treating the mixture of nano-sized grains of the metal compound uniformly dispersed in the diluent phase to convert the nano-sized grains of the metal compound into a metal oxide phase. The process further includes removing the diluent phase such that the nano-sized grains of the metal oxide phase are left behind in the form of an ultrafine powder.

Liquid feed flame spray pyrolysis of solutions of a metal oxide precursor which is an alkoxide or C_1-6 carboxylate and at least one second metal oxide precursor and/or second metal compound dissolved in oxygenated solvent by combustion with oxygen lead to the formation of sub-micron mixed-metal oxide powders not accessible by other processes or by the pyrolysis of metal chlorides or nitrates. The powders have numerous uses in advanced materials applications including particulate solid state lasers, advanced ceramic materials, and as catalysts in organic synthesis and automobile exhaust systems.

A new, cost effective process for the production of ultrafine particles which is based on mechanically activated chemical reaction of a metal compound with a suitable reagent. The process involves subjecting a mixture of a metal compound and a suitable reagent to mechanical activation to increase the chemical reactivity of the reactants and/or reaction kinetics such that a chemical reaction can occur which produces a solid nano-phase substance. Concomitantly, a by-product phase is also formed. This by-product phase is removed so that the solid nano-phase substance is left behind in the form of ultrafine particles. During mechanical activation a composite structure is formed which consists of an intimate mixture of nano-sized grains of the nano-phase substance and the reaction by-product phase. The step of removing the by-product phase, following mechanical activation, may involve subjecting the composite structure to a suitable solvent which dissolves the by-product phase, while not reacting with the solid nano-phase substance. The process according to the invention may be used to form ultrafine metal powders as well as ultrafine ceramic powders. Advantages of the process include a significant degree of control over the size and size distribution of the ultrafine particles, and over the nature of interfaces created between the solid nano-phase substance and the reaction by-product phase.

The invention is directed to a solid ion conductor which has a garnet-like crystal structure and has the stoichiometric composition L_7+xA_xG_3−xZr₂O₁₂, wherein

• • L is in each case independently a monovalent cation,
  • A is in each case independently a divalent cation,
  • G is in each case independently a trivalent cation,
  • 0≦x≦3 and
  • O can be partly or completely replaced by divalent or trivalent anion.

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are prepared by polymer templated methods and are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to ethane and/or ethylene. Related methods for use and manufacture of the same are also disclosed.

Doped, pyrogenically prepared oxides of metals and/or non-metals which are doped with one or more doping components in an amount of 0.00001 to 20 wt. %. The doping component may be a metal and/or non-metal or an oxide and/or a salt of a metal and/or a non-metal. The BET surface area of the doped oxide may be between 5 and 600 m2/g. The doped pyrogenically prepared oxides of metals and/or non-metals are prepared by adding an aerosol which contains an aqueous solution of a metal and/or non-metal to the gas mixture during the flame hydrolysis of vaporizable compounds of metals and/or non-metals.

Metal silicates or phosphates are deposited on a heated substrate by the reaction of vapors of alkoxysilanols or alkylphosphates along with reactive metal amides, alkyls or alkoxides. For example, vapors of tris-(ter-butoxy)silanol react with vapors of tetrakis(ethylmethylamido)hafnium to deposit hafnium silicate on surfaces heated to 300° C. The product film has a very uniform stoichiometry throughout the reactor. Similarly, vapors of diisopropylphosphate react with vapors of lithium bis(ethyldimethylsilyl)amide to deposit lithium phosphate films on substrates heated to 250° C. supplying the vapors in alternating pulse produces these same compositions with a very uniform distribution of thickness and excellent step coverage.

Methods and systems for processing metal oxides from metal containing solutions. Metal containing solutions are mixed with heated aqueous oxidizing solutions and processed in a continuous process reactor or batch processing system. Combinations of temperature, pressure, molarity, Eh value, and pH value of the mixed solution are monitored and adjusted so as to maintain solution conditions within a desired stability area during processing. This results in metal oxides having high or increased pollutant loading capacities and/or oxidation states. These metal oxides may be processed according to the invention to produce co-precipitated oxides of two or more metals, metal oxides incorporating foreign cations, metal oxides precipitated on active and inactive substrates, or combinations of any or all of these forms. Metal oxides thus produced are, amongst other uses; suitable for use as a sorbent for capturing or removing target pollutants from industrial gas streams or drinking water or aqueous streams or for personal protective respirators.

Disclosed are porous ceramic balls with a hierarchical porous structure ranging in size from nanometers to micrometers, and preparation methods thereof. Self-assembly polymers and sol-gel reactions are used to prepare porous ceramic balls in which pores ranging in size from ones of nanometers to tens of micrometers are hierarchically interconnected to one another. This hierarchical porous structure ensures high specific surface areas and porosities for the porous ceramic balls. Further, the size and distribution of the pores can be simply controlled with hydrophobic solvent and reaction time. The pore formation through polymer self-assembly and sol-gel reactions can be applied to ceramic and transition metals. Porous structures based on bioceramic materials, such as bioactive glass, allow the formation of apatite therein and thus can be used as biomaterials of bioengineering, including bone fillers, bone reconstruction materials, bone scaffolds, etc.

A fuel cell includes an electrolyte, a first electrode, and a second electrode. At least the first electrode comprises a nanostructured material.

Mesoscopically ordered, hydrothermally stable metal oxide-block copolymer composite or mesoporous materials are described herein that are formed by using amphiphilic block polymers which act as structure directing agents for the metal oxide in a self-assembling system.

A process of treating metal oxide nanoparticles that includes mixing metal oxide nanoparticles, a solvent, and a surface treatment agent that is preferably a silane or siloxane is described. The treated metal oxide nanoparticles are rendered hydrophobic by the surface treatment agent being surface attached thereto, and are preferably dispersed in a hydrophobic aromatic polymer binder of a charge transport layer of a photoreceptor, whereby π—π interactions can be formed between the organic moieties on the surface of the nanoparticles and the aromatic components of the binder polymer to achieve a stable dispersion of the nanoparticles in the polymer that is substantially free of large sized agglomerations.

Dental articles are produced using relatively low sintering temperatures to achieve high density dental articles exhibiting strengths equal to and greater than about 700 MPa. Ceramic powders comprised of nanoparticulate crystallites are used to manufacture dental articles. The ceramic powders may include sintering agents, binders and other similar additives to aid in the processing of the ceramic powder into a dental article. The ceramic powders may be processed into dental articles using various methods including, but not limited to, injection molding, gel-casting, slip casting, or electroforming, hand, cad/camming and other various rapid prototyping methods. The ceramic powder may be formed into a suspension, pellet, feedstock material or a pre-sintered blank prior to forming into the dental article.

Methods and compositions for depositing a metal containing film on a substrate are disclosed. A reactor and at least one substrate disposed in the reactor are provided. A metal containing precursor is provided and introduced into the reactor, which is maintained at a temperature of at least 100° C. A metal is deposited on to the substrate through a deposition process to form a thin film on the substrate.

The present invention includes a method of producing a crystalline metal oxide nanostructure. The method comprises providing a metal salt solution and providing a basic solution; placing a porous membrane between the metal salt solution and the basic solution, wherein metal cations of the metal salt solution and hydroxide ions of the basic solution react, thereby producing a crystalline metal oxide nanostructure.

A method and apparatus for producing metastable nanostructured materials employing a ceramic shroud surrounding a plasma flame having a steady state reaction zone into which an aerosol or liquid jet of solution precursor or powder material is fed, causing the material to be pyrolyzed, melted, or vaporized, followed by quenching to form a metastable nanosized powder that has an amorphous (short-range ordered), or metastable microsized powder that has a crystalline (long-range ordered) structure, respectively.

This invention relates to a 4 group metal oxide and to a method for preparation thereof and the 4 group metal oxide prepared by adding a particle growth inhibiter to a hydrosol a hydrogel or a dried product of a hydrous 4 group metal oxide represented by MO(2-x)(OH)2x (wherein M denotes a 4 group metal and x is a number greater than 0.1 or x>0.1) followed by drying and calcining has a specific surface area of 80 m<2>/g or more, a pore volume of 0.2 ml/g or more and a pore sharpness degree of 50% or more and excellent heat stability and is useful for a catalyst or a catalyst carrier in which a catalyst metal is dispersed to a high degree. This invention further relates to a porous 4 group metal oxide and to a method for preparation thereof and the 4 group metal oxide prepared by application of a pH swing operation is characterized by a large specific surface area, excellent heat stability, high dispersion of a catalyst metal and a controlled and sharp pore distribution and is useful for a catalyst or a catalyst carrier of excellent reaction selectivity.

A process to produce mixed metal oxides and metal oxide compounds. The process includes evaporating a feed solution that contains at least two metal salts to form an intermediate. The evaporation is conducted at a temperature above the boiling point of the feed solution but below the temperature where there is significant crystal growth or below the calcination temperature of the intermediate. The intermediate is calcined, optionally in the presence of an oxidizing agent, to form the desired oxides. The calcined material can be milled and dispersed to yield individual particles of controllable size and narrow size distribution.

Wet-chemical methods involving the use of water-soluble hydrolytically stable metal-ion chelate precursors and the use of a nonmetal-ion-containing strong base can be used in a coprecipitation procedure for the preparation of ceramic powders. Examples of the precipitants used include tetraalkylammonium hydroxides. A composition-modified barium titanate is one of the ceramic powders that can be produced. Certain metal-ion chelates can be prepared from 2-hydroxypropanoic acid and ammonium hydroxide.

Micelle-templated superficially porous particles having a solid core and an outer porous shell with ordered pore structures and a narrow particle size distribution, such as about ±5% (one sigma), and a high specific surface area of about 5 to about 1000 m²/g.

A method for producing fine particles of metal oxide characterized in that metal halide is hydrolyzed in the presence of organic solvent. According to this invention, under hydrolysis of titanium tetrachrolide, anatase type titanium oxide can be obtained by selecting hydrophilic organic solvent, and rutile type titanium oxide can be obtained by selecting hydrophobic organic solvent.