Abstract:
Known processes for producing nanoparticles of compounds of the transition metals Zr, Ti, Ta, rare earths (RE), Mn and Fe via microemulsions lead to products which contain impurities from the starting materials, in particular water, and these make further use of the nanoparticles, for example in high-temperature superconductors (HTSC), difficult. It is proposed that the nanoparticles be produced via water-free microemulsions comprising an outer phase composed of a nonpolar solvent and an inner phase composed of a polar water-free solvent. The nanoparticles obtained have good monodispersity and can be used in the production of REBa2Cu3O7 superconductors by incorporation into the precursor coating solution.
Abstract:
The present invention refers to nanocrystaline spherical ceramic oxides, to the process for the synthesis and use thereof. These oxides, obtained by detonation of a water-in-oil emulsion (W/O), besides having a spherical morphology and nanocrystallinity, show a set of complementary features, namely a particle dimension inferior to 40 µm, bimodal particle size distribution, high purity, deagglomeration and stable crystalline stages. This set of features makes these powders particularly suitable for several applications such as coating processes, near net shape processes and, when applied in ceramics industry, they provide dense and porous ceramic objects of exceptionally high mechanical resistance.
Abstract:
Die vorliegende Erfindung betrifft sphärische Partikel enthaltend wenigstens ein Metall- und/oder Halbmetalloxid, wobei die Partikel einen mittleren Durchmesser von 10 bis 120 μm, eine BET-Oberfläche von 400 bis 800 m 2 /g und ein Porenvolumen von 0,3 bis 3,0 cm 3 /g aufweisen, der Durchmesser eines bestimmten Partikels an jeder Stelle dieses Partikels um weniger als 10% von dem durchschnittlichen Durchmesser dieses Partikels abweicht und die Oberfläche des Partikels im Wesentlichen glatt ist, sowie ein Verfahren zur Herstellung dieser sphärischen Partikel, einen teilchenförmiger Katalysator enthaltend die sphärischen Partikel und die Verwendung der sphärischen Partikeln als Katalysatoren oder Katalysatorträger.
Abstract:
A method for producing complex metal oxide having nano-sized grains comprises the steps of forming a mixture containing at least one metal cation dissolved in a solution and particulate material containing at least one further metal in the form of metal(s) or metal compound(s) and treating the mixture to form the complex metal oxide having nano-sized grains. The at least one further metal from the particulate material becomes incorporated into the complex metal oxide.
Abstract:
A method for producing fine spherical particles of a carbonate or a hydroxide of nickel, cobalt or copper which comprises dissolving a carbonate or a hydroxide of nickel, cobalt or copper represented by general formula (I): M(CO3)x/2 •(OH)y, wherein M represents Ni, Co or Cu, and x and y are numbers satisfying 0
Abstract:
The present invention refers to nanocrystaline spherical ceramic oxides, to the process for the synthesis and use thereof. These oxides, obtained by detonation of a water-in-oil emulsion (W/O), besides having a spherical morphology and nanocrystallinity, show a set of complementary features, namely a particle dimension inferior to 40 µm, bimodal particle size distribution, high purity, deagglomeration and stable crystalline stages. This set of features makes these powders particularly suitable for several applications such as coating processes, near net shape processes and, when applied in ceramics industry, they provide dense and porous ceramic objects of exceptionally high mechanical resistance.
Abstract:
A scintillation detector comprising nano-scale particles of a scintillation compound embedded in a plastic matrix is provided. The nano-scale particles may be made from metal oxides, metal oxyhalides, metal oxysulfides, or metal halides. Methods are provided for preparing the nano-scale particles. The particles may be coated with organic compounds or polymers prior to incorporation in the plastic matrix. A technique for matching the refractive index of the plastic matrix with the nano-scale particles by incorporating nano-scale particles of titanium dioxide is also provided. The scintillator may be coupled with one or more photodetectors to form a scintillation detection system. The scintillation detection system may be adapted for use in X-ray and radiation imaging devices, such as digital X-ray imaging, mammography, CT, PET, or SPECT, or may be used in radiation security detectors or subterranean radiation detectors.
Abstract:
The process described consists in controlled hydrolysis of metallic alkoxides using an emulsion containing inverse micelles of water in a hydrophobic solvent of the alkoxides and a surface active agent, followed by heat treatment of the polymer gel obtained. To prepare metallic oxide coatings, the reaction product is applied to a support when the hydrolysis is only partial.