Abstract: A process for producing a metal oxide powder by flame spray pyrolysis where a) a stream of a solution containing at least one oxidizable or hydrolysable metal compound is atomized to afford an aerosol by means of an atomizer gas, b) this aerosol is brought to reaction in the reaction space of the reactor with a flame obtained by ignition of a mixture of fuel gas and air, c) the reaction stream is cooled and d) the solid product is subsequently removed from the reaction stream, wherein e) the reaction space comprises one or more successive double-walled internals, wherein the wall of the double-walled internal facing the flame-conducting region of the reaction space comprises at least one slot through which a gas or vapour is introduced into the reaction space in which the flame is burning and f) the slot is arranged such that this gas or vapour brings about a rotation of the flame.

Abstract: Process for producing a tungsten oxide powder or a tungsten mixed oxide powder of general formula MxWO3, wherein M=Na, K, Rb, Li and/or Cs, 0.1?x?0.5, comprising the consecutive steps of: a) providing a solution comprising respectively at least one tungsten compound and optionally at least one M-comprising compound in a concentration corresponding to the stoichiometry MxWO3, b) atomizing the solution, thus forming an aerosol, into a reaction space, c) reacting the aerosol in the reaction space with a hydrogen/oxygen flame for which the expression 1<O2,primary/0.5H2?3 applies, wherein the reaction space is configured such that it comprises two reaction zones with two different velocities of the reaction mixture v1 and v2 where v2=0.3-0.8 v1 and 0.5?v1?10 Nm/s, d) separating the solid from vaporous or gaseous substances and e) passing a reducing gas stream over the separated solid at a temperature of 450-700° C.

Abstract: A process for producing a metal oxide powder by flame spray pyrolysis where a) a stream of a solution containing at least one oxidizable or hydrolysable metal compound is atomized to afford an aerosol by means of an atomizer gas, b) this aerosol is brought to reaction in the reaction space of the reactor with a flame obtained by ignition of a mixture of fuel gas and air, c) the reaction stream is cooled and d) the solid product is subsequently removed from the reaction stream, wherein e) the reaction space comprises one or more successive double-walled internals, wherein the wall of the double-walled internal facing the flame-conducting region of the reaction space comprises at least one slot through which a gas or vapour is introduced into the reaction space in which the flame is burning and f) the slot is arranged such that this gas or vapour brings about a rotation of the flame.

Abstract: Process for producing metal oxide powders by means of flame spray pyrolysis, in which an aerosol comprising a metal compound is introduced into a flame in a reactor and reacted therein, and the metal oxide powder obtained is separated from gaseous substances, wherein a) the flame is formed by the ignition of an oxygen-containing gas (1) with a fuel gas, b) the aerosol is obtained by joint atomization of a solution containing a metal compound and an atomization gas by means of one or more nozzles and c) the ratio of the spray area to the cross-sectional reactor area is at least 0.2.

Abstract: Core-shell particles containing crystalline iron oxide in the core and amorphous silicon dioxide in the shell and in which a) the shell contains from 5 to 40% by weight of silicon dioxide, b) the core contains b1) from 60 to 95% by weight of iron oxide and b2) from 0.5 to 5% by weight of at least one doping component selected from the group consisting of aluminum, calcium, copper, magnesium, silver, titanium, yttrium, zinc, tin and zirconium, c) where the % by weight indicated are based on the core-shell particles and the sum of a) and b) is at least 98% by weight of the core-shell particles, d) the core has lattice plane spacings of 0.20 nm, 0.25 nm and 0.29 nm, in each case+/?0.02 nm, determined by means of HR-TEM.

Abstract: Process for producing metal oxide powders by means of flame spray pyrolysis, in which an aerosol comprising a metal compound is introduced into a flame in a reactor and reacted therein, and the metal oxide powder obtained is separated from gaseous substances, wherein a) the flame is formed by the ignition of an oxygen-containing gas (1) with a fuel gas, b) the aerosol is obtained by joint atomization of a solution containing a metal compound and an atomization gas by means of one or more nozzles and c) the ratio of the spray area to the cross-sectional reactor area is at least 0.2.

Abstract: A pulverulent cathode material contains at least one mixed oxide containing the metal components Li, at least one further metal component selected from the group consisting of Mn, Ni and Co. The pulverulent cathode material is produced by a process in which an ammonia-containing aerosol containing metal compound of the metal components is converted in a high-temperature zone of a reaction space and then the solids are removed.

Abstract: A process for producing a metal oxide powder proceeds by spray pyrolysis, in which a mixture comprising ammonia and an aerosol which is obtained by atomizing a solution containing a metal compound by means of an atomization gas is introduced into a high-temperature zone of a reaction space and reacted in an oxygen-containing atmosphere therein and the solids are subsequently separated off.

Abstract: Provided is a composite material which is in pellet form and which has particles with a core-shell structure, where the core of the particles has one or more magnetic materials, and the shell is made of silicon dioxide, and the pellet has one or more crosslinkable polyethylene and/or polyethylene-containing copolymers. Also provided is a process for crosslinking polyethylenes, by mixing the composite material, one or more free radical initiators, and at least one polyethylene, and heating the mixture inductively.

Abstract: Functionalized magnetic core-shell particles which are present predominantly in the form of isolated, essentially spherical individual particles, the core of which consists essentially of one or more magnetic iron oxides, the shell of which consists essentially of impervious, amorphous silicon dioxide, and the functionalization of which consists of amino or epoxy group units on the surface of the particles, and which additionally have a mean particle diameter d50 such that 2<d50<10 ?m, the particles have a content of iron oxide of 83 to 92% by weight, of silicon dioxide of 5 to 15% by weight, and of carbon of 0.5 to 3% by weight, the amino or epoxy group is part of the structural unit —OSi-alkyl-X where X is NH2 or epoxy and alkyl is C2-C8, and the concentration of the amino groups or of the epoxy groups is at least 30 ?mol/g of particles. The particles are used for immobilization of enzymes.

Abstract: Core-shell particles containing crystalline iron oxide in the core and amorphous silicon dioxide in the shell and in which a) the shell contains from 5 to 40% by weight of silicon dioxide, b) the core contains b1) from 60 to 95% by weight of iron oxide and b2) from 0.5 to 5% by weight of at least one doping component selected from the group consisting of aluminium, calcium, copper, magnesium, silver, titanium, yttrium, zinc, tin and zirconium, c) where the % by weight indicated are based on the core-shell particles and the sum of a) and b) is at least 98% by weight of the core-shell particles, d) the core has lattice plane spacings of 0.20 nm, 0.25 nm and 0.29 nm, in each case +/?0.02 nm, determined by means of HR-TEM.

Abstract: Iron-silicon oxide particles with a core and an outer shell have improved heating rates in a magnetic field. The core contains maghemite, magnetite, and haematite. The outer shell is essentially or exclusively silicon dioxide. The crystallite diameter of the haematite determined by X-ray diffraction is greater than 120 nm. A ratio of the brightness of the Debye-Scherrer diffraction ring by electron diffraction at a lattice plane spacing of 0.20+/?0.02 nm, comprising maghemite and magnetite, to the brightness of the Debye-Scherrer diffraction ring by electron diffraction at a lattice plane spacing of 0.25+/?0.02 nm, comprising maghemite, magnetite and haematite, is no more than 0.2.

Abstract: Composite material comprising—one or more heat-activatable free-radical initiators selected from the group consisting of organic peroxides and/or initiators having labile carbon-carbon bonds and particles which have a core-shell structure and the core of which comprises one or more magnetic materials, while the shell comprises silicon dioxide.

Abstract: Iron-silicon oxide particles with a core-shell structure, which have a) a BET-surface area of 10 to 80 m2/g, b) a thickness of the shell of 2 to 30 nm and c) a content of iron oxide of 60 to 90% by weight, of silicon dioxide of 10 to 40% by weight, based in each case on the enveloped particles, where d) the proportion of iron, silicon and oxygen is at least 99% by weight, based on the enveloped particles, and where e) the core is crystalline and the iron oxides comprise haematite, magnetite and maghemite, f) the shell consists of amorphous silicon dioxide and g) at least one compound or a plurality of compounds consisting of the elements silicon, iron and oxygen is/are present between shell and core.

Abstract: Iron-silicon oxide particles with a core and an outer shell have improved heating rates in a magnetic field. The core contains maghemite, magnetite, and haematite. The outer shell is essentially or exclusively silicon dioxide. The crystallite diameter of the haematite determined by X-ray diffraction is greater than 120 nm. A ratio of the brightness of the Debye-Scherrer diffraction ring by electron diffraction at a lattice plane spacing of 0.20+/?0.02 nm, comprising maghemite and magnetite, to the brightness of the Debye-Scherrer diffraction ring by electron diffraction at a lattice plane spacing of 0.25+/?0.02 nm, comprising maghemite, magnetite and haematite, is no more than 0.2.

Abstract: Fumed silicon dioxide powder with a BET surface area of 20 to 35 m2/g, characterized in that a) the number-based median particle diameter is 60 to 150 nm, and b) the proportion of particles with a diameter of 200 nm or more is at most 10%, and c) the proportion of particles with a diameter of up to 60 nm is at most 20%, based in each case on the total number of particles.

Abstract: Process for preparing a lithium-containing mixed oxide powder, wherein a) a stream of a solution containing at least one lithium compound and at least one metal compound of one or more mixed oxide components in the required stoichiometric ratio is atomized by means of an atomizer gas to give an aerosol having an average droplet size of less than 100 ?m, b) the aerosol is reacted in a reaction space by means of a flame obtained from a mixture of fuel gas and air, with the total amount of oxygen being sufficient for at least complete reaction of the fuel gas and of the metal compounds, c) the reaction stream is cooled and d) the solid product is subsequently separated off from the reaction stream.

Abstract: Mixed oxide which has the composition LixMn0.5?a Ni0.5?b Coa+b O2, where 0.8?x?1.2, 0.05?a?0.3, 0.05?b?0.3, ?0.1?a?b?0.02 and a+b<0.5, and has a BET surface area of from 3 to 20 m2/g, a multimodal particle size distribution and a d50 of less than or equal to 5 ?m. Mixed oxide which has the composition Lix Mn0.5?a Ni0.5?b Coa+b O2, where 0.8?x?1.2, 0.05?a?0.3, 0.05?b?0.3, ?0.1?a?b?0.02 and a+b<0.5, and has a BET surface area of from 0.05 to 1 m2/g, a d50 of less than or equal to 10 ?m and a ratio of the intensities of the signals at 2?=18.6±1° to 2?=44.1±1° in the X-ray diffraction pattern of greater than or equal to 2.4.

Abstract: Composite material comprising—one or more heat-activatable free-radical initiators selected from the group consisting of organic peroxides and/or initiators having labile carbon-carbon bonds and particles which have a core-shell structure and the core of which comprises one or more magnetic materials, while the shell comprises silicon dioxide.

Abstract: Composite material which is in pellet form and which comprises particles with a core-shell structure, where the core of the particles comprises one or more magnetic materials, and the shell comprises silicon dioxide, and which comprises a polyethylene crosslinkable in the presence of a heat-activatable free-radical initiator and/or polyethylene-containing copolymers. Process for the crosslinking of polyethylenes, by mixing the composite material, one or more heat-activatable free-radical initiator(s) and at least one polyethylene, and heating the mixture inductively.