A nanocomposite includes a plurality of nanoparticles, where each nanoparticle of the plurality of nanoparticles includes a TiO.sub.2 nanoparticle core characterized by a diameter between about 1 nm and about 20 nm and a surface .OH density below about 6.OH/nm.sup.2, and a nanoparticle shell conformally formed on surfaces of the TiO.sub.2 nanoparticle core. The nanoparticle shell is continuous and is thinner than about 2 nm. The nanoparticle shell includes a transparent material with a refractive index greater than about 1.7 for visible light. A valence band of the nanoparticle shell is more than about 0.1 eV lower than a valence band of the TiO.sub.2 nanoparticle core. A conduction band of the nanoparticle shell is more than about 0.5 eV higher than a conduction band of the TiO.sub.2 nanoparticle core.

Compositions having solid core particles with functionalizing layers over at least a portion of the outer surfaces of the solid core particles are described. The functionalizing layers are formed from a reaction product of a 1,1-di-activated vinyl compound, or a multifunctional form thereof, or a combination thereof.

Provided are a titanium dioxide aqueous dispersion having high dispersibility and little aggregation or coarse particles, and a method for producing the same. The titanium dioxide aqueous dispersion contains titanium dioxide particles having a hydrophobic compound such as a higher fatty acid or a salt thereof on the surface, an aqueous dispersion medium, a nonionic surfactant having an HLB value of 10 or higher, and a basic compound such as an alkanolamine, and the pH is in the 8.5-13 range. The method for producing a titanium dioxide aqueous dispersion has a step for mixing the titanium dioxide particles having a hydrophobic compound on the surface, the aqueous dispersion medium, the nonionic surfactant having an HLB value of 10 or higher, and the basic compound to bring the pH of the aqueous dispersion into the 8.5-13 range.

Core particles produced in situ or introduced as preformed core particles are coated with a layer of carbon. Non-carbon as well as some carbon-based core materials can be utilized. The resulting carbon coated particles can find applications in rubber products, for instance as reinforcement for tire components.

Provided are: dispersion in which titanium dioxide microparticles are highly dispersed in an organic solvent; and a method for producing the dispersion.

The dispersion comprises at least titanium dioxide microparticles, an organic solvent, a silane coupling agent, and a dispersant having a basic adsorptive group, wherein the ratio of the mass of the dispersant to that of the silane coupling agent is 15 to 75% by mass. It is preferred that the ratio of the total mass of the silane coupling agent and the dispersant to the mass of the titanium dioxide microparticles is 10 to 40% by mass. The dispersion is produced by dispersing the titanium dioxide microparticles together with the above-specified amounts of the silane coupling agent and the dispersant having a basic adsorptive group in the organic solvent.

The present invention is a composition comprising an aqueous dispersion of metal oxide pigment particles coated with an organosilane polymer comprising structural units of an alkyltrihydroxysilane or a salt thereof, a dialkyldihydroxysilane or a salt thereof, and an ancillary alkylsilane triol. The composition of the present invention provides hydrophobicity to pigment particles, thereby imparting water resistance, and allows for high loadings of pigment in water without increased viscosity. The dispersion is further useful for providing stain and corrosion resistance in coatings arising from paints.

The present invention relates to a process for preparing oxide particles, in particular metal oxide particles, coated with silicon oxide by means of flame spray pyrolysis technology, to oxide particles, in particular metal oxide particles, coated with silicon oxide, and to a composition comprising said particles. The present invention also relates to specific oxide particles, in particular metal oxide particles, coated with silicon oxide derived from such a process, to the compositions comprising such particles and also to the uses thereof.

Provided is a charge-adjustment powder having an excellent ability to regulate a charging property on a surface of a target to be charge-adjusted within a certain range, and to maintain the applied charge. The charge-adjustment powder is formed with particles having titanium-niobium oxide on at least a part of a surface of a core, and the content of an alkali metal is set to be 20.0 mmol/kg or less based on the whole.

There has been demand for a titanium oxide organosol that has a high transparency and a high refractive index and that also exhibits an excellent viscosity stability over time. The rutile-type titanium oxide organosol according to the present invention comprises a silane coupling agent, a basic additive acting as a deflocculant, a water-insoluble solvent, and rutile-type titanium oxide particles that have been surface-treated with a hydrous oxide of at least one metal species selected from Zr, Ce, Sn, and Fe, the rutile-type titanium oxide organosol being characterized in that the Ti ratio contained in the colloidal particles in the rutile-type titanium oxide organosol is at least 60 mass% when calculated as the oxide, and the ratio of metal species at the colloidal particle surface derived from x-ray photoelectron spectroscopy is 20-50 mass%.

Provided is a method for producing a zirconia-coated titanium oxide fine particle dispersion which includes (1) a step of preparing a dispersion (1) of titanium oxide fine particles, (2) a step of adding, to the dispersion (1), 1 to 50 parts by mass of an aqueous peroxozirconic acid solution in terms of the mass of ZrO.sub.2 per 100 parts by mass of the titanium oxide fine particles, and then aging reaction fine particles (2a) obtained as a result of a reaction between the titanium oxide fine particles and the peroxozirconic acid to thereby obtain a dispersion (2) of a zirconia-coated titanium oxide fine particle precursor (2b), and (3) a step of adjusting the dispersion (2) to have a solid concentration of 0.01 to 10 mass % and then hydrothermally treating the resulting dispersion (2).