| 20110259244 | Nanoparticulate Titanium Dioxide Particles with a Crystalline Core, a Metal-Oxide Shell and an Outer Skin Containing Organic Groups, and Method for the Manufacture Thereof - This invention refers to particles with a crystalline core of titanium dioxide that has an average diameter of ≦30 nm measured with the XRD/Scherrer method, a shell made of a metal oxide that has no photocatalytic properties and an outer skin that carries organic radicals. A suspension of these particles is conveniently prepared with a process that encompasses the following steps: The supply of a dispersion that has crystalline titanium dioxide particles having an average diameter of ≦30 nm whose surface has been modified with organic groups in solution that contains a dissolved, hydrolytically condensable compound of a metal M whose oxide should form the shell mentioned above, in which case an organic solvent or a mixture of an organic solvent and water is used as solvent, and adjusting the pH of the solution in such a way that a full deagglomeration of the nanoparticles occurs, the stirring of the dispersion in the presence of a sufficient quantity of water for the hydrolytic condensation of the dissolved, hydrolytically condensable compound of the metal M until the organic constituents with which the modified TiO | 10-27-2011 |
