| 摘要 |
<p>Particle comprises a crystalline core of titanium dioxide with an average diameter of >= 30 nm, measured by X-ray diffraction/Scherrer-method, a shell (I) from a metal oxide with no photocatalytic characteristics, and a shell (II) containing an organic residue. Independent claims are included for: (1) the preparation of the particle comprising providing a dispersion containing surface modified organic groups and crystalline titanium dioxide particle with a diameter of = 30 nm in a solution containing dissolved hydrolytic condensable compound of a metal or its oxide, where the solvent is an organic solvent or a mixture of the organic solvent and water, adjusting the pH value of the solution such that a complete deagglomeration of the nanoparticle takes place, agitating the dispersion in the presence water quantity enriched for the hydrolytic condensation of the dissolved hydrolytic condensable compound of the metal until the organic components with the modified titanium dioxide particles are displaced to form an oxidic shell of the metal, at least partially removing the solvent, preferably water from the product and adding a component, which modifies the surface of the oxidic shell to the product and effecting the obtained shell (II) on the particles to obtain a dispersion of surface modified particle; and (2) the preparation of the dispersion comprising providing a colloidal dispersed solution, which is produced by hydrolysis of complexed titanium halide or -alkoxide after the Sol-Gel procedure from soluble precursor in an organic solvent, concentrating the obtained solution at 50-100[deg] C for removing unreacted starting materials and light volatile products; and collecting the product in an organic solvent to obtain a solution, where the obtained solution is autoclaved in a closed pressure container, where the collection of the product and the autoclaving step takes place in an organic solvent containing = 10, preferably 5 w.% of starch and = 2.5 wt.% of water.</p> |
