Spherical, magnetic SIO₂ particles with an adjustable particle and pore size and an adjustable magnetic content, method for producing them and use of SIO₂particles of this type

摘要

The invention relates to a method for producing magnetic SiO2 particles, comprising the following steps: a) alkoxysilanes are dispersed in water, acid-catalytically hydrolyzed and condensed to form an SiO2 hydrosol; b) a magnetic particle-sol mixture is produced by adding magnetic particles, for example usual magnetic particles, magnetic colloids and/or ferrofluids to the SiO2 hydrosol; c) dispersing the magnetic particle-sol mixture in an organic solvent which is immiscible with water; and d) adding a base to the magnetic particle-sol mixture during or after the dispersion in the organic solvent in order to form a gel.