Patent ID: 7919333
Filing Date: 2011-04-05
Classification: B82Y,G01N,H01F

Abstract:
1. A process for producing spherical magnetic silica gel particles comprising: a) converting alkoxysilanes into a hydrosol by acid catalysis with an acid as spherical magnetic silica gel particle precursors and then b) obtaining a hydrosol mixture by c) dispersing the hydrosol mixture in a dispersant which is immiscible with a phase of the hydrosol mixture and consolidating the hydrosol mixture by addition of a base during the dispersion process to obtain solid spherical magnetic silica gel particles; and d) converting the solid spherical magnetic silica gel particles by a thermal treatment to form thermally treated solid spherical magnetic silica gel particles (xerogels); wherein the admixing the SiO2 colloid with the hydrosol increases the surface area of the solid spherical magnetic silica gel particles (xerogels) and the magnetic particles cause the solid spherical magnetic silica gel particles to acquire magnetic properties.