Silica nanocapsules produced from nanoemulsions by phase inversion.


A process for prodn. of silica nanocapsules comprises (a) obtaining a nanoemulsion of an aq. phase and an oil phase and at least one surfactant, the nanoemulsion being formed by the process comprising (i) forming an oil-in-water (O/W) emulsion of an aq. phase and an oil phase comprising at least one hydrophobic material and at least one silica precursor in the presence of at least one surfactant, (ii) heating the O/W emulsion above its phase inversion temp. (PIT) to obtain a water-in-oil (W/O) emulsion, and (iii) cooling the W/O emulsion below the PIT temp., thereby forming a nanoemulsion of oil droplets in water, and (b) inducing interfacial polymn. of the silica precursor around the oil droplets in the nanoemulsions thereby obtaining the silica nanocapsules. The hydrophobic material is selected from a wide range of oils and waxes, and the process may be used to encapsulate drugs, bioactive compds., cosmetic materials, flavoring agents, colorants, and antioxidants. [on SciFinder(R)]


CAPLUS AN 2010:1161173(Patent)