Encapsulation of In Situ Nanoprecipitated Inorganic Materials in Confined Geometries Into a Polymer Shell Using Inverse Miniemulsion

Highly insoluble inorganic nanoparticles can be prepared in situ by precipitation inside of aqueous nanodroplets of cosonicated inverse miniemulsions containing salts, which are readily soluble in water. If the different salt droplets are fused, a hardly soluble salt is formed in the dispersed phase with a size considerably smaller than the size of the droplets. Subsequent encapsulation of the nanoparticles into a polymer shell is achieved by an interfacial polyaddition reaction between a polyol present in the aqueous phase and a (second) monomer (2,4-toluene diisocyanate (TDI)) in the continuous phase. The materials are studied by transmission electron microscopy, X-ray diffraction, dynamic light scattering (DLS), and TGA.