Self-catalyzed synthesis of organo-silica nanoparticles

A procedure has been developed which utilizes aminopropyl-triethoxysilane ( APS) as the catalyst and a comonomer in the production of hybrid organo-sil ica nanoparticles, Particles ranging from ca. 100 to 500 nm can be prepared using organo-silanes of the type R'Si(OR)(3), where R ' = Me, vinyl, allyl , or other hydrophobic groups and R = Me or Et, in a water/surfactant solut ion, Based on elemental analysis, up to 10 mol % of APS was incorporated in to the siloxane particle network. It is thought that the amino groups are l ocated mainly on the surface due to their hydrophilicity and APS' relativel y slow rate of hydrolysis and condensation.