Uniform, Spherical Bridged Polysilsesquioxane Nano- and Microparticles by a Nonemulsion Method

A nonemulsion method to prepare spherical, monodisperse nanoparticles of bridged polysilsesquioxanes was developed. This is the first method to fabricate uniform spherical bridged polysilsesquioxanes from monomers with low to moderate hydrophilicity. The average particle size can be systematically controlled from similar to 20 nm to similar to 1.5 mu m. These particles have distinctive properties that include porosity without templating and buffering capacity. A mechanism for particle growth is proposed.