Uniform Pores in Cross-Linked Polymers by Dispersed Fumed Silica Templating

Hydrophobic fumed silica dispersions in organic monomers were explored as a pore-forming system in polymer synthesis. The method developed provides a simple and effective way of controlling the pore size in highly cross-linked polymers. Fumed silica suspensions in divinylbenzene were polymerized with subsequent etching of the silica particles, therefore creating the porosity in the polymer. The resulting polymers are mesoporous materials, exhibiting an extremely narrow pore size distribution with an average pore size of about 100 angstrom, replicating the size of the nanofiller. BET surface areas were found appreciably high (similar to 350 m(2)/g). Furthermore, the rheological behavior of the prepolymerization mixtures was studied to elucidate the formation of the porous network and showed that a tridimensional network of particles is formed at a minimum silica fraction (Phi(v)) of 0.08.