A novel preparation of macroscopic beads of porous silica

Abstract

We report a new method for preparing porous silica beads using a high internal phase emulsion (HIPE) sol–gel templating method. The method uses a silica sol based HIPE and does not rely on a polymeric support to produce the final structure. As a result beads may be formed readily in large numbers. The beads have an open porous structure commensurate with the formation of a HIPE precursor phase. We also describe how the rheology of the HIPE reflects the formation of an open porous structure and how the viscosity of the HIPE can affect the shape of the beads and how HIPE destabilization may be used to vary the pore size.