Structural inhomogeneities in wide-pore silica gels

Abstract

The cause of a bimodal or multimodal pore-size distribution in wide-pore silica gels made by a calcination procedure were elucidated. It was found that the process of crystallization of salt out of the pores of the silica gel is influenced by the nature of the salt and by the rate of evaporation of water. If these parameters were optimized, the pore structure of wide-pore silica gel prepared by this method was more uniform and the batch-to-batch repeatability of the process was greatly improved.