Porous silica by the sol-gel process

In order to prepare porous silica that is mesoporous or microporous, the sol-gel process is recommended. Unlike methods that require high temperatures, the sol-gel process produces porous silica more or less at room temperature. The process involves the hydrolysis and polycondensation of silicon alkoxides in the majority of cases. Colloidal silica and soluble silicates may be used as well. The processing parameters that influence the porosity are primarily the pH and aging. Applications using porous silica to encapsulate sensor molecules and enzymes are developing rapidly.