Production of porous gels and ceramic materials

A process for the production of a porous ceramic material comprising adding solid primary particles of an inorganic substance, produced by a vapor phase condensation method, to a quantity of liquid sufficient to form a sol and dispersing the solid primary particles therein to form a sol containing colloidal particles which are aggregates of the primary particles, drying the sol to produce a porous gel without hydrothermal treatment to enlarge the pores, the gel having a porosity of at least 0.70, and with 70 percent of the pore volume contained within pores having a size in the range of .+-.25 percent of the mean, and heating the gel to form a porous ceramic material.

A process for the production of a porous gel of an inorganic substance having selected pore size and specific surface area properties without hydrothermal treatment to enlarge the pores, comprising adding solid primary particles of the substance, produced by a vapor phase condensation method, to a quantity of liquid sufficient to form a sol and dispersing the solid primary particles therein to form a sol containing colloidal particles which are aggregates of the primary particles, and drying the sol to produce a porous gel having a porosity of at least 0.70 and with 70 percent of the pore volume contained within pores having a size in the range of .+-.25 percent of the mean, said solid primary particles being selected to be of a size appropriate for producing the selected pore size and specific surface area properties in the porous gel.