Silica gel is a rigid 3D network of colloidal silica. It is exclusively used as a support material for the active titanium(III) centers in Ziegler-Natta catalysts. Silica gel allows a controlled fragmentation leading to form uniform polymer particles with narrow particle size distribution and high bulk density. Silica gel is classified as below:
a. Aquagel - pores are filled with water
b. Xerogel - by the process of evaporation, aqueous phase in the pores are removed
c. Aerogel - solvent removed by supercritical extraction
Silica gel was used to compare MCM-41 type mesoporous adsorbents.
Silica gel has been used as a column material in the preparation of nanoscale iron oxide−based materials to be used in the catalysis of different hydrogenation reactions, which is monitored using gas chromatography (GC) technique.