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 resulting in the formation of uniform polymer particles with narrow particle size distribution and high bulk density. Silica gel is widely used as layer material for TLC. Plaster of Paris is generally used as binding agent to hold silica gel firmly to the TLC plates. Silica gel is applied as sorbent to the aluminium foils.