Alcohols homogeneous metal catalysed

The sol-gel technique uses mild conditions to prepare a cross-linked, robust metal oxide gel. Gelation of silanes, such as tetraethoxysilane (TEOS) or sodium silicate, involves the use of aqueous solutions, sometimes containing alcohol, with a slight adjustment of pH to catalyse the condensation polymerisation. The cross-link density, material porosity and homogeneity of functionalised sites, are dependent on the solution pH, extent of ageing, method of solvent evaporation, water content in solution and type of catalyst, all of which provide a number of handles to modify the material of interest. 

---