Patent ID: 8563620

Claim:
A method for synthesis of a silica monolith according to a sol-gel process including the following steps: hydrolyzing a silicon alkoxide in order to form a hydrolyzed precursor followed by condensing said hydrolyzed precursor in the presence of an organic solvent, in the presence of water and a basic catalyst in order to form oligomeric clusters containing several silicon atoms; dispersing said oligomeric clusters in a solution in order to form a sol; polymerizing the sol in order to obtain a gel by a first heat treatment, at a temperature below the boiling temperature of the constituents of the sol; drying the gel by a second heat treatment including exposure of the gel to about 90° C. for at least 24 hours followed by an increase in temperature in vacuo between about 90° C. and about 180° C., said increase in temperature being comprised between 0.1° C./min and 5° C./min; transforming the gel into a xerogel by a third heat treatment, said third heat treatment including a hold at a drying temperature comprised between 850 and 1,000° C. for at least one hour; dehydrating and densifying the xerogel until a silica monolith is obtained by a fourth heat treatment, said fourth heat treatment comprising a hold at a dehydrating and densifying temperature above 1,100° C. for at least one hour.