Patent ID: 7737189

Claim:
A process for the preparation of monolithic silica/latex hybrid xerogels and aerogels under subcritical conditions, comprising the following steps: synthesizing a hybrid gel in a mixture, comprising in a first stage acid hydrolysis of a silicon alkoxide with excess water in an organic solvent to prepare a hydrolysed sol, after which in a second stage the hydrolysed sol is subjected to polycondensation under alkaline conditions to prepare a hybrid gel in a wet state; pre-prepared colloidal polymer particles, containing alkoxysilane group, in the form of an aqueous dispersion & are incorporated in the above mixture, either in the first stage for co-hydrolysis with the silicon alkoxide, or in the second stage for co-condensation with previously hydrolysed colloidal silica; after the polycondensation hybrid gels are aged, washed with a washing solvent, and then dried under subcritical conditions in an atmosphere almost saturated with washing solvent to prepare the hybrid gel in dry state; the hybrid gel in a dry state has a density of 300-1300 kg/m 3 , a porosity of 40-85%, a specific surface area of 400-900 m 2 /g and a mean pore diameter of 2-12 nm.