Nanostructured interpenetrated organic-inorganic aerogels with thermal superinsulating properties

Organic-inorganic composite aerogels were synthesized via a facile one-step impregnation of a wet hydrophobic cellulose II matrix with polyethoxydisiloxane solution followed by in situ NH₄OH-catalysed formation of a nanostructured mesoporous silica network. The silica phase was subsequently hydrophobised with hexamethyldisilazane. By tuning synthesis conditions, organic-inorganic composite aerogels with various morphology (from meso- to macroporous), specific surface area (from 200 to 850 m²/g) and hydrophilic-hydrophobic balance (from fully hydrophilic to highly hydrophobic) were prepared after supercritical CO₂ drying. The obtained organic-inorganic aerogels are monolithic, resistant to humidity and thermally superinsulating with the thermal conductivity 0.021–0.022 W/(m·K) in room conditions.