Several aerogels of cellulose–silica nanocomposites were prepared by sol-gel method application. The in situ formation of silica in the cellulose gel was obtained with tetraethyl orthosilicate (TEOS) precursor and drying with supercritical CO2 was required for conversion of composite to aerogel . While another working group approach to prepare aerogels involved methoxytrimethylsilane (MTMS) as silica precursor, the aerogel was obtained by using a freeze dryer . Both reports are very successful but also very energy demanding and time consuming, since several days are required to reach the product. Another group prepared organic–inorganic hybrids of cellulose–silica incorporated with polyhedral oligomeric silsesquioxanes (POSS) by using γ-aminopropyltriethoxy silane (γ-APTES) as a crosslinking agent. Even though the POSS amine particles are well dispersed at the nanometer scale throughout the cellulose matrix, this method is costly .