Cellulose-Silica Nanocomposite Aerogels by In Situ Formation of Silica in Cellulose Gel

摘要

Aerogels with their low density (0.004-0.500 gcm~(-3)), large internal surface area, and large open pores are promising candidates for various advanced applications. The utilization of inorganic aerogels, however, has been hampered by their poor mechanical properties. A prominent example is silica aerogel, which is prepared by an organic sol-gel process, and has unique features, such as ultralow density (the lightest silica aerogel has a density that is similar to the density of air, which is 0.00129 gcm~(-3)), near transparency, and low thermal conductivity. However, the extreme fragility of this aerogel necessitates its reinforcement for practical uses. A typical method is hybridization with organic polymers, such as polyurea, polyurethane, poly(methyl methacrylate), poly-acrylonitrile, and polystyrene.