What makes aerogel so special?
The fact that typical aerogels are between 95 and 99.5 percent porous gives them their unusual characteristics. Because of this highly porous quality they are characterized by extremely high surface area, high thermal and acoustical resistivity, low dielectric constant, and low refractive index. There are other materials that exhibit each of these properties, however, only aerogel exhibits all of these properties at the same time.
