Background

Aerogels are a diverse class of porous, solid materials that exhibit an array of unique material properties. Aerogels are known for their ultralow densities (which range from 0.0011 to ~0.5 g cm-3). Essentially an aerogel is the dry, low-density, highly porous, solid framework of a gel that is isolated from its liquid component. Aerogels are open-porous (that is, the gas in the aerogel is not trapped inside solid pockets) and have pores in the range of <1 to 100 nanometers in diameter and usually <20 nm. Aerogels are produced by extracting the liquid component of a gel through supercritical drying or freeze-drying. This allows the liquid to be slowly dried without causing the solid matrix in the gel to