Editorial on Special Issues Aerogels and Aerogels 2018

摘要

Aerogels can be defined as ultralight materials with a 3D porous structure, similar to their parent wet gels, where the solvent has been replaced by a gas without a collapse of the gel structure, thanks to the drying process used (supercritical CO2 drying, freeze drying, etc.). These amazing materials usually present advantages in terms of surface area, diffusion properties, thermal conductivity, refractive index, and dielectric constant, which confer those exciting properties exploitable in many fields. The scope of applications for aerogels is broad and goes from insulation (thermal, acoustic) to storage and absorbing media, sensors, regenerative medicine, pharmaceuticals, and catalysis. The most publicized application to date is the use of silica-based aerogels by NASA as the insulating material in the Mars rover robot, used to gather information on the surface of Mars. The earliest aerogels synthesized were made of silica, but soon, many inorganic-based aerogels appeared, along with aerogels based on synthetic polymers (polyurea-based aerogels, for example), on biopolymers—often called bioaerogels—or aerogels based on hybrid organic–inorganic composite structures.