14 DAY TRIAL // Often called 'frozen smoke', aerogels represent materials derived from a gel compound in which the liquid components have been switched with a gas. Despite the fact that their names suggests that they are gel-like, aerogel materials are anything but that. They are dry materials and have properties similar to that of a nanofoam, thus they have low densities and are excellent electrical and thermal isolators.
The first aerogel has been created in 1931 by Steven Kistler, due to a bet made with Charles Learned over who would be able to replace the liquid state into a jelly-like substance with gas, without reducing its original volume. Although the first aerogel has been produced on the basis of silica gels, Kistler developed over the years a series of other aerogels based on alumina, chromia, concluding with some of the latest designed materials that are carbon-based.
The general belief is that such low-density material would collapse the structure rather easily while applying even the lowest amount of force, however they are resilient materials capable of supporting relatively large weights in relation to their own. Nevertheless, every material must have a breaking point, thus while pressing on them with high pressure, the structure collapses on itself much in the same way as shattered glass does.
As they are about 99 percent air, it is natural that aerogel materials have a semi-transparent appearance and, while working with them over long periods of time, they require the use of gloves to prevent the appearance of brittle spots on the hands. The porous nature of the material makes aerogels feel dry on touch, has an expanded polystyrene texture and is a strong desiccant, meaning it has strong affinity towards water. However, chemical treatment can disable this feature.
As a composite material, it has multiple applications due to its incredible surface area, making it ideal for cleaning spills and altering the physical properties of some paints routinely used in the cosmetics industry. It was first used by NASA, in 1999, in its design of the StarDust spacecraft, and had the role of capturing tiny dust particles emitted from the coma of a comet. The StarDust mission was a compete success and the samples collected in the aerogel compound were returned to Earth seven years later.
It has exceptional heat insulating capabilities, with a melting temperature exceeding 1,200 degrees Celsius, and is often used as electric insulator in the fabrication of dielectric materials for supercapacitors. Aerogels are indeed incredible materials!