Has aerogel technology progressed since that time?
Not much happened again until the late 1970s. At that time the French government asked Stanislaus Teichner at Universite Claud Bernard in France to help develop a method for storing oxygen and rocket fuels in porous materials. Frustration with the time-consuming (several weeks) and laborious solvent exchange process invented by Kistler led to the idea of using a sol-gel process. This process replaced the sodium silicate with an alkoxysilane. Hydrolyzing this in a solution of methanol produced a gel in a single step. This eliminated both the water-to-alcohol exchange step and the presence of inorganic salts in the gel. Drying these alcogels under supercritical alcohol conditions resulted in high-quality silica aerogels. This approach was subsequently extended by Teichner’s group and others to producing a wide variety of metal oxide aerogels. Thereafter, the number of researchers in the field increased and progress occurred at a much more rapid rate.
