In the 1930’s, it was discovered that a material could be produced that maintained its physical properties even when all water is removed and replaced with other materials. In the 1970’s, utilizing gas as the filler was shown to enhance the properties of aerogels without disruption to their structure. A popular form of aerogel in use now is composed of silica (SiO2), inorganic, lightweight, thermally and electrically conductive, porous solids.
A problem encountered by scientists and manufacturers of silica aerogels in the past was a loss of surface area and porosity, and an increase in density and bulk when chemicals or metallic gases were introduced in an attempt to further enhance certain features or properties of the composite. HCDS delivery via CVD proved to be an answer as HCDS allowed for a lower temperature and chemical deposition was uniform throughout all layers, leaving the structure intact while at the same time adding an extra benefit of increasing the compressive strength of the aerogel.
Today’s advanced SiO2 aerogels are used in many scientific and commercial applications including thermal insulation, detection of subatomic particles, microelectronics, solar, fiber optics, and cryogenics. Aerogels were incorporated as thermal insulation in the 2003 Mars Rover mission and have proven themselves in that gravity and environment. Specialized properties within aerogels has been found to enhance acoustics in ultrasonic and sonar applications and their structural stability allows them to serve as insulators in hydrogen fuel storage.