Aerogel - Applications

Applications

There is a variety of applications for which aerogels are used.

• Commercially, aerogels have been used in granular form to add insulation to skylights.
• Transparent silica aerogel would be very suitable as a thermal insulation material for windows, significantly limiting thermal losses of buildings. One research team has shown that producing aerogel in a weightless environment can produce particles with a more uniform size and reduce the Rayleigh scattering effect in silica aerogel, thus making the aerogel less blue and more transparent.
• Its high surface area leads to many applications, such as a chemical adsorber for cleaning up spills (see adsorption). This feature also gives it great potential as a catalyst or a catalyst carrier.
• Aerogel particles are used as thickening agents in some paints and cosmetics.
• Aerogels are being tested for use in targets for the National Ignition Facility.
• Aerogel performance may be augmented for a specific application by the addition of dopants, reinforcing structures, and hybridizing compounds. Using this approach, the breadth of applications for the material class may be greatly increased.
• Commercial manufacture of aerogel 'blankets' began around the year 2000. An aerogel blanket is a composite of silica aerogel and fibrous reinforcement that turns the brittle aerogel into a durable, flexible material. The mechanical and thermal properties of the product may be varied based upon the choice of reinforcing fibers, the aerogel matrix, and opacification additives included in the composite.

• NASA used aerogel to trap space dust particles aboard the Stardust spacecraft. The particles vaporize on impact with solids and pass through gases, but can be trapped in aerogels. NASA also used aerogel for thermal insulation of the Mars Rover and space suits.
• The US Navy is evaluating aerogel undergarments as passive thermal protection for divers.
• Aerogels are used in particle physics as radiators in Cherenkov effect detectors. ACC system of the Belle detector, used in the Belle Experiment at KEKB, is a recent example of such use. The suitability of aerogels is determined by their low index of refraction, filling the gap between gases and liquids, and their transparency and solid state, making them easier to use than cryogenic liquids or compressed gases. Their low mass is also advantageous for space missions.
• Resorcinol–formaldehyde aerogels (polymers chemically similar to phenol formaldehyde resins) are mostly used as precursors for manufacture of carbon aerogels, or when an organic insulator with large surface is desired. They come as high-density material, with surface area about 600 m2/g.
• The first residential use of aerogel as an insulator is in the Georgia Institute of Technology's 2007 Solar Decathlon House where it is used as an insulator in the semi-transparent roof.
• Metal–aerogel nanocomposites can be prepared by impregnating the hydrogel with solution containing ions of a transition metal. The impregnated hydrogel is then irradiated with gamma rays, leading to precipitation of nanoparticles of the metal. Such composites can be used as catalysts, sensors, electromagnetic shielding, and in waste disposal. A prospective use of platinum-on-carbon catalysts is in fuel cells.
• Aerogel can be used as a drug delivery system owing to its biocompatibility. Due to its high surface area and porous structure, drugs can be adsorbed from supercritical CO₂. The release rate of the drugs can be tailored based on the properties of aerogel.
• Carbon aerogels are used in the construction of small electrochemical double layer supercapacitors. Due to the high surface area of the aerogel, these capacitors can be 1/2000th to 1/5000th the size of similarly rated electrolytic capacitors. Aerogel supercapacitors can have a very low impedance compared to normal supercapacitors and can absorb or produce very high peak currents. At present, such capacitors are polarity-sensitive and need to be wired in series if a working voltage of greater than about 2.75 V is needed.
• Dunlop has recently incorporated aerogel into the mold of its new series of tennis racquets, and has previously used it in squash racquets.
• Chalcogels have shown promise in absorbing the heavy metal pollutants mercury, lead, and cadmium from water.
• Aerogel can introduce disorder into superfluid helium-3.
• Arms control experts speculate it is used to transform radiation into pressure in multistage nuclear weapons.