Nanotechnology - Aerogel
The evolution of thermal insulation
Aerogel is a solid nanoporous substance created at an experimental level by Steven Kistler, in 1931 and brought to attention for its use on suits and jackets worn by the NASA astronauts.
This material is created by gelifying silica in a solvent.
When removing the solvent what’s left basically is “inflated sand” that has up to 99% porosity.
Nanopores are so thick and numerous that they slow down heat and mass conductivity thus providing an extremely low thermal conductivity value.
The two innovations introduced by Aspen have changed Aerogel from a simple laboratory experiment into a widely-used industrial product:
- the extraction process, using supercritical CO2, reduces Aerogel‘s formation cycle from months to hours.
- Aerogel‘s transformation process in an insulating slab provides mechanical integrity and shapes that can be suited for any use.
Aerogel is a universal solution
Aerogel can be used in a temperature range from – 200°C to + 650°C, in other words in the majority of both common and industrial uses. The product range can cover all these temperatures.
Aerogel is found in highly specialized technological sectors (aerospace, shipbuilding, automotive), in standard building work, electronic appliances and industrial plants, all of which require efficiency with a view to saving energy and costs.
- The term “gel” derives from the extraction process which creates the nanoporosity formation.
- Aerogel’s pores have a 1/10.000 diameter in comparison to human hair.
- As a result of its transparency aerogel is called “smoked ice”.
- Nanoporous material has a large internal surface and is expressed by the sum of the surface of all its nanopores.
A 1 cm³ Aerogel cube made of carbon can have an internal surface of over 1000 m².
- The first jacket with Aerogel padding, made in 1999, is called “Absolute Zero”. Subsequently the jacket was perfected in the Antarctic areas. It was worn in the harshest climate on the planet and easily passed all tests.
- A layer of Aerogel , only 3 mm thick, can protect a human body even in temperatures at -50 °C.
- In 1999, Aerogel was sent into space for 5 years in the German-made dust analyzer CIDA. It traveled over 3 billion kilometers collecting the “Wild 2” comet’s dust.
- Aerogel is known for its ground-breaking records in insulating materials: it made it to the top of the Everest and in the Antarctic in the wake of daring expeditions, it is used on oil pipelines in the deep ocean and it is used in the cosmos to protect parts of spacecrafts.