Technology Spotlight: Aerogel Insulation

Synthetic, porous  material derived from a gel, in which the liquid component of the gel has been replaced with a gas, Aerogels are the world’s lightest solid materials, composed of up to 97% air by volume.

Transparent superinsulating silica aerogels exhibit the lowest thermal conductivity of any solid known. The solids in silica aerogels consist of very small, three-dimensional, intertwined clusters that comprise only 3% of the volume. Conduction through the solid is therefore very low. The remaining 97% of the volume of aerogels is composed of air in extremely small nanopores. The air has little room to move, inhibiting both convection and gas-phase conduction.

These properties account for the incredible effectiveness of aerogels as having an extremely low thermal conductivity: from 0.03 W/(m·K) in atmospheric pressure down to 0.004 W/(m·K) in modest vacuum, which correspond to R-values of 14 to 105 (US customary) or 3.0 to 22.2 (metric) for 3.5 in (89 mm) thickness.

For many years, aerogels had been relegated the lab curiosity status and used only in the highly specialized applications. For example, NASA used an 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.

Despite their unique properties, the commercial applications of aerogels were limited. However, over the last two decades, Aspen, the company that initially developed the flexible aerogel blanket insulation used in NASAs space suits, led the way in commercializing silica aerogel blanket material for broader thermal insulation applications.  By 2004, aerogel materials were being used in products selected for use by the Special Forces of the US Military, and the Canadian Ski Team. Shortly thereafter, aerogel insulation blanket materials aimed at industrial, energy, cryogenic and subsea applications appeared on the market.

In 2004, about US$25 million of aerogel insulation products were sold globally. Since then the market has grown substantially to approximately US$500 million today. Continued growth is expected as the potential to replace conventional insulation with aerogel solutions in the building and industrial insulation sectors is significant.

InsulTech is constantly monitoring developments in materials science and recognized early the potential of aerogels. InsulTech has developed engineering and manufacturing capabilities to utilize aerogel materials in thermal insulation blankets for industrial, energy, marine and aerospace applications.