Transparent Silica aerogel fiber felt composite shell
Silica-Aerogels are very well investigated and a granular form is available on the market as well as glass fiber felts infiltrated with silica aerogels. Both are used for instance as superinsulators for building applications, green houses, shoe soles, wrapping around pipelines. These conventional materials have some drawbacks and therefore still new materials are developed worldwide. One of the new variants which came up in the last years are flexible, rubber-like silica aerogels. They are soft and can be compressed by more than 50% and recover completely. These new type can be easily wrapped around tubes, be compressed, has a fine haptic and do not develop dust on touching them. The new flexible aerogels have, however, currently a drawback, they are just at the verge of being superinsulators, that is their heat conductivity is still above 0.02 W/mK. They have to be improved to become comparable to the brittle, hard silica aerogels well-known since 30 years.
The research at DLR concentrates on relations between chemical composition, synthesis and drying procedures and the nanostructure developing. The new silcia aerogels shall be developed to withstand temperatures up to 600°C without decomposition or becoming brittle and aside their processing and handling shall be improved. The handling can be for instance largely improved by reinforcement of the aerogels with polymeric and glass fiber felts without too much loss of thermal conductivity. The main application fields looked for are in the area of motors, exhausts and furnaces.