Aerogels have changed how a lot of high tech equipment is insulated. Resembling frozen smoke, the gel is lightweight and has extremely low thermal conductivity. However there’s always a downside, traditional aerogel material is brittle. Any attempt to compress it beyond 20% of its original size will change the material. Researchers at UCLA and eight other universities around the world have found a new form of ceramic aerogel that can compress down to 5% of its original size and still recover. It is also lighter and able to withstand extreme temperature cycles compared to conventional material. The full paper is behind a paywall, but you can view the abstract.
Traditional aerogel is more likely to fracture when exposed to high temperatures or repeated temperature swings, but the new material is more robust. Made from boron nitride, the atoms have a hexagonal pattern which makes it stronger.
The new material stood up to hundreds of exposures to sudden and extreme temperature spikes ranging from -198 C to 900 C over a few seconds. In a separate test, the gel lost less than 1 percent of its mechanical strength after being stored for one week at 1,400C.
Oddly, this material reacts differently to heating. Unlike most materials, it contracts as it gets hotter. This, apparently, has something to do with its ability to withstand thermal cycles and extremes better than other aerogels.
Aerogel makes great 3D printer insulation. We don’t know exactly how to make the special boron nitride material, but it is possible to create aerogels in a reasonable home lab.
from Hackaday https://ift.tt/2BWVwnH
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