A new insulation material is practically weightless yet still durable

[Judi Lynn]

The porous aerogel is at least 99 percent air
BY MARIA TEMMING 2:00PM, FEBRUARY 14, 2019



DAINTY INSULATOR A new insulator that’s at least 99 percent open space can withstand extreme heat that would obliterate other substances.

X. XU, X. DUAN

A new, nearly weightless insulation material can withstand extreme heat that would destroy other materials.

The porous aerogel is at least 99 percent open space, with the rest made up of an atomically thin ceramic called hexagonal boron nitride. The design proves extremely durable under high temperatures and rapid temperature shifts of over 1,000 degrees Celsius, researchers report in the Feb. 15 Science.

“It’s notoriously hard to make materials that are not just lightweight, but can also be heavily heat resistant,” says Deep Jariwala, an engineer at the University of Pennsylvania who coauthored a commentary on the study in the same issue of Science. The new ultralight insulator may be especially well suited to shielding components on spacecraft, which must endure extreme temperature swings when turning toward or away from the sun or re-entering Earth’s atmosphere, he says.

The aerogel comprises a network of tiny air pockets, with each pocket separated by two atomically thin layers of hexagonal boron nitride. Much like how double-pane windows prevent heat from escaping a house in winter, the double-pane ceramic barrier makes it difficult for heat to transfer from one air bubble to another. It’s also difficult for heat to spread through the material by traveling along the hexagonal boron nitride layers themselves, because that would require following long, circuitous routes, explains study coauthor Xiangfeng Duan, a chemist and materials scientist at the University of California, Los Angeles.

More:
https://www.sciencenews.org/article/new-insulation-material-weightless-durable-extreme-heat?tgt=nr