麻豆淫院

Chinese researchers have developed a new carbon nanotube insulator that can withstand high temperatures up to 2,600掳C, outperforming all other materials used for extreme-temperature applications. This breakthrough could be used for heat shields on hypersonic vehicles and spacecraft during re-entry into the atmosphere and in other high-temperature environments.

Spacecraft, jet engines and industrial furnaces need materials that can handle heat without melting, cracking or letting heat out. However, high-temperature thermal insulation materials (TIMs) have major drawbacks. They either fail at temperatures above 1,500掳C or are not very effective at stopping the heat from passing through. This means that to achieve a decent amount of insulation, you have to use more material, which adds bulk and weight.

That's why scientists are searching for new, advanced materials that can effectively block heat while also being thin and lightweight. In a paper in Advanced Functional Materials, researchers at Tsinghua University describe how they stacked and wound together very thin, flexible films of carbon nanotubes to create a new insulation material called super-aligned carbon nanotube films (SACNT-SF). This revolutionary material blocks heat more effectively than any other known insulator at high temperatures.

"SACNT-SF exhibits an effective thermal conductivity of 0.004 W m^鈭�1 K^鈭�1 at room temperature and 0.03 W m^鈭�1 K^鈭�1 at 2,600掳C, outperforming all TIMs reported to date," the researchers wrote in their paper.

SACNT-SF's insulation property is due to a combination of factors. The stacked nanotubes are mostly space, so there isn't a lot of solid material for heat to travel through. And the gaps between them are so tiny that they block the movement of gas molecules, preventing them from transferring heat.

In addition to its superior insulation, SACNT-SF is also remarkably durable. It can withstand repeated heating and cooling cycles and remains stable up to 3,000掳C in an argon atmosphere. And unlike bulky insulation material, this innovative substance is made of paper-thin films that can easily bend around a variety of shapes.

There is a lot of excitement about SACNT-SF and its many potential uses. For example, it could be used to create better heat shields for spacecraft and hypersonic vehicles, and it could improve the efficiency of extremely hot furnaces and reactors. Because it's thin and flexible, it could also be wrapped around complex electronic components to protect them from heat.

The next challenge

However, one significant drawback of this new carbon nanotube insulator is that it oxidizes above 500掳C in air. This means it cannot be used in unprotected environments with oxygen at elevated temperatures, as it would burn away.

So, the research team plans to add protective coatings that will enable it to operate in settings where oxygen is present at high temperatures, such as jet engines.