This makes complete sense and leaves out the question of stickng it all together. Can we produce threads and then knit fabrics from this and all that?
My point is that carbon is our highest meltpoint element and a fiber layer can maximise insulation. What about glass? Produce a carbon fiber mat and soak in glass. When used the surface glass will simply blow off and heat gflow resistence will slow degradation.
Just a thought, but we can now produce something like that mat.
China’s new carbon nanotube insulation can resist temperatures exceeding 4,700°F
A breakthrough nanotube film stops solid, gas, and radiative heat transfer at thousands of degrees.Updated: Aug 30, 2025 11:08 AM EST
Representative image of a series of carbon nanotubes.
https://interestingengineering.com/science/carbon-nanotube-resist-extreme-temperatures
Ateam of Chinese researchers has reportedly developed a new carbon nanotube-based film that can resist temperatures up to 4,712°F (2,600°C). This new material could have important applications as a scalable insulation for aerospace, energy, or other high-temperature industries.
When things like spacecraft reenter Earth’s atmosphere, hypersonic planes fly, or reactors run at high temperatures, they face intense heat, often hotter than lava. Stopping this from happening is challenging, as most insulators fail at temperatures exceeding 2,732°F (1,500 °C).
Some materials are able to cope, but they often conduct too much heat in the process. At very high temperatures, radiation (heat carried by light/photons) becomes the biggest problem, and that’s the hardest to block.
So, researchers have for years attempted to develop a “dream” insulator that can stop conduction through solids, gases, and radiation. It also needs to survive extreme temperatures, while also being lightweight and stable.
To this end, researchers at Tsinghua University have allegedly engineered a new insulation material using super-aligned carbon nanotube films (SACNT-SF). To make this material, the team explains, they grow vertical carbon nanotube arrays.
Nanotubes: lightweight and strong insulator
With these in hand, they then “draw” thin sheets from them (like pulling silk). These films are stacked or wound into layers, resulting in an ultralight, porous, multilayered carbon nanotube structure.
This clever material, the team found, is able to attenuate all types of heat transfer. For conduction, the nanotubes are highly effective at conducting heat.
But here, heat has to travel across the layers, not along them. The tubes are only around 10–20 nm wide, with a lot of empty space, which means there is very little material for vibrations (phonons) to travel through.
When it comes to gas conduction, the pores are so tiny that gas molecules can’t easily move or collide inside (the Knudsen effect). Instead, molecules simply bounce around and lose energy, resulting in relatively weak conduction.
In terms of radiation, carbon nanotubes are excellent at absorbing and scattering infrared light. Their internal electronic structure (van Hove singularities) makes them interact strongly with thermal photons.
By stacking layers at different angles, radiation is trapped even more effectively. When studying the new material, the team found that it has a thermal conductivity of 0.004 W/mK at room temperature, or 0.03 W/mK at 4,712°F (2,600°C).
Important applications in industry
To put that in perspective, graphite felt (a common high-temperature insulator) has a thermal conductivity of 1.6 W/mK at the same temperature. This means the new material is significantly better.
The material is also very stable, with a recorded 5% degradation in performance after 310 cycles between room temperature and 3,632°F (2,000°C). It is also very light, with a density ranging from 5 to 100 kg/m³.
The nanotube material is also flexible and can wrap around irregular shapes. Scalable production of sheets up to 550 mm wide is also possible, with the potential to make sheets hundreds of meters long.
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