Boron Nitride Nanotubes potential material for future hypersonic planes

Boron nitride nanotubes could be used to make hypersonic planes.

NASA has one of the few facilities in the world able to produce quality Boron Nitride Nanotubes BNNTs. Carbon nanotubes can stay stable at temperatures up to 400 degrees Celsius but BNNTs can withstand up to 900 degrees Celsius. BNNTs are also able to handle high amounts of stress and are extremely lightweight.

While the study has brought new light to the strength and stability of BNNTs, their use on planes may not be a reality for another five to 10 years. “Right now, BNNTs cost about $1,000 per gram. It would be impractical to use a product that expensive,” said Ke. But, that does not mean it will never happen. Carbon nanotubes were about the same price 20 years ago. As more studies indicated the usefulness of carbon nanotubes, the production rates increased and prices went down to the current rate, between $10 and $20 per gram. Ke sees the same fate coming down the line for BNNTs.

Ke plans to continue this type of research on BNNTs. He has worked with the U.S. Air Force on several research projects and in 2010 was chosen for the U.S. Air Force’s Young Investigator Research Program, a prestigious program with fewer than 20 percent of applicants accepted. While the advances of BNNTs will probably be used first in fighter jets, Ke said he can see this type of technology trickling down to commercial flights. In 10 to 20 years, air travel could be drastically different from what we experience today.

Scientific Reports – Quantitative Characterization of Structural and Mechanical Properties of Boron Nitride Nanotubes in High Temperature Environments

Abstract

The structural stability and mechanical integrity of boron nitride nanotubes (BNNTs) in high temperature environments are of importance in pursuit of their applications that are involved with extreme thermal processing and/or working conditions, but remain not well understood. In this paper, we perform an extensive study of the impacts of high temperature exposure on the structural and mechanical properties of BNNTs with a full structural size spectrum from nano- to micro- to macro-scale by using a variety of in situ and ex situ material characterization techniques. Atomic force microscopy (AFM) and high resolution transmission electron microscopy measurements reveal that the structures of individual BNNTs can survive at up to 850 °C in air and capture the signs of their structural degradation at 900 °C or above. In situ Raman spectroscopy measurements reveal that the BN bonds in BNNT micro-fibrils undergo substantial softening at elevated temperatures of up to 900 °C. The AFM-based nanomechanical compression measurements demonstrate that the mechanical integrity of individual BNNTs remain intact after being thermally baked at up to 850 °C in air. The studies reveal that BNNTs are structurally and mechanically stable materials in high temperature environments, which enables their usages in high temperature applications.

Conclusion

In this paper, the impacts of high temperature exposure on the structural and mechanical properties of BNNTs were investigated by using a variety of in situ and ex situ material characterization techniques. In situ Raman and optical spectroscopy measurements reveal that BNNT micro fibrils can largely survive at temperatures of up to 1000 °C in air even with substantial thermal-induced BN bond strength weakening. AFM and HRTEM imaging measurements reveal that the structures of individual BNNTs can survive at temperatures of up to 850 °C in air, and also capture the signs of their structural degradation at 900 °C or above. The AFM-based nanomechanical compression measurements demonstrate that the mechanical integrity of individual BNNTs remain intact after being thermally annealed at up to 850 °C in air. The findings are useful to better understand the structural stability and mechanical integrity of BNNTs, especially in the pursuit of their high temperature applications

10 thoughts on “Boron Nitride Nanotubes potential material for future hypersonic planes”

  1. Hex Boron Nitride single layer sheet has pores suitable for hydrogen ion passage. Multiple layers grown, the N and B locations rotate 60 degree relative to the previous layer, centered upon the pore’s axis. The pores of the individual sheets remain aligned.

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  2. For a variation of the self destruction explanation of the Fermi Paradox:
    I’m part way through read “Directive 51” by John Barnes. The plot involves some anti-technology types having a few people who know enough biotech/nanotech to make stuff that will eat plastics & wreck electrical machinery. They either don’t think things through or don’t care that that will kill billions.

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  3. Boron Nitride nanotubes are superior to Carbon Nanotubes in some ways. That -B-N- unit is polar compared to the C-C sp2 bond. Also the stuff doesn’t burn so easily in oxygen, the way that carbon does. I remember one of the ways to make the BNNTs was through ball-milling, but there’s also a laser method too.

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  4. Ke said he can see this type of technology trickling down to commercial flights. In 10 to 20 years, air travel could be drastically different from what we experience today.

    Perhaps so. But the number one drastic improvement for air travel could be done right now without any new tech at all: stop squeezing seat widths & knee room.

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    • One might as well ask them to stop making money…the amount of travel that is price AND time flexible is probably well below 1%. the goal of the airlines is to keep planes full and the costs saved by cramming 1 plane vs buying 2 that only get half filled are enormous. Best we all forget that air travel was every luxuriant or comfortable. it will continue to be less so as that is where the market is going.

      that said… ***OFF TOPIC DISCLAIMER*** the GIANT robot fight between the US and JAPAN is on tonight on twitch at 7pm Pacific time. on youtube and somewhere else later.

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  5. It seems more and more certain to me that either the Reapers are due any day now (the best explanation of Fermi’s paradox) or WE are the Progenitors, WE are the Old Ones (happiest and next best explanation of Fermi’s Paradox).

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    • You don’t like the zoo hypothesis? (More politely called the Prime Directive theory. ie. The aliens that have found us are operating on look-don’t-touch.)

      Or the techno-rapture hypothesis. That once you get enough computing power you just retreat into a ball of computronium and the idea of being even 1 light second away from instant communication with the 5 trillion other members of your civilization becomes unbearable. Likewise, with thought running at microsecond, then nanosecond, then femptosecond timescales, the effective distance between the stars grows larger and larger.

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    • It seems more and more certain to me that either the Reapers are due any day now (the best explanation of Fermi’s paradox) or WE are the Progenitors, WE are the Old Ones (happiest and next best explanation of Fermi’s Paradox).

      there’s the SAI idea. You live in digital. And the custom universe idea. Soon as you reach KII-III you basically build a custom universe and retreat to it, so there are no space interstellar faring civilizations left in “the natural universe”. Or that self destruction is pretty inevitable.

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