The ice in carbon nanotubes does not melt at 150 degrees Celsius

Лед в углеродных нанотрубках не тает при 150 градусах Цельсия

. Physicists from MIT found that the water inside carbon nanotubes remains ice even at temperatures exceeding not only zero, but a hundred or even 150 degrees Celsius, according to a paper published in the journal Nature Nanotechnology.

“If you put the liquid in monopolist, then its phase behavior will greatly change. We expected that the melting point and the boiling point of water will change, but wasn’t ready to do with how much they move. When we go on such a microscopic level, all the old rules of physics can be thrown in the trash,” said Michael Strano (Michael Strano) from the Massachusetts Institute of technology in Boston (USA).

Strano and his colleagues have been examining the secrets of the device’s nanotubes and looking for unorthodox ways of their application in practice. For example, this year they showed that the incorporation of nanotubes into the leaves of plants makes them ultra-sensitive detectors of explosives, glowing with the appearance in the air of traces of their molecules and triples the efficiency of photosynthesis.

In his new work team Strano revealed another unusual feature of the nanotubes by observing the behavior of water molecules inside them. For this, the researchers filled these nanoconstructs water and “fired” them with an infrared laser, watching as the water molecules reflect these rays.

How to explain physics in a typical nanotube, whose diameter is from one to five nanometers, can “climb” a very small number of water molecules that greatly changes their physical properties and how they interact with each other and change their behavior when changing environment.

Frosting and defrosting nanotubes of different sizes, filled with water, Strano and his colleagues discovered a very surprising phenomenon was that the temperature of the freezing and melting of water has changed inside the nanotubes are much stronger than predicted by the theory.

For example, the ingress of water into the thickest of the nanotube diameter of 1.5 nanometer has led to the fact that the water remained ice-even at temperatures where water is liquid, usually from three to 30 degrees Celsius. Further reduction of the nanotubes led to even stronger changes in the temperature of melting ice when the contraction of 0.1 nanometer melting grew on average by 10-20 degrees.

Thanks to the water in the thinnest nanotubes, whose diameter was about a nanometer, melted at a temperature above the boiling point for plain water. She at least was 105 degrees Celsius, and a maximum of about 150 degrees Celsius.

As noted by the Strange, surprising is not only what water remains in the ice at such high temperatures, but also the fact that it was able to penetrate the thin nanotubes, which have, according to the theory, strongly to repel water and not to let her inside. Why this happens remains a mystery for American physicists.

Despite the lack of understanding of how they work, like nanotube, according to the scientist, have a lot of practical applications. For example, you can use them to as a kind of wires that transmit positive ions, and for the production of nanotube ice, not melting at room temperature.