“Inside tiny tubes, water turns solid when it should be boiling,” announced the headline atop the most-viewed MIT News story in November 2016. The story’s popularity underlines that basic research can reveal fascinating surprises about the most familiar phenomena in nature.
The tiny vessels described by the headline are carbon nanotubes, whose inner dimensions are not much bigger than a few water molecules—mere billionths of a meter—and which are typically expected to repel rather than take in fluid. Within the tubes, MIT researchers observed the molecules entering a ice-like, stiff phase rather than the liquid or vapor that would be expected at the high temperatures employed. The team, led by led by Michael Strano, MIT’s Carbon P. Dubbs Professor in Chemical Engineering, used a technique called vibrational spectroscopy to track with unprecedented precision the movement of the water molecules inside the nanotubes.
According to MIT News, “The finding might lead to new applications—such as, essentially, ice-filled wires—that take advantage of the unique electrical and thermal properties of ice while remaining stable at room temperature.” Or, as Strano puts it, “All bets are off when you get really small.”