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If you channel water through a nanotube, you'll get a layer of water molecules frozen against the inside of the tube, but a chain of molecules in the middle will not freeze. It will continue to flow (well, move, anyway) even at temperatures down to eight degrees above absolute zero.

Research partners at MER Corp., Tucson, Ariz., supplied the nanotube samples made of nearly pure carbon only one atom thick. Each tube was 1.4 nanometers across and 10,000 nanometers long; imagine a piece of dry, hollow spaghetti 200 meters long because the nanotube is more than 7,000 times longer than wide. "With this one-dimensional confinement," Kolesnikov said, "we expected something new, but not the characteristics we observed. Something extraordinary appeared." What appeared was "totally different from bulk liquid or ice," said Kolesnikov. At 8 K, four-coordinated water molecules create an icy lining inside the naturally hydrophobic carbon nanotube. The lining free-floats inside the carbon nanotube with a 0.32 nanometer space all around it because that is as close as nature allows the water to the carbon. "An interior chain is running inside the lining, but compared to bulk water is much more mobile," Kolesnikov said. Researchers attribute the peculiarities to the low "coordination numbers" of the molecules. In liquid water, an average of 3.8 (the coordination number) hydrogen bonds connect the molecule to its closest neighbors. In ice, four hydrogen bonds connect to its closest neighbors. In nanotube water, the number of hydrogen bonds for the chain water molecules is only 1.86. "Because of the loose bonding, the water is very active and is always moving," Kolesnikov said. The icy lining is much more stable, but the mobile chain makes and breaks bonds continuously between parts of the chain and sometimes with the icy wall.