To the strange nature of one of the seemingly simpler chemical compounds, water, a new rarity has just been added. American scientists have found thatwhen cooled below freezing, water can transform into a new type of liquid. Details appear in the magazineJournal of Physical Chemistry Bfrom the American Chemical Society (ACS).
According to Pradeep Kumar (University of Florida) and H. Eugene Stanley (Boston University), co-authors of the study, water is a foreign substance that showsmore than 80 unusual properties, including that it can exist in all three states of matter (solid, liquid or gas) at the same time. Or that the forces on its surface allow insects to walk on it and that this liquid rises from the roots to the leaves of the trees.
Now in addition, using computer simulations, Kumar and Stanley have shown that when liquid water freezes its tendency to conduct heat decreases, as is expected of an ordinary liquid. However, when the temperaturedrops to minus 54 degrees Celsius, the liquid water seems to start toconduct heat much better. Experiments suggest that, below this temperature, liquid water undergoes strong but constant structural changes, while the local structure of the liquid becomes extremely orderly, much like ice. These structural changes in liquid water result in increased heat conduction at lower temperatures. The researchers conclude that this surprising result supports the idea that water has a liquid-liquid phase transition.
