May 21, 2015

How supercooled water is prevented from turning into ice

(May 21, 2015)  Calculating the energy barrier that keeps liquid water below zero from immediately turning into ice provides the key to understanding its ability to be compressed as temperature drops

Water behaves in mysterious ways. Especially below zero, where it is dubbed supercooled water, before it turns into ice. Physicists have recently observed the spontaneous first steps of the ice formation process, as tiny crystal clusters as small as 15 molecules start to exhibit the recognisable structural pattern of crystalline ice. This is part of a new study, which shows that liquid water does not become completely unstable as it becomes supercooled, prior to turning into ice crystals. The team reached this conclusion by proving that an energy barrier for crystal formation exists throughout the region in which supercooled water’s compressibility continues to rise. Previous work argued that this barrier vanished as the liquid gets colder. These findings have been published in EPJ E by Connor Buhariwalla from St. Francis Xavier University in Antigonish, Canada and colleagues.

image >>