Water glass

Water is an odd material, with its powerful solvation properties, its anomalous thermodynamic behavior, and the existence of its glassy states. Now, Austen Angell of Arizona State University has found an important clue as to what happens when water makes the transition from the crystalline ice phase to its glassy state. In so doing, he and his colleagues have also gained some useful insights into the behavior of liquid water. Writing in the February 1 issue of Science, Angell and his colleagues looked at both supercooled water and "nanoconfined" glassy ice to pinpoint the exact temperature at which the glass transition takes place. They found that water does not behave like other materials in forming a glassy phase. Instead of a characteristic heat-capacity jump, water's hydrogen-bond network makes water behave as if it were crystalline and it undergoes a order-disorder transition only its heat capacity has fallen to almost zero at 220 K.