Angell C Austen
Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA.
Science. 2008 Feb 1;319(5863):582-7. doi: 10.1126/science.1131939.
The vitrification of pure water is compared with that of molecular solutions rich in water, and gross differences are noted. Thermodynamic reasoning and direct observations on noncrystallizing nanoconfined water indicate that the glass transition in ambient-pressure water is qualitatively distinct from that found in the usual molecular liquids. It belongs instead to the order-disorder class of transition seen in molecular and ionic crystalline materials. The distinctive "folding funnel" energy landscape for this type of system explains the extreme weakness of the glass transition of water as well as the consequent confusion that has characterized its scientific history; it also explains the very small excess entropy at the glass transition temperature. The relation of confined water behavior to that of bulk is discussed, and the "fragile-to-strong" transition for supercooled water is interpreted by adding a "critical point-free" scenario to the two competing scenarios for understanding supercooled bulk water.
将纯水的玻璃化与富含水的分子溶液的玻璃化进行了比较，并注意到了显著差异。热力学推理以及对不结晶的纳米受限水的直接观察表明，常压下水的玻璃化转变在性质上与普通分子液体中的玻璃化转变不同。相反，它属于分子和离子晶体材料中出现的有序-无序转变类别。这种类型系统独特的“折叠漏斗”能量景观解释了水的玻璃化转变极其微弱的原因，以及其科学史上随之而来的混乱；它还解释了玻璃化转变温度下非常小的过量熵。讨论了受限水行为与本体水行为的关系，并通过在理解过冷本体水的两种竞争情景中加入“无临界点”情景，对过冷水的“从脆性到刚性”转变进行了解释。
