Kohl Ingrid, Bachmann Luis, Mayer Erwin, Hallbrucker Andreas, Loerting Thomas
Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, 6020 Innsbruck, Austria.
Nature. 2005 May 26;435(7041):E1; discussion E1-2. doi: 10.1038/nature03707.
It has been unclear whether amorphous glassy water heated to around 140-150 K remains glassy until it crystallizes or whether instead it turns into a supercooled and very viscous liquid. Yue and Angell compare the behaviour of glassy water under these conditions to that of hyperquenched inorganic glasses, and claim that water stays glassy as it heats up to its crystallization point; they also find a 'hidden' glass-to-liquid transition at about 169 K. Here we use differential scanning calorimetry (DSC) heating to show that hyperquenched water deposited at 140 K behaves as an ultraviscous liquid, the limiting structure of which depends on the cooling rate--as predicted by theoretical analysis of the liquid-to-glass transition. Our findings are consistent with a glass-to-liquid transition-onset temperature (T(g)) in the region of 136 K (refs 3,4), and they indicate that measurements of the liquid's properties may clarify the anomalous properties of supercooled water.
加热到约140 - 150K的无定形玻璃态水，在结晶之前是否一直保持玻璃态，或者是否会转变成过冷且粘性极大的液体，这一点一直都不明确。Yue和Angell将这些条件下玻璃态水的行为与超急冷无机玻璃的行为进行了比较，并声称水在加热到其结晶点时仍保持玻璃态；他们还在约169K处发现了一个“隐藏”的玻璃态到液态的转变。在此，我们使用差示扫描量热法（DSC）加热来表明，沉积在140K的超急冷水表现为一种超粘性液体，其极限结构取决于冷却速率——这正如液 - 玻璃转变的理论分析所预测的那样。我们的研究结果与玻璃态到液态转变起始温度（T(g)）在136K左右（参考文献3,4）相符，并且表明对该液体性质的测量可能会阐明过冷水的异常性质。
