Limmer David T, Chandler David
Faraday Discuss. 2013;167:485-98. doi: 10.1039/c3fd00076a.
Water famously expands upon freezing, foreshadowed by a negative coefficient of expansion of the liquid at temperatures close to its freezing temperature. These behaviors, and many others, reflect the energetic preference for local tetrahedral arrangements of water molecules and entropic effects that oppose it. Here, we provide theoretical analysis of mesoscopic implications of this competition, both equilibrium and non-equilibrium, including mediation by interfaces. With general scaling arguments bolstered by simulation results, and with reduced units that elucidate corresponding states, we derive a phase diagram for bulk and confined water and water-like materials. For water itself, the corresponding states cover the temperature range of 150 K to 300 K and the pressure range of 1 bar to 2 kbar. In this regime, there are two reversible condensed phases - ice and liquid. Out of equilibrium, there is irreversible polyamorphism, i.e., more than one glass phase, reflecting dynamical arrest of coarsening ice. Temperature-time plots are derived to characterize time scales of the different phases and explain contrasting dynamical behaviors of different water-like systems.
众所周知,水在结冰时会膨胀,这在液态水在接近其冰点温度时具有负膨胀系数中已有所预示。这些行为以及许多其他行为,反映了水分子局部四面体排列的能量偏好以及与之相反的熵效应。在此,我们对这种竞争的介观影响进行理论分析,包括平衡态和非平衡态,以及界面的介导作用。通过模拟结果支持的一般标度论证,并使用阐明对应状态的简化单位,我们得出了大块水、受限水以及类水材料的相图。对于水本身,对应状态涵盖150 K至300 K的温度范围以及1巴至2千巴的压力范围。在这个范围内,有两个可逆的凝聚相——冰和液体。在非平衡态下,存在不可逆的多晶型现象,即不止一种玻璃相,这反映了粗化冰的动力学停滞。推导了温度 - 时间图以表征不同相的时间尺度,并解释不同类水系统的对比动力学行为。