Bilayer ice and alternate liquid phases of confined water
Bilayer ice and alternate liquid phases of confined water
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DOI：
10.1063/1.1580101
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发表时间：
2003-07-15
影响因子：
4.4
通讯作者：
Mark, AE
中科院分区：
文献类型：
--
作者：
Zangi, R;Mark, AE
我们报告的结果从分子动力学模拟的冻结和融化，在环境温度下（T=300 K），液态水的双层引起的要么改变两个限制平行壁之间的距离在恒定的侧压力或横向压缩在恒定的板分离。这两个转变被发现是一阶。研究的系统由1200个水分子组成，由TIP 5 P模型描述。发现冰双层中氧原子的面内对称性是菱形的，具有扭曲的配准排列。在冰双层的稳定区域的上方和下方，我们观察到两个双层相的液态水，其在最近邻的第二壳的水平处的局部排序和垂直于平面的密度分布中不同，产生具有不同密度的两个液相。这些结果表明，一个有趣的可能性的液-液转变的水，局限于一个双层，在该地区的冰双层是不稳定的，相对于任何一个液相。此外，我们发现，在相同条件下，限制在3-8层的水仍处于液相（尽管横向密度分布分层），侧向扩散系数值与本体相当。(C)2003年，美国物理学会。
We report results from molecular dynamics simulations of the freezing and melting, at ambient temperature (T=300 K), of a bilayer of liquid water induced by either changing the distance between two confining parallel walls at constant lateral pressure or by lateral compression at constant plate separation. Both transitions are found to be first order. The system studied consisted of 1200 water molecules that were described by the TIP5P model. The in-plane symmetry of the oxygen atoms in the ice bilayer was found to be rhombic with a distorted in-registry arrangement. Above and below the stability region of the ice bilayer we observed two bilayer phases of liquid water that differ in the local ordering at the level of the second shell of nearest neighbors and in the density profile normal to the plane, yielding two liquid phases with different densities. These results suggest the intriguing possibility of a liquid-liquid transition of water, confined to a bilayer, at regions where the ice bilayer is unstable with respect to either of the liquid phases. In addition, we find that under the same conditions, water confined to 3-8 layers remains in the liquid phase (albeit stratification of the transverse density profile) with values of the lateral diffusion coefficient comparable to that of the bulk. (C) 2003 American Institute of Physics.