New Hexagonal-rhombic Trilayer Ice Structure Confined between Hydrophobic Plates
New Hexagonal-rhombic Trilayer Ice Structure Confined between Hydrophobic Plates
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DOI：
10.1063/1674-0068/27/01/15-19
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发表时间：
2014-03
影响因子：
1
通讯作者：
Min Jia;Wenhui Zhao;Lan-feng Yuan
中科院分区：
文献类型：
--
作者：
Min Jia;Wenhui Zhao;Lan-feng Yuan
我们进行分子动力学模拟的水限制在两个光滑的疏水壁，并观察到两个晶体结构，其中一个被首次报道。这两种结构都遵循冰规则。新的冰相是一个扁平的六边形-菱形三层冰，在1 GPa的负载下，在1.0 nm的壁间距。在这种结构中，水分子在两个层旁边的一个壁（外层）和中间层形成六边形环和菱形环，分别。对于外层的分子，其四个氢键中的三个在同一层中，另一个氢键连接到中间层。对于中间层的分子，其四个氢键中只有两个位于同一层，另外两个连接到两个不同的外层。尽管它们的图案不同，但三层的面积密度几乎相等。另一种结构是在100 MPa的侧向压力下以0.8 nm的壁间距产生的扁平六边形双层冰，类似于古贺等人[Phys. Rev. Lett. 79，5262（1997）]。一阶和连续相变发生在这些模拟。
We perform molecular dynamics simulations for water confined between two smooth hydrophobic walls and observe two crystalline structures with one being first reported. Both of these structures obey the ice rule. The novel ice phase is a flat hexagonal-rhombic trilayer ice, obtained under 1 GPa load at wall separation of 1.0 nm. In this structure, the water molecules in the two layers next to one of the walls (outer layers) and in the middle layer form hexagonal rings and rhombic rings, respectively. For a molecule in the outer layers, three of its four hydrogen bonds are in the same layer, and the other one hydrogen bond connects to the middle layer. For a molecule in the middle layer, only two of its four hydrogen-bonds are located in the same layer, and the other two connect to two different outer layers. Despite their different motifs, the area densities of the three layers are almost equal. The other structure is a flat hexagonal bilayer ice produced at wall separation of 0.8 nm under lateral pressure of 100 MPa, analogous to a system demonstrated by Koga et al. [Phys. Rev. Lett. 79, 5262 (1997)]. Both first-order and continuous phase transitions take place in these simulations.