Monolayer Ice

Abstract

We report results from molecular dynamics simulations of water under confinement and at ambient conditions that predict a first-order freezing transition from a monolayer of liquid water to a monolayer of ice induced by increasing the distance between the confining parallel plates. Since a slab geometry is incompatible with a tetrahedral arrangement of the sp(3) hybridized oxygen of water, the freezing is coupled to a linear buckling transition. By exploiting the ordered out-of-plane displacement of the molecules in the buckled phase the distortion of the hydrogen bonds is minimized.

Phase diagram of water between hydrophobic surfaces

“…24 As mentioned earlier the monolayer ice has been obtained from the TIP5P water. 16 The LJ 9-3 potential for the water-wall interaction ignores any atomic structure of the walls, but it was confirmed from our earlier simulations that a potential function representing structure of hydrophobic surfaces gives rise to the same structure of the bilayer ice. ͑Note in the case the normal pressure is fixed.͒ Therefore, the results presented below would not be qualitatively altered by use of other reasonable potential models for water and hydrophobic surfaces.…”

“…15 More recently spontaneous formation of a monolayer ice was found by molecular dynamics ͑MD͒ simulations of the TIP5P model water. 16 Quasi-one-dimensional water, too, exhibits phase transitions qualitatively different from those of the bulk water. The first evidence for such transitions was again obtained from MD simulations combined with free-energy calculations: the simulations demonstrated that water inside a carbon nanotube freezes into four different forms of the ice nanotube, a class of quasi-one-dimensional crystalline ices.…”

“…For the monolayer ice, which has additional restrictions on the proton arrangement, Pauling's method gives rise to a "negative" residual entropy: k ln W with W Ͻ 1, which is irrational. 16 But because of the additional restrictions one can count W exactly with no effort as given in Eq. ͑18͒.…”

Multilayer Two-Dimensional Water Structure Confined in MoS2

“…3,[14][15] Theoretical investigations of the structures of the two-dimensional (2D) water confined in between the flat walls have suggested puckered rhombic monolayer ice, planar hexagonal, or amorphous phases depending on the conditions and models employed in the simulations. [16][17][18][19][20][21][22][23][24][25][26][27][28][29] Although the structures of confined water have been predicted for a variety of dimensions and materials using molecular dynamics (MD) simulations, the first experimental observation of the 2D water in between the two graphene sheets was obtained very recently using high-resolution transmission electron microscopy measurements (TEM). 30 This observation revealed the formation of a monolayer of planar "square" ice with a high packing density and, depending on the inter-graphene distance, the formation of bi-and trilayer crystallites of water.…”

Direct observation of self-assembled chain-like water structures in a nanoscopic water meniscus

“…These phenomena include assembly and function of biomolecules, [1][2][3] wetting and interfacial interactions, [4][5][6] corrosion processes, 7,8 condensation and crystallization of water vapor on surfaces, 3,[8][9][10][11][12][13] and amorphous solid water in an interstellar medium. 14 It has long been postulated that water in confined spaces can have dramatically different physical properties from bulk water in extended spaces.…”