Phase diagram of water between hydrophobic surfaces

Abstract

Molecular dynamics simulations demonstrate that there are at least two classes of quasi-two-dimensional solid water into which liquid water confined between hydrophobic surfaces freezes spontaneously and whose hydrogen-bond networks are as fully connected as those of bulk ice. One of them is the monolayer ice and the other is the bilayer solid which takes either a crystalline or an amorphous form. Here we present the phase transformations among liquid, bilayer amorphous ͑or crystalline͒ ice, and monolayer ice phases at various thermodynamic conditions, then determine curves of melting, freezing, and solid-solid structural change on the isostress planes where temperature and intersurface distance are variable, and finally we propose a phase diagram of the confined water in the temperature-pressure-distance space.

Phase equilibria and interfacial tension of fluids confined in narrow pores

“…[8][9][10][11][12][13][14][15] In some cases, simulation reveals unexpected phase behavior of a confined fluid and then experiments confirm the results. 16,17 In molecular simulation one may deal with molecules in a portion of the pore alone, ignoring all the rest including molecules in a bulk phase in equilibrium with those in the pore, so that the computational cost is greatly reduced and thus a wider range of the thermodynamic space can be examined.…”

Multilayer Two-Dimensional Water Structure Confined in MoS2

“…[1][2][3][4][5][6][7][8][9][10][11] Inside a one-dimensional channel of carbon nanotubes, for example, water molecules could undergo unconventional phase transitions [12][13] and form ice-like structures at room temperatures depending on the channel diameter. Also, a delicate balance between entropy and enthalpy can render these confined water thermodynamically more stable than the bulk water.…”

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

“…3 These hydration layers also influence the chemical and mechanical properties of hydrophilic or hydrophobic surfaces such as oxides (silica, alumina, mica, clay, nano tubes, and graphite). 6,[19][20][21][22][29][30][31][32][33][34] Water is also a pervasive environmental component whose interactions with surfaces are critical to system performance in a wide range of emerging nano and other chemical and biological technologies.…”