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Understanding the phase behaviors of nanoconfined water has driven notable research interests recently. In this work, we examine the structures and thermodynamics of water encapsulated under a graphene cover. We find layered water structures up to ~1000 molecules, which is stabilized by the spatial confinement and pressure induced by the adhesion between graphene cover and substrate. For monolayer encapsulations, we identify both crystalline lattices and defects. Free energy analysis shows that these low- entropy orders are compensated by high formation energies. There exists an order- disorder transition for this condensed phase at ~480-490 K, with a sharp reduction in the number of hydrogen bonds and increase in the entropy. These findings offer fundamental understandings of the encapsulated water, and provide guidance for practical applications with its presence, for example, in the design of nanoelectronic devices.
We evaluate the grand potential of a cluster of two molecular species, equivalent to its free energy of formation from a binary vapour phase, using a nonequilibrium molecular dynamics technique where guide particles, each tethered to a molecule by a
Deeply supercooled water exhibits complex dynamics with large density fluctuations, ice coarsening and characteristic time scales extending from picoseconds to milliseconds. Here, we discuss implications of these time scales as they pertain to two-ph
Using concepts from perturbation and local molecular field theories of liquids we divide the potential of the SPC/E water model into short and long ranged parts. The short ranged parts define a minimal reference network model that captures very well
Water modeling is a challenging problem. Its anomalies are difficult to reproduce, promoting the proliferation of a large number of computational models, among which researchers select the most appropriate for the property they study. In this chapter
The free energetics of water density fluctuations near a surface, and the rare low-density fluctuations in particular, serve as reliable indicators of surface hydrophobicity; the easier it is to displace the interfacial waters, the more hydrophobic t