Fig 11 - uploaded by Zhe Wang
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![? The average density of the confined D2O as a function of T at P = 0.1 kbar (black squares), 1 kbar (red circles), 2.5 kbar (heating scan, blue up triangles), 4 kbar (green down triangles) and 5 kbar (magenta left triangles). The left-hand-side region of the dashed vertical line is the two-phase region with its phase separation between 3 and 4 kbar. The right-hand side region of the dotted vertical line is the one-phase region. Adapted from [30].](profile/Zhe-Wang-102/publication/309735506/figure/fig8/AS:425848860876807@1478541688578/The-average-density-of-the-confined-D2O-as-a-function-of-T-at-P-01-kbar-black.png)
? The average density of the confined D2O as a function of T at P = 0.1 kbar (black squares), 1 kbar (red circles), 2.5 kbar (heating scan, blue up triangles), 4 kbar (green down triangles) and 5 kbar (magenta left triangles). The left-hand-side region of the dashed vertical line is the two-phase region with its phase separation between 3 and 4 kbar. The right-hand side region of the dotted vertical line is the one-phase region. Adapted from [30].
Source publication
In this paper we present a review on our recent experimental investigations into the phase behavior of the deeply cooled water confined in a nanoporous silica material, MCM-41, with elastic neutron scattering technique. Under such strong confinement, the homogeneous nucleation process of water is avoided, which allows the confined water to keep its...
Contexts in source publication
Context 1
... to examine the obtained phase diagram and to get a general idea on how the density of the confined water behaves as a function of T and P , we perform isobaric density measurements on the confined D 2 O at 5 pressures: 0.1 kbar, 1 kbar, 2.5 kbar, 4 kbar and 5 kbar. The data at 2.5 kbar are measured with warming scan. The results are shown in fig. 11. According to the phase diagram shown in fig. 10, below ∼190 k, the former 3 pressures are in the LDL phase, while the last 2 pressures are in the HDL phase. Figure 11 clearly shows that below 190 K, there is an evident density gap of ∼0.04 g/cm 3 between the density profiles at 0.1 kbar, 1 kbar, 2.5 kbar and the density profile at 4 ...
Context 2
... to the phase diagram shown in fig. 10, below ∼190 k, the former 3 pressures are in the LDL phase, while the last 2 pressures are in the HDL phase. Figure 11 clearly shows that below 190 K, there is an evident density gap of ∼0.04 g/cm 3 between the density profiles at 0.1 kbar, 1 kbar, 2.5 kbar and the density profile at 4 kbar. This gap shows the phase separation between LDL and HDL. ...
Citations
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, we introduce a coarse-grained model introduced by Franzese and Stanley (FS) that accounts for the many-body interactions of water. We review mean-field calculations and Monte Carlo simulations on water monolayers for a wide range of pressures and temperatures, including extreme conditions. The results show the presence of two dynamic crossovers and explain the origin of diffusion anomalies. Moreover, the model shows that all the different scenarios, proposed in the last decades as alternative explanations of the experimental anomalies of water, can be related by the fine-tuning of the many-body (cooperative) interaction. Once this parameter is set from the experiments, the FS model predicts a phase transition between two liquids with different densities and energies in the supercooled water region, ending in a liquid-liquid critical point. From this critical point stems a liquid-liquid Widom line, i.e., the locus of maxima of the water correlation length, that in the FS model can be directly calculated. The results are consistent with the extrapolations from experiments. Furthermore, they agree with those from atomistic models but make predictions over a much wider thermodynamic region, allowing for a better interpretation of the available experimental data. All these findings provide a coherent picture of the properties of water and confirm the validity of the FS model that has proved to be useful for large-scale simulations of biological systems.
