Properties Of Supercooled Water Research Articles

Specific properties of supercooled water in light of water anomalies

ABSTRACTWe review the effect of water anomalies on the properties of low-temperature water. When supercooled, liquids dynamical properties change drastically. Supercooled liquids undergo an at least exponential decrease of their diffusion coefficient when temperature decreases while their structure merely does not change. We discuss how that still unexplained change of dynamical properties at low temperatures affects water differently from other liquids and what can be deduced from it.

Overview: Nucleation of clathrate hydrates.

Molecular level knowledge of nucleation and growth of clathrate hydrates is of importance for advancing fundamental understanding on the nature of water and hydrophobic hydrate formers, and their interactions that result in the formation of ice-like solids at temperatures higher than the ice-point. The stochastic nature and the inability to probe the small length and time scales associated with the nucleation process make it very difficult to experimentally determine the molecular level changes that lead to the nucleation event. Conversely, for this reason, there have been increasing efforts to obtain this information using molecular simulations. Accurate knowledge of how and when hydrate structures nucleate will be tremendously beneficial for the development of sustainable hydrate management strategies in oil and gas flowlines, as well as for their application in energy storage and recovery, gas separation, carbon sequestration, seawater desalination, and refrigeration. This article reviews various aspects of hydrate nucleation. First, properties of supercooled water and ice nucleation are reviewed briefly due to their apparent similarity to hydrates. Hydrate nucleation is then reviewed starting from macroscopic observations as obtained from experiments in laboratories and operations in industries, followed by various hydrate nucleation hypotheses and hydrate nucleation driving force calculations based on the classical nucleation theory. Finally, molecular simulations on hydrate nucleation are discussed in detail followed by potential future research directions.

Escaping the no man's land: Recent experiments on metastable liquid water

The properties of supercooled water have been the subject of intense studies for decades. One of the main goals was to follow the evolution of water anomalies, already present in the stable liquid, as far as possible in the metastable phase. All anomalies were found to become more pronounced, but their origin has hitherto remained hidden because of crystallization into ice. We review the recent experimental developments in the field, with a focus on the techniques used to reach a larger metastability, or to extend the investigations to the negative pressure region of the phase diagram, where the liquid is also metastable with respect to its vapor.

Temperature Dependence of the Properties of Water and Its Solutes, Including the Supercooled Region

An earlier study on the properties of supercooled water and some solutes obtained by simple graphical extrapolation of data available in the literature, determined above the freezing point, led to the hypothesis that water could have a temperature of structural arrest at t0 =-30 °C for H2 O and -22 °C for D2 O. From the present investigation of many more properties of a widely varied nature, this discovery is confirmed throughout. The method is compared with the classical logarithmic Arrhenius and van't Hoff methods that predict t0 always to occur at 0 K, and with the more recently used power law dependence method. With the latter, extrapolated plots intersect the temperature axis at or near to a value of ts =-45 °C, that is, systematically more negative than t0 . It is argued that this ts value, which is the so-called singularity temperature, is likely to be an artefact. It is suggested that, instead of using modified van 't Hoff or Arrhenius relationships to describe temperature dependences in the full temperature range, polynomials in (t-t0 ) should be used.

Application of the two-liquid model for the interpretation of the observed electrophysical properties of supercooled water in nanopores

We propose a model combining the first-order liquid-liquid and the second-order ferroelectric phase transitions phenomenology to explain various features of the λ-point of liquid water. We suggest that the long-range dipole-dipole interaction of water molecules leads to a ferroelectric phase transition, which occurs only in the low-density component of the liquid and is the origin of the singularity of the dielectric constant recently observed in experiments with supercooled liquid water in nanoporous materials. Finally, we establish the model parameters and prove the consistency of the combined model by comparing its predictions with experimental data and the results of recent molecular-dynamics simulations.

Distinct Optical Properties of Supercooled Water and Ice Covering Dew-Point Hygrometer Mirror

The new optical method of supercooled water recognition in dew-point hygrometer is presented in this paper. The physical phenomenon of supercooled water and its influence on the hygrometer accuracy are described. A hypothesis relating to light scattering of water and ice layers is proposed. The new type of dew-point hygrometer based on the silicon mirror with the embedded capacitive detector and multisection optical detector is presented. Measurement data from the experimental hygrometer are provided

Analysis of the equations-of-state of water in the metastable region at high pressures

We analyze the existing equations-of-state of liquid water from the point of view of their applicability to equilibrium and nonequilibrium water–ice phase change problems that involve supercooled water. We show that the equation-of-state of Saul and Wagner [J. Phys. Chem. Ref. Data 18, 1537 (1989)] is most suitable for the description of thermodynamic properties of supercooled water in the range of pressures 0–200 kbar, and find the area of its validity in the metastable region.

The relative permittivity of supercooled water

Approximate relative permittivity data for water down to −35°C have been derived from measurements of the Maxwell–Wagner interfacial polarization which occurs at the surface of emulsified water droplets. Although the emulsifying agent strongly influences this polarization in a complex way, a novel method of data analysis enables the permittivity and conductivity to be obtained in a simple and direct manner. The derived data are in essential agreement with literature data near 0°C. To within an estimated experimental uncertainty of ±2% the present data conform to a critical exponent expression with the same critical temperature (228 K) found for many other properties of supercooled water, though the divergence is very weak.