Ice Nucleation In Water Research Articles

Anomalous Vapor and Ice Nucleation in Water at Negative Pressures: A Classical Density Functional Theory Study.

In contrast to the abundance of work on the anomalous behavior of water, the relationship between the water's thermodynamic anomalies and kinetics of phase transition from metastable water is relatively unexplored. In this work, we have employed classical density functional theory to provide a unified and coherent picture of nucleation (both vapor and ice) from metastable water at negative pressure conditions. Our results suggest a peculiar nonmonotonic temperature dependence of vapor-liquid surface tension at temperatures where vapor-liquid coexistence is metastable with respect to the ice phase. The vapor nucleation barrier on isochoric cooling also shows a nonmonotonic temperature dependence. We further report that, for low density isochores, the temperature of the minimum vapor nucleation barrier does not coincide with the temperature of maximum density (TMD) where metastability is maximum. The difference between the and the TMD, however, decreases with increasing the density of the isochore. The vapor nucleation barrier along isobars shows an interesting crossover behavior in the vicinity of the Widom line on lowering the temperature. Our results on the ice nucleation suggest an anomalous retracing behavior of the nucleation barrier along isotherms at negative pressures and theoretically validate the recent findings that the reentrant ice(Ih)-liquid coexistence line can induce a drastic change in the kinetics of ice nucleation. Thus, this study establishes a direct connection between the metastable water's thermodynamic anomalies and the (vapor and ice) nucleation kinetics. In addition, this study provides deeper insights into the origin of the isothermal compressibility maximum on isochoric cooling.

Effects of an oscillating magnetic field on ice nucleation in aqueous iron‐oxide nanoparticle dispersions during supercooling and preservation of beef as a food application

AbstractThis study was aimed to explore the effects of an oscillating magnetic field (OMF) on the ice nucleation behavior of distilled water (DW) and iron‐oxide nanoparticle dispersion (IND) during supercooling. The magnetic field intensity and distribution of the OMF produced by Helmholtz coils were predicted using COMSOL. It was hypothesized that the ferric nanoparticles in the IND would promote the heterogeneous ice nucleation, and the OMF could inhibit the nucleation process by rotating the particles. The supercooling probability of IND was significantly increased by 36% under the OMF at the ambient temperature of −10°C. However, the OMF also enhanced the supercooling stability of DW by 32%, suggesting that it could induce the dipolar movements of water molecules via water diamagnetism and create the induced electric fields, subsequently suppressing the occurrence of ice nucleation within DW as well. As an extended application, fresh beef was preserved in a supercooled state with the OMF treatment and its supercooled state was effectively extended for a week at the temperature of −4°C. The supercooling preservation potentially prolonged the shelf life of meat with no significant changes in drip loss, color, and bacterial growth for up to a week in this study.Practical applicationsRecently, the application of an oscillating magnetic field (OMF) has attracted considerable interest in the food preservation industry because the OMF is supposed to control ice nucleation during the freezing process. The present study demonstrated that the OMF treatment potentially suppressed ice nucleation in water and aqueous iron‐oxide nanoparticle dispersion. As a case study, beef steaks were preserved at subzero temperatures with the OMF treatment and they were successfully supercooled at −4°C for up to 7 days. The supercooling technology based on the OMF allowed to maintain the meat quality for an extended period while preventing bacterial growth. This novel technology can be integrated into a commercial refrigeration system and ensure the prolonged shelf life of various food products.

Development of Corn-Oil Ester and Water Mixture Phase Change Materials for Food Refrigeration Applications

This research aims to investigate development of corn-oil ester and water mixtures as novel solid-liquid phase change material candidates for chilled and frozen food refrigeration applications. Thermal properties of both water and its mixture with corn-oil ester were tested by DSC and T-history methods. The results showed that corn oil could mix well in water solutions. Phase transition temperatures of the mixtures were lower than those of individual water. Corn-oil ester in the mixtures was acted as a nucleate agent and it was able to lower freezing point and to trigger ice nucleation in water which could diminish super-cooling. Addition of corn oil ester by 5% to 35% in water solutions could decrease freezing temperature from 0°C down to respectively -3.5°C to -28°C. The PCM candidates were also found to have excellent thermal properties that could fulfill requirements of thermal energy storage systems for food refrigeration applications.

High-speed imaging of ice nucleation in water proves the existence of active sites.

Understanding how surfaces direct nucleation is a complex problem that limits our ability to predict and control crystal formation. We here address this challenge using high-speed imaging to identify and quantify the sites at which ice nucleates in water droplets on the two natural cleavage faces of macroscopic feldspar substrates. Our data show that ice nucleation only occurs at a few locations, all of which are associated with micron-size surface pits. Similar behavior is observed on α-quartz substrates that lack cleavage planes. These results demonstrate that substrate heterogeneities are the salient factor in promoting nucleation and therefore prove the existence of active sites. We also provide strong evidence that the activity of these sites derives from a combination of surface chemistry and nanoscale topography. Our results have implications for the nucleation of many materials and suggest new strategies for promoting or inhibiting nucleation across a wide range of applications.

Controlled ice nucleation using freeze-dried Pseudomonas syringae encapsulated in alginate beads

The control of ice nucleation is of fundamental significance in many process technologies related to food and pharmaceutical science and cryobiology. Mechanical perturbation, electromagnetic fields and ice-nucleating agents (INAs) have been known to induce ice nucleation in a controlled manner. But these ice-nucleating methods may suffer from cumbersome manual operations, safety concerns of external fields, and biocompatibility and recovery issues of INA particles, especially when used in living systems. Given the automatic ice-seeding nature of INAs, a promising solution to overcome some of the above limitations is to engineer a biocomposite that accommodates the INA particles but minimizes their interactions with biologics, as well as enabling the recovery of used particles. In this study, freeze-dried Pseudomonas syringae, a model ice-nucleating agent, was encapsulated into microliter-sized alginate beads. We evaluated the performance of the bacterial hydrogel beads to initiate ice nucleation in water and aqueous glycerol solution by investigating factors including the size and number of the beads and the local concentration of INA particles. In the aqueous sample of a fixed volume, the total mass of the INA particles (m) was found to be the governing parameter that is solely responsible for determining the ice nucleation performance of the bacterial hydrogel beads. The freezing temperature has a strong positive linear correlation with log10m. The findings in this study provide an effective, predictable approach to control ice nucleation, which can improve the outcome and standardization of many ice-assisted process technologies.

A physically constrained classical description of the homogeneous nucleation of ice in water.

Liquid water can persist in a supercooled state to below 238 K in the Earth's atmosphere, a temperature range where homogeneous nucleation becomes increasingly probable. However, the rate of homogeneous ice nucleation in supercooled water is poorly constrained, in part, because supercooled water eludes experimental scrutiny in the region of the homogeneous nucleation regime where it can exist only fleetingly. Here we present a new parameterization of the rate of homogeneous ice nucleation based on classical nucleation theory. In our approach, we constrain the key terms in classical theory, i.e., the diffusion activation energy and the ice-liquid interfacial energy, with physically consistent parameterizations of the pertinent quantities. The diffusion activation energy is related to the translational self-diffusion coefficient of water for which we assess a range of descriptions and conclude that the most physically consistent fit is provided by a power law. The other key term is the interfacial energy between the ice embryo and supercooled water whose temperature dependence we constrain using the Turnbull correlation, which relates the interfacial energy to the difference in enthalpy between the solid and liquid phases. The only adjustable parameter in our model is the absolute value of the interfacial energy at one reference temperature. That value is determined by fitting this classical model to a selection of laboratory homogeneous ice nucleation data sets between 233.6 K and 238.5 K. On extrapolation to temperatures below 233 K, into a range not accessible to standard techniques, we predict that the homogeneous nucleation rate peaks between about 227 and 231 K at a maximum nucleation rate many orders of magnitude lower than previous parameterizations suggest. This extrapolation to temperatures below 233 K is consistent with the most recent measurement of the ice nucleation rate in micrometer-sized droplets at temperatures of 227-232 K on very short time scales using an X-ray laser technique. In summary, we present a new physically constrained parameterization for homogeneous ice nucleation which is consistent with the latest literature nucleation data and our physical understanding of the properties of supercooled water.

Water ice nucleation characteristics of JSC Mars-1 regolith simulant under simulated Martian atmospheric conditions

[1] Water ice clouds in the Martian atmosphere are governed by parameters such as number density and particle size distribution that in turn affect how they influence the climate. With some of the underlying properties of cloud formation well known only for Earth, extrapolations to Mars are potentially misleading. We report here continued laboratory experiments to identify critical onset conditions for water ice formation under Martian cloud forming temperatures and water partial pressures (155–182 K, 7.6 × 10−5 to 7.7 × 10−3 Pa H2O). By observing the 3 μm infrared band to monitor nucleation and growth, we observe significant temperature dependence in the nucleation of ice on JSC Mars-1 regolith simulant, with critical saturation ratios, Scrit, as high as 3.8 at 155 K. At temperatures below ∼180 K, ice nucleation on JSC Mars-1 requires significant supersaturation, potentially impacting the Martian hydrological cycle.

Observation of ice nucleation in acoustically levitated water drops

The supercooling and nucleation of acoustically levitated water drops were investigated at two different sound pressure levels (SPL). These water drops were supercooled by 13to16K at the low SPL of 160.6dB, whereas their supercoolings varied from 5to11K at the high SPL of 164.4dB. The maximum supercooling obtained in the experiments is 32K. Statistical analyses based on the classical nucleation theory reveal that the occurrence of ice nucleation in water drops is mainly confined to the surface region under acoustic levitation conditions and the enlargement of drop surface area caused by the acoustic radiation pressure reduces water supercoolability remarkably. A comparison of the nucleation rates at the two SPLs indicates that the sound pressure can strengthen the surface-dominated nucleation of water drops. The acoustic stream around levitated water drops and the cavitation effect associated with ultrasonic field are the main factors that induce surface-dominated nucleation.

Homogeneous Ice Nucleation in Water and Aqueous Solutions

AbstractFor Abstract see ChemInform Abstract in Full Text.

Homogeneous Ice Nucleation in Water and Aqueous Solutions

Abstract This review provides an introduction to ice nucleation processes in supercooled water and aqueous solutions. Concepts for experimental techniques suitable to study homogeneous ice nucleation are addressed, in particular differential scanning calorimetry of inverse emulsions. Ice nucleation data from aqueous solutions have been analyzed using two approaches, and the interrelations between those are examined. It is argued that the ice nucleation process is driven entirely by thermodynamic quantities and how this can be understood in the context of three proposed theories for supercooled liquid water. Ice nucleation data for pure water droplets surrounded by a gas have been compiled and evaluated; within experimental uncertainty neither a volume dependent nucleation process nor a surface dependent nucleation process is convincingly supported by the analysis. Finally, open questions in the area of supercooled aqueous solutions and ice nucleation are discussed.

Nucleation of crystalline phases of water in homogeneous and inhomogeneous environments.

We employ two-body and three-body bond-orientational order-parameters, in conjunction with non-Boltzmann sampling to calculate the free energy barrier to nucleation of crystalline phases of water. We find that, as the coupling between the successive peaks of the direct correlation function increases, the free energy barrier to nucleation decreases. On this basis we explain the important parameters that govern the nucleation rate involving crystalline phases of water in different homogeneous and inhomogeneous environments, giving a "unified picture" of ice nucleation in water.

Ultrasonic-induced nucleation of ice in water containing air bubbles

Cavitation induced by ultrasonic vibrations can cause nucleation of ice in supercooled water. In this study, the time required for ultrasonic-induced nucleation of ice was measured for water containing two different size distributions of air bubbles. When the water was supersaturated with air bubbles, there was a time lag of about 0.5 s between the onset of ultrasonic irradiation and the onset of ice nucleation, and the probability of ice nucleation was unusually high within 0.5–1.1 s after the onset of ultrasonic irradiation. These results cannot be explained by conventional models alone, in which the collapse of a cavitation bubble triggers the nucleation of ice. Secondary effects appear to also influence ice nucleation.

Differential scanning calorimetric study on ice nucleation in water and in aqueous solutions of hydroxyethyl starch

An experimental investigation has been performed on ice nucleation rates over a range of degrees of undercooling, in water and in 15%, 25% and 35% w/w aqueous solutions of hydroxyethyl starch. An emulsion of droplets of the aqueous phase to be studied was cooled in a differential scanning calorimeter. The heat of crystallization was measured from which the nucleation rate was deduced after the droplet size (assumed uniform) had been determined. All the results obtained are in the main consistent with classical nucleation theory. The presence of hydroxyethyl starch is found to lead to pronounced increases in the exponential factor; this effect may be explained by changes in the interfacial free energies between ice and the aqueous phases. Discrepancies seen at both the high and the low temperature ends of the scans can be attributed to contributions to the exotherms by droplets of volumes larger and smaller, respectively, than the average.

Heterogeneous primary nucleation of ice in water and aqueous solutions

The effect of the volume of the liquid sample, the degree of turbulence in the liquid, and the rate of cooling upon the probability of nucleation has been studied for water and aqueous solutions. Nucleation rates were measured for droplets nearly instantaneously cooled to a predetermined temperature. Also threshold temperatures for nucleation were determined in stirred externally cooled vessels. The liquids studied (tap water, distilled water, and orange juice) did not contain particles causing nucleation at supercoolings less than 6°C. Nucleation at smaller supercoolings is attributed to the nucleative action of surface irregularities of the vessel walls. Provided no air bubbles are dispersed in the liquid, the rate of stirring (degree of turbulence) appeared to have no influence upon the nucleation. The experimental results are inconsistent with the stochastic hypothesis of Bigg 7), the singular hypothesis of Langham and Mason 8) and the pseudo-singular hypothesis of Vali and Stansbury 10). They could, including those reported in literature 7, 8, 10) be explained by the assumption of three distinct probabilities of nucleation: namely, the probability per unit time that a particular particle can cause nucleation at equilibrium conditions; the probability per unit time that equilibrium is established; and the probability that a particle with characteristic properties is present in the sample.

Work of ice nucleation in water

Work of ice nucleation in water