TL;DR: In this article, the authors present a comprehensive series of molecular dynamics simulations which suggest that the supercooling anomalies are caused by a newly identified critical point above which the two metastable amorphous phases of ice (previously shown to be separated by a line of first-order transitions) become indistinguishable.
Abstract: THE metastable extension of the phase diagram of liquid water exhibits rich features that manifest themselves in the equilibrium properties of water. For example, the density maximum at 4 °C and the minimum in the isothermal compressibility at 46 °C are thought to reflect the presence of singularities in the behaviour of thermodynamic quantities occurring in the supercooled region1 2. The 'stability–limit conjecture'3–5 suggests that these thermodynamic anomalies arise from a single limit of mechanical stability (spinodal line), originating at the liquid–gas critical point, which determines the limit of both superheating at high temperatures and supercooling at low temperatures. Here we present a comprehensive series of molecular dynamics simulations which suggest that, instead, the supercooling anomalies are caused by a newly identified critical point, above which the two metastable amorphous phases of ice (previously shown to be separated by a line of first-order transitions6,7) become indistinguishable. The two amorphous ice phases are thus incorporated into our understanding of the liquid state, providing a more complete picture of the metastable and stable behaviour of water.
TL;DR: This article showed that water can exist in two distinct "glassy" forms, low and high density amorphous ice, which may provide the key to understanding some of the puzzling characteristics of cold and supercooled water.
Abstract: That water can exist in two distinct ‘glassy’ forms — low- and high-density amorphous ice — may provide the key to understanding some of the puzzling characteristics of cold and supercooled water, of which the glassy solids are more-viscous counterparts. Recent experimental and theoretical studies of both liquid and glassy water are now starting to offer the prospect of a coherent picture of the unusual properties of this ubiquitous substance.
TL;DR: Amorphous solids are made mainly by cooling the liquid below the glass transition without crystallizing it, a method used since before recorded history1, and by depositing the vapour onto a cold plate2, as well as by several other methods as discussed by the authors.
Abstract: Amorphous solids are made mainly by cooling the liquid below the glass transition without crystallizing it, a method used since before recorded history1, and by depositing the vapour onto a cold plate2, as well as by several other methods3,4. We report here a new way—by ‘melting’ a solid by pressure below the glass transition of the liquid—and apply it to making a new kind of amorphous ice. Thus, ice I has been transformed to an amorphous phase, as determined by X-ray diffraction, by pressurizing it at 77 K to its extrapolated melting point of 10 kbar. At the melting point, the fluid is well below its glass transition. On heating at a rate of ∼2.6 K min−1 at zero pressure it transforms at ∼117 K to a second amorphous phase with a heat evolution of 42±∼8 J g−1 and at ∼152 K further transforms to ice I with a heat evolution of 92±∼15 J g−1. In one sample, ice Ic was formed and in another, existing crystals of ice Ih grew from the amorphous phase. Heating below the 117 K transition causes irreversible changes in the diffraction pattern, and a continuous range of amorphous phases can be made. Similar transformations will probably occur in all solids whose melting point decreases with increasing pressure if they can be cooled sufficiently for a transformation to a crystalline solid to be too slow.
TL;DR: In this article, it was shown that low-density amorphous ice (density 0.94 g cm−3) compressed at 77 K transforms to high-density Amorphous Ice (1.19 g cm −3 at zero pressure) at a sharp transition at 6±0.5 kbar.
Abstract: We recently reported1 a transition from ice Ih to a high-density amorphous phase at 10 kbar, 77 K. Here we report that low-density amorphous ice (density 0.94 g cm−3) compressed at 77 K transforms to high-density amorphous ice (1.19 g cm−3 at zero pressure) at a sharp transition at 6±0.5 kbar. The transition is at least as sharp as the previously reported1 transition and strongly resembles a first-order transition in its sharpness and large volume change. It appears to be the first example of an apparently first-order transition between amorphous solids and has implications not only for our understanding of the behaviour of condensed matter, but also for theories of planetary interiors.
TL;DR: In this article, the authors presented a study of the effects of different types of meteorological conditions on gas hydrates in the presence of a large number of people in the United States.
Abstract: Invited Papers: MOLECULAR SIMULATIONS OF GAS HYDRATE NUCLEATION EXTRATERRESTRIAL ICE WITH EMPHASIS ON AGGREGATION/ INTERACTION WITH ORGANIC MATTER: COLLISIONAL AND ACCRETIONAL PROPERTIES OF MODEL PARTICLES INTERACTIONS BETWEEN SNOW METAMORPHISM AND CLIMATE: PHYSICAL AND CHEMICAL ASPECTS ICE ADHESION AND ICE FRICTION MODIFICATION USING PULSED THERMAL POWER IMPROVING OUR UNDERSTANDING OF GAS HYDRATE FORMATION PROCESSES: THE IMPORTANCE OF MULTI-TECHNIQUE APPROACHES FAST THERMAL DESORPTION SPECTROSCOPY AND MICROCALORIMETRY: NEW TOOLS TO UNCOVER MYSTERIES OF ICE SELECTION FOR 'ICE RESISTANCE', ANTIFREEZE PROTEINS AND ICE OR HYDRATE INHIBITION Contributed Papers: RAMAN SCATTERING STUDY OF PROTON ORDERED ICE-XI SINGLE CRYSTAL ON THE PERFORMANCE OF SIMPLE PLANAR MODELS OF WATER IN THE VAPOR AND THE ICE PHASES PHASES OF SUPERCOOLED LIQUID WATER USING GAUSSIAN CURVATURE FOR THE 3D SEGMENTATION OF SNOW GRAINS FROM MICROTOMOGRAPHIC DATA ETHANOL HYDRATES FORMED BY GAS CONDENSATION: INVESTIGATIONS BY RAMAN SCATTERING AND X-RAY DIFFRACTION DISLOCATION PATTERNING AND DEFORMATION PROCESSES IN ICE SINGLE CRYSTALS DEFORMED BY TORSION FORMATION OF CARBON DIOXIDE GAS HYDRATES IN FREEZING SEDIMENTS AND DECOMPOSITION KINETICS OF THE HYDRATES FORMED FIRST-PRINCIPLES STUDY OF BJERRUM DEFECTS IN ICE Ih: AN ANALYSIS OF FORMATION AND MIGRATION PROPERTIES FIRST-PRINCIPLES STUDY OF MOLECULAR POINT DEFECTS IN ICE Ih: INTERSTITIAL VS VACANCY FROM ICE TO CO2 HYDRATES AND BACK - STUDY OF NUCLEATION AND INITIAL GROWTH USING SCANNING ELECTRON MICROSCOPY THE TEMPERATURE GRADIENT METAMORPHISM OF SNOW: MODEL AND FIRST VALIDATIONS USING X-RAY MICROTOMOGRAPHIC IMAGES SUM FREQUENCY GENERATION ON SINGLE-CRYSTALLINE ICE Ih MODELLING ICE Ic OF DIFFERENT ORIGIN AND STACKING-FAULTED HEXAGONAL ICE USING NEUTRON POWDER DIFFRACTION DATA FUNDAMENTAL STUDIES FOR A NEW H2 SEPARATION METHOD USING GAS HYDRATES SEGREGATION OF SALT IONS AT AMORPHOUS SOLID AND LIQUID SURFACES THEORETICAL STUDY ON GASES IN HEXAGONAL ICE INVESTIGATED BY THE MOLECULAR ORBITAL METHOD DEVELOPMENT OF IN SITU LOW TEMPERATURE INFRARED SPECTROSCOPY FOR A STUDY OF METHANE HYDRATE A MECHANISM FOR PHOTOCHEMICAL REACTIONS IN THE QUASI-LIQUID LAYER OF SNOW CRYSTALS IN POLAR REGIONS TOPOLOGICAL TRANSITIONS BETWEEN ICE PHASES THE IMPORTANCE OF O-O BONDING INTERACTIONS IN VARIOUS PHASES OF ICE THE CHEMICAL CHARACTER OF VERY HIGH PRESSURE ICE PHASES REAL-SPACE STUDY OF MECHANICAL INSTABILITY OF ICE XI ON A 'BOND-BY-BOND' BASIS WATER-VAPOR TRANSPORT IN SNOW WITH HIGH TEMPERATURE GRADIENT EXPERIMENTAL GEOSCIENCE IN A FREEZER: ICE AND ICY COMPOUNDS AS USEFUL EDUCATIONAL ANALOGUES FOR TEACHING EARTH AND PLANETARY MATERIALS SCIENCE AND THE PHYSICAL SCIENCES CLASSIFICATION OF LOW-ENERGY CONFIGURATIONS OF POLYHEDRAL WATER CLUSTERS FROM CUBE UP TO BACKMINSTERFULLERENE ENERGY OPTIMIZATION OF GAS HYDRATE FRAMEWORKS ON THE BASIS OF DISCRETE MODELS OF INTER-MOLECULAR INTERACTIONS MICROSTRUCTURE OF GAS HYDRATES IN POROUS MEDIA TACKLING THE PROBLEM OF HYDROGEN BOND ORDER AND DISORDER IN ICE THEORETICAL STUDY OF A HYDROXIDE ION WITHIN THE ICE-Ih LATTICE ATOMIC FORCE MICROSCOPY OF REARRANGING ICE SURFACES IONISATION OF HCl ON ICE AT VERY LOW TEMPERATURE EFFECTS OF LARGE GUEST SPECIES ON THERMODYNAMIC PROPERTIES OF STRUCTURE-H HYDRATES PREDICTION OF THE CELLULAR MICROSTRUCTURE OF SEA ICE BY MORPHOLOGICAL STABILITY THEORY THE PLANAR-CELLULAR TRANSITION DURING FREEZING OF NATURAL WATERS CRYSTAL GROWTH OF ICE-I/HYDRATE EUTECTIC BINARY SOLUTIONS X-RAY TOMOGRAPHIC CHARACTERIZATION OF IMPURITIES IN POLYCRYSTALLINE ICE EFFECTS OF ADDITIVES AND COOLING RATES ON CRYOPRESERVATION PROCESS OF RAT CORTICAL CELLS LABORATORY STUDIES OF THE FORMATION OF CUBIC ICE IN AQUEOUS DROPLETS HYDRATE PHASE TRANSFORMATIONS IMPOSED BY GAS EXCHANGE MECHANISM OF CAGE FORMATION DURING GROWTH OF CH4 AND Xe CLATHRATE HYDRATES: A MOLECULAR DYNAMICS STUDY GROWTH KINETICS ON INTERFACE BETWEEN { } PLANE OF ICE AND WATER INVESTIGATED BY A MOLECULAR DYNAMICS SIMULATION CHOOSING AN APPROPRIATE WATER MODEL FOR USE IN BIOMOLECULAR SIMULATIONS MICRO-RAMAN STUDY OF AIR CLATHRATE HYDRATES IN POLAR ICE FROM DOME FUJI, ANTARCTICA HIGH PRESSURE NMR OF HYDROGEN-FILLED ICES BY DIAMOND ANVIL CELL ON THE USE OF THE KIHARA POTENTIAL FOR HYDRATE EQUILIBRIUM CALCULATIONS A NEW STRUCTURE OF AMORPHOUS ICE PROMOTED BY RADIATIONS THE RADICAL CHEMISTRY IN IRRADIATED ICE SPEEDSKATE ICE FRICTION: REVIEW AND NUMERICAL MODEL - FAST 10 FIRST PRINCIPLES COMPUTATIONAL STUDY OF HYDROGEN BONDS IN ICE Ih FREEZING OF WATER ON ?-Al2O3 SURFACES NEW HYDROGEN ORDERED PHASES OF ICE MICROSCOPIC OBSERVATION AND IN-SITU RAMAN STUDIES ON SOME SINGLE-CRYSTALLINE GAS HYDRATES UNDER HIGH PRESSURE CLATHRATE HYDRATE FORMATION AND GROWTH: EXPERIMENTAL OBSERVATIONS VERSUS PREDICTED BEHAVIOUR EFFECT OF SNOW ACCRETION TO THE GPS ANTENNA ON POSITIONING PERFORMANCE GAS HYDRATES IN THE SYSTEM H2-CH4 - H2O AT PRESSURES OF 45 TO 220 ??? AND CONCENTRATIONS OF 0 TO 70 MOL % ?2 CHEMISTRY INDUCED BY IMPLANTATION OF REACTIVE IONS IN WATER ICE STRUCTURE H HYDRATE KINETICS STUDIED BY NMR SPECTROSCOPY DIELECTRIC RELAXATION OF ICE SAMPLES GROWN FROM VAPOR-PHASE OR LIQUID-PHASE WATER ESR OBSERVATION OF SELF-PRESERVATION EFFECT OF METHANE HYDRATE INVESTIGATION OF THE STRUCTURAL DISORDER IN ICE Ih USING NEUTRON DIFFRACTION AND REVERSE MONTE CARLO MODELLING FIRST-PRINCIPLES CALCULATION OF STRUCTURE AND DYNAMICAL PROPERTIES OF ORIENTATIONAL DEFECTS IN ICE EFFECTS OF ADDITIVES ON FORMATION RATES OF CO2 HYDRATE FILMS RIPPLE FORMATION MECHANISM ON ICICLES UNDER A THIN SHEAR FLOW MOLECULAR SIMULATIONS OF WATER FREEZING: BRINE REJECTION AND HOMOGENEOUS NUCLEATION IMPLICATIONS FOR AND FINDINGS FROM DEEP ICE CORE DRILLINGS - AN EXAMPLE: THE ULTIMATE TENSILE STRENGTH OF ICE AT HIGH STRAIN RATES ISOTHERMAL AMORPHOUS-AMORPHOUS-AMORPHOUS TRANSITIONS IN WATER MECHANICAL STRENGTH AND FLOW PROPERTIES OF ICE-SILICATE MIXTURE DEPENDING ON THE SILICATE CONTENTS AND THE SILICATE PARTICLE SIZES ADSORPTION OF ANTIFREEZE PROTEIN AND A COMMERCIAL LOW DOSAGE HYDRATE INHIBITIOR ON HYDROPHILIC AND HYDROPHOBIC SURFACES DIFFUSION, INCORPORATION, AND SEGREGATION OF ANTIFREEZE GLYCOPROTEINS AT THE ICE/SOLUTION INTERFACE Subject Index