Water above spinodal

Abstract

The liquid spinodal, which is the bedrock of water thermodynamics, has long been discussed alongside the elusive liquid-liquid critical point hidden behind the limit of homogeneous nucleation. This has inspired numerous scenarios that attempt to explain water anomalies. Despite recent breakthrough experiments eliminating several of thous scenarios, we lacked a tool to localize the spinodal and the liquid-liquid critical point. We constructed a unique equation of state combining the famous Speedy's equation and the liquid-liquid critical point to remove that deficit and to review these explanations. For the first time, the proposed equation of state independently depicts the spinodal in the presence of the liquid-liquid critical point and demonstrates that the explanation for water anomalies based on the reentrance of the spinodal is not valid; this feature (reentering the spinodal) was solely predicted based on the curved density surface caused by the existence of the second critical point. However, the critical point alone is not sufficient to explain the shape of the density surface of water. In the new equation, hydrogen bond cooperativity is important to force the critical point to exist outside of zero temperature. Together with mounting evidence for the existence of a compressibility maximum behind the homogeneous nucleation limit at positive pressure, the findings practically exclude all explanations for water anomalies except for the existence of the liquid-liquid critical point at positive pressure. Finally, an extensive study of heat capacity demonstrated profound disagreement between the two major experimental heat capacity datasets and identified the more accurate dataset.

References in corpus (5)

• Equation of state for supercooled water at pressures up to 400 MPa
• Compressibility anomalies in stretched water and their interplay with density anomalies
• Thermodynamics of Fluid Polyamorphism
• The stability-limit conjecture revisited
• High-Resolution Adiabatic Calorimetry of Supercooled Water

Cited by in corpus (10)

• Phase Transitions Affected by Natural and Forceful Molecular Interconversion
• Shear viscosity and Stokes-Einstein violation in supercooled light and heavy water
• Modeling Fluid Polyamorphism Through a Maximum-Valence Approach
• Interfacial Properties of Fluids Exhibiting Liquid Polyamorphism and Water-Like Anomalies
• Water at negative pressure: Nuclear quantum effects
• Generic Maximum-Valence Model for Fluid Polyamorphism
• Shear and bulk viscosities of water up to 1.6 GPa and anomaly in the structural relaxation time
• Hamiltonian limited valence model for liquid polyamorphism
• Minimal microscopic model for liquid polyamorphism and water-like anomalies
• Thermodynamic Modeling of Fluid Polyamorphism in Hydrogen at Extreme Conditions