Glass-to-cryogenic-liquid transitions in aqueous solutions suggested by crack healing

For decades, physicists, physical chemists, and biologists have been tremendously intrigued by the unusual thermodynamic and kinetic properties of supercooled water. Theories have been proposed to account for the properties but these theories remain contentious for lack of experimental evidence. We investigated phase behavior of water at cryogenic temperatures and showed clear experimental evidence that the two cryogenic glassy states of water (high-density amorphous and low-density amorphous) undergo glass-to-cryogenic-liquid transitions and they are thermodynamically separated by a first-order phase transition. The results provide insight into the physical origin of the anomalous properties of supercooled water.