Isochoric conditions enhance stability of metastable supercooled water

Abstract

Supercooling has recently emerged as a highly promising, multi-scale technique for low-temperature preservation of organs and tissues, preventing damaging ice formation while requiring relatively low doses of added cryoprotectants. However, current supercooling techniques are not thermodynamically stable; mild agitations can cause rapid and destructive ice formation throughout the system, rendering them unsuitable for transportation and sharply limiting applicability outside the controlled laboratory environment. In this experimental study, we report a simple thermodynamic alteration to standard supercooling protocols, the use of constant-volume (isochoric) conditions, which substantially increases the stability of the system in the face of various macroscopic perturbations, including drop-impact, vibration, ultrasonication, and thermal fluctuation. We identify this effect as driven by a possible combination of thermodynamic and kinetic factors, including reduction of microscopic density fluctuations, elimination of the air-water interface, and significant resistance to cavitation.