Interfacial Free Energy as the Key to the Pressure-Induced Deceleration of Ice Nucleation

TL;DR

This study reveals that increasing interfacial free energy at high pressures significantly slows ice nucleation, providing insights into cryopreservation, water amorphization, and climate modeling.

Contribution

It demonstrates that interfacial free energy increase with pressure is the key factor in decelerating ice nucleation, supported by computer simulations.

Findings

Interfacial free energy increases with pressure.

Slowing of nucleation rate is primarily due to interfacial free energy.

Molecular mechanism of ice nucleation clarified across pressures.

Abstract

The avoidance of water freezing is the holy grail in the cryopreservation of biological samples, food, and organs. Fast cooling rates are used to beat ice nucleation and avoid cell damage. This strategy can be enhanced by applying high pressures to decrease the nucleation rate, but the physics behind this procedure has not been fully understood yet. We perform computer experiments to investigate ice nucleation at high pressures consisting in embedding ice seeds in supercooled water. We find that the slowing down of the nucleation rate is mainly due to an increase of the ice I-water interfacial free energy with pressure. Our work also clarifies the molecular mechanism of ice nucleation for a wide pressure range. This study is not only relevant to cryopreservation, but also to water amorphization and climate change modeling.