Ice nucleation mechanisms and the maintenance of supercooling in water under mechanical vibration

Abstract

The freezing of supercooled liquids is closely related to many fields. Vibration is one of the most common mechanical disturbances to induce nucleation. However, there has been no systematic study and understanding of ice nucleation mechanisms and how to maintain the stability of supercooled water under vibration. We studied ice nucleation from water in vials by using mechanical vibration as excitation. The results showed that it accelerates nucleation generally. Nevertheless, as the supercooling or the vibration intensity is low, or the flow is hindered, vibration has little effect on the supercooling stability. More meaningfully, if the flow is completely limited under isochoric conditions, vibration has no effect on the freezing temperature of supercooled water, and ice nucleation depends entirely on the container itself. It was demonstrated that stretching water and the formation of cavitation bubbles are the main factors affecting nucleation. The study further revealed three kinds of ice nucleation mechanisms: wall-contact, negative-pressure, and high-pressure nucleation. The findings are helpful for recognizing the effects of vibration on supercooling related to biological tissue preservation and transportation, energy storage, etc., and contribute to understanding the fundamental nucleation mechanism of the solid phase in supercooled liquids under mechanical disturbances.