Ice nucleation behavior and pathways in water films under confinement conditions

SC Wang and LP Zhou and XZ Du, INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 242, 126871 (2025).

DOI: 10.1016/j.ijheatmasstransfer.2025.126871

The ice nucleation behavior of water under confined conditions is different from that of bulk water, and it is challenging to observe this behavior experimentally at the nanoscale. In this paper, molecular dynamics simulations are used to study the ice nucleation behavior and pathways of freestanding, sessile, and nanoconfined water films with thicknesses ranging from 40 & Aring; to 250 & Aring;. The results show that the size effect contributes to the reduction of the ice nucleation barrier and the kinetic prefactor, which are in competition with each other. The latter eventually dominates and influences the ice nucleation rates. The details of critical nucleus formation and growth are also presented at the molecular level. When solid-liquid interfaces are present, both homogeneous and heterogeneous ice nucleation are observed, but there is no significant effect on the magnitude of the ice nucleation rate. In the meantime, stacking disordered ice and secondary nucleation are observed, and stacking faults tend to occur during ice growth. It is found that when the size is small, the interfacial effects are more pronounced, leading to a higher probability of heterogeneous nucleation and formation of defect-free ice crystals in thinner nanoconfined water films. This study demonstrates the influence of size effects and interfacial effects on the ice nucleation behavior of water films, which facilitates the understanding of low-temperature phase changes related to different fields such as atmospheric science, nanoscience, and biology.

Return to Publications page