Acta Chimica Sinica ›› 2021, Vol. 79 ›› Issue (1): 108-118.

Article

### 单分子层受限冰-水共存界线毛细波与固-液相变动力学

1. a 华东师范大学 物理与电子科学学院 凝聚态物理研究所 上海 200241
• 投稿日期:2020-09-13 发布日期:2020-11-24
• 通讯作者: 杨洋
• 作者简介:
• 基金资助:
国家自然科学基金(11874147); 中央高校基本科研业务费专项资金和华东师范大学公共创新服务平台(001)

### Crystal-Melt Interface Kinetics and the Capillary Wave Dynamics of the Monolayer Confined Ice-Water Coexistence Lines

Zun Lianga, Xin Zhanga, Songtai Lva, Hongtao Lianga, Yang Yanga,*()

1. a School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
• Received:2020-09-13 Published:2020-11-24
• Contact: Yang Yang
• Supported by:
the National Natural Science Foundation of China(11874147); the Fundamental Research Funds for the Central Universities, and East China Normal University Multifunctional Platform for Innovation(001)

The ice-water interface's kinetics has long been paid much attention because of its central role in ice nucleation, growth and surface/interface melting. However, there exist few studies focused on the kinetics of the confined ice-water interface. In this paper, we employ the equilibrium molecular dynamics simulation and the phase equilibrium technique for the confined water and ice to study the 1D crystal-melt coexistence line of an equilibrium mono-layer ice-water coexistence system, described by two well-known water molecule models, i.e., constant dipole moment TIP4P/2005 model and polarizable SWM4-NDP water model. The mono-layer ice-water phase equilibria are confined in the hydrophobic slab pore of 0.65 nm, under 0.5 GPa lateral pressure. By tracking the 1D ice-water coexistence line's position, we calculate the power spectrum of the equilibrium line fluctuation and the time-dependent autocorrelation function of the line fluctuation Fourier amplitudes and then calculate a series of kinetic properties of the 1D crystal-melt coexistence line. We demonstrate that the processes involved in the relaxation of the crystal-melt coexistence line fluctuation with long wavelengths are coupled with a fast and a slow decay process characterized by two distinct time scales, while just the slow decay processes dominate the crystal-melt coexistence line fluctuation with short wavelengths. By comparing with bulk ice-water interface systems, we find that the high-frequency processes such as Rayleigh waves participate more in the relaxation of the 1D crystal-melt coexistence line fluctuation. We see that the wave vector dependence of the characteristic relaxation time (of the crystal-melt line fluctuation) is consistent with the crystal-melt interface's existing kinetic theory. Nevertheless, the characteristic relaxation time of the 1D crystal-melt coexistence line relaxation is around one order of magnitude lower than that of the 2D bulk ice-water interface system. We calculate the kinetic coefficients of the 1D crystal-melt coexistence line for the two water model systems, compare with the bulk interface systems, and find the kinetic coefficient of the confined ice-water (crystal-melt) coexistence line is much higher than that of the bulk ice-water interface system. The significant increase in the magnitude of the kinetic coefficient of the confined 1D ice-water coexistence line system may be understood by the substantial suppression of the rotational degree of freedom of the confined water molecules. The current achievement of the fundamental insight and simulation results could potentially facilitate the theoretical advancements in designing new devices of ultrafast phase-change (energy storage, sensor) devices based on confined water systems.