In this work we examine the nucleation from NaCl aqueous solutions within nano-confined environments, employing enhanced sampling molecular dynamics simulations integrated with machine learning-derived reaction coordinates. Through our simulations, we successfully induce phase transitions between solid, liquid, and a hydrated phase, typically observed at lower temperatures in bulk environments. Interestingly, while generally speaking nano-confinement serves to stabilize the solid phase and elevate melting points, there are subtle variations in the thermodynamics of competing phases with the precise extent of confinement. Our simulations explain these findings by underscoring the significant role of water, alongside ion aggregation and subtle, anisotropic dielectric behavior, in driving nucleation within nano-confined environments. This report thus provides a framework for sampling, analyzing and understanding nucleation processes under nano-confinement.

中文翻译：

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纳米受限环境中 NaCl 成核的原子尺度洞察


在这项工作中，我们采用增强采样分子动力学模拟与机器学习衍生的反应坐标相结合，研究了纳米限制环境中 NaCl 水溶液的成核作用。通过模拟，我们成功诱导了固体、液体和水合相之间的相变，通常在本体环境中的较低温度下观察到。有趣的是，虽然一般来说纳米限制可以稳定固相并提高熔点，但竞争相的热力学与限制的精确程度存在细微的变化。我们的模拟通过强调水以及离子聚集和微妙的各向异性介电行为在驱动纳米限制环境中的成核过程中的重要作用来解释这些发现。因此，本报告为采样、分析和理解纳米约束下的成核过程提供了一个框架。