Solid–liquid phase transition of Lennard-Jones fluid in slit pores under tensile condition
Solid–liquid phase transition of Lennard-Jones fluid in slit pores under tensile condition
复制标题
拉伸条件下狭缝孔隙中 Lennard-Jones 流体的固液相变
DOI：
10.1063/1.481643
复制
发表时间：
2000
影响因子：
4.4
通讯作者：
K. Higashitani
中科院分区：
文献类型：
--
作者：
M. Miyahara;H. Kanda;M. Shibao;K. Higashitani
研究了平衡气相压力对纳米孔中简单流体冻结的影响。我们采用分子动力学（MD）技术在一个单位细胞与假想的气相，这具有容易确定的平衡蒸汽压的好处。结果表明，该方法与巨正则蒙特卡罗（GCMC）方法所得结果一致，并具有冻结与融化之间的滞后较小的特点。分子动力学模拟表明，液-固相变，在一个恒定的温度下，在饱和以下的平衡汽相压力的变化。因此，确定的固-液共存线表现出显着的依赖性的凝固点对小的变化，在体相蒸汽压，这意味着在纳米孔的冻结拉伸效应的重要性。基于连续介质和各向同性假设，建立了一个简单的模型，成功地描述了毛细管效应对凝固点移动的影响，即使在宽度为2 nm的细孔中也是如此。
The effect of equilibrium vapor-phase pressure onto freezing of a simple fluid in a nanopore is examined. We employ a molecular dynamics (MD) technique in a unit cell with imaginary gas phase, which has the benefit of easy determination of equilibrium vapor pressure. The method is shown to give consistent results with those by the grand canonical Monte Carlo (GCMC) method, and to have better feature of smaller degree of hysteresis between freezing and melting. The MD simulations showed liquid–solid phase transitions, at a constant temperature, with the variation in the equilibrium vapor-phase pressure below the saturated one. Thus-determined solid–liquid coexistence lines exhibited significant dependence of the freezing point against small changes in the bulk–phase vapor pressure, which implies the importance of tensile effect on freezing in nanopores. The capillary effect on the shift in freezing point was successfully described by a simple model based on continuum and isotropic assumption, even in a pore as small as 2 nm in width.