Molecular dynamics (MD) simulations were used to study the coexistence of solids and vapors of Lennard–Jones methane condensed within cylindrical carbon nanopores. The simulated unit cell includes both the inside and outside of the pores. This allowed us to observe the solid-vapor coexistence within the pores while simulating the pressure depression of the bulk vapor outside the pores. The condensates in the pores were cooled in stages, and the equilibrium vapor pressures were determined at each temperature. The obtained vapor–solid coexistence curves showed significantly lower shifts in pressure than those in the bulk phase. The results of the MD simulations were compared with the Clausius–Clapeyron equation starting from the triple point in the nanopores. The thermodynamic model successfully predicted the simulation results without introducing tunable parameters, demonstrating this concept’s validity. Thus, a whole Lennard-Jones phase diagram in cylindrical nanopores can now be predicted.

分子动力学 (MD) 模拟用于研究冷凝在圆柱形碳纳米孔内的 Lennard-Jones 甲烷的固体和蒸汽的共存。模拟的晶胞包括孔的内部和外部。这使我们能够在模拟孔隙外大量蒸汽的压力降低的同时观察孔隙内的固气共存。孔隙中的冷凝物分阶段冷却，并在每个温度下测定平衡蒸气压。获得的气-固共存曲线显示出明显低于体相的压力变化。从纳米孔中的三相点开始，将 MD 模拟的结果与克劳修斯-克拉珀龙方程进行比较。热力学模型在没有引入可调参数的情况下成功预测了模拟结果，证明了这一概念的有效性。因此，现在可以预测圆柱形纳米孔中的整个 Lennard-Jones 相图。