论文标题
球形纳米光的界面热力学：通过氢键网络对表面张力的分子理解
Interfacial thermodynamics of spherical nanodroplets: Molecular understanding of surface tension via hydrogen bond network
论文作者
论文摘要
表面张力在相变中起无处不在的作用，包括大气液滴的凝结或蒸发。尤其是，了解1 nm量表的临界核的界面热力学对于成核激活能屏障的分子表征很重要。在这里，我们研究了具有分子动力学和密度功能理论的球形纳米圆形的表面张力，并发现表面张力显着降低了1 nm的半径低于1 nm的半径，其分析表达始终源自经典的Tolman方程。尤其是，纳米光的自由能分析表明，表面张力的变化主要源自界面分子的构型能量，随着液滴尺寸降低，越来越多的氢键网络证明了界面分子的构型能。我们的结果可以应用于与分子波动相关的与界面相关的现象，例如在亚NM等级上的生物分子吸附，其中宏观热力学数量不明确。
Surface tension plays a ubiquitous role in phase transitions including condensation or evaporation of atmospheric liquid droplets. Especially, understanding of interfacial thermodynamics of the critical nucleus of 1 nm scale is important for molecular characterization of the activation energy barrier of nucleation. Here, we investigate surface tension of spherical nanodroplets with both molecular dynamics and density functional theory, and find that surface tension decreases appreciably below 1 nm radius, whose analytic expression is consistently derived from the classic Tolman's equation. In particular, the free energy analysis of nanodroplets shows that the change of surface tension originates dominantly from the configurational energy of interfacial molecules, which is evidenced by the increasingly disrupted hydrogen bond network as the droplet size decreases. Our result can be applied to the interface-related phenomena associated with molecular fluctuations such as biomolecule adsorption at sub-nm scale where the macroscopic thermodynamic quantities are ill-defined.
