Ingebrigtsen Trond S, Dyre Jeppe C
DNRF Centre "Glass and Time", IMFUFA, Department of Sciences, Roskilde University, Postbox 260, DK-4000 Roskilde, Denmark.
Soft Matter. 2014 Jun 28;10(24):4324-31. doi: 10.1039/c3sm52441h.
Bulk and nanoconfined liquids have very different physics; for instance, nanoconfined liquids show stratification and position-dependent relaxation processes. A number of similarities between bulk and nanoconfined liquids have nevertheless been reported in computer simulations during the last decade. Inspired by these observations, we present results from molecular dynamics computer simulations of four nanoconfined liquids (the single-component Lennard-Jones liquid, the Kob-Andersen binary Lennard-Jones mixture, an asymmetric dumbbell model, and the Dzugutov liquid) demonstrating also a microscopic similarity between bulk and nanoconfined liquids. The results show that the interaction range for the wall-liquid and liquid-liquid interactions of the nanoconfined liquid is identical to that of the bulk liquid if the liquid is "Roskilde simple" in bulk as well as nanoconfinement, i.e., exhibits strong correlations between virial and potential-energy equilibrium fluctuations in the NVT ensemble. Under this condition, interactions beyond the first coordination shell may be ignored, in particular for the wall-liquid interactions. This is shown not to be the case for non-Roskilde-simple liquids.
宏观液体和纳米受限液体具有非常不同的物理性质；例如，纳米受限液体表现出分层和位置依赖的弛豫过程。然而，在过去十年的计算机模拟中，已经报道了宏观液体和纳米受限液体之间的一些相似之处。受这些观察结果的启发，我们展示了四种纳米受限液体（单组分 Lennard-Jones 液体、Kob-Andersen 二元 Lennard-Jones 混合物、不对称哑铃模型和 Dzugutov 液体）的分子动力学计算机模拟结果，这些结果也证明了宏观液体和纳米受限液体之间的微观相似性。结果表明，如果纳米受限液体在宏观和纳米限域中都是“罗斯基勒简单”的，即表现出 NVT 系综中维里系数和势能平衡涨落之间的强相关性，那么纳米受限液体的壁 - 液相互作用和液 - 液相互作用的作用范围与宏观液体相同。在这种情况下，第一配位层之外的相互作用可以忽略不计，特别是对于壁 - 液相互作用。对于非罗斯基勒简单液体，情况并非如此。
