Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon 69622 Villeurbanne, France.
LPS, UMR CNRS 8550, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France.
Phys Rev E. 2016 Mar;93(3):033123. doi: 10.1103/PhysRevE.93.033123. Epub 2016 Mar 24.
This work revisits capillary filling dynamics in the regime of nanometric to subnanometric channels. Using molecular dynamics simulations of water in carbon nanotubes, we show that for tube radii below one nanometer, both the filling velocity and the Jurin rise vary nonmonotonically with the tube radius. Strikingly, with fixed chemical surface properties, this leads to confinement-induced reversal of the tube wettability from hydrophilic to hydrophobic for specific values of the radius. By comparing with a model liquid metal, we show that these effects are not specific to water. Using complementary data from slit channels, we then show that they can be described using the disjoining pressure associated with the liquid structuring in confinement. This breakdown of the standard continuum framework is of main importance in the context of capillary effects in nanoporous media, with potential interests ranging from membrane selectivity to mechanical energy storage.
这项工作重新研究了纳米到亚纳米通道中毛细血管填充动力学。通过对碳纳米管中水分子的分子动力学模拟，我们表明，对于半径小于一纳米的管，填充速度和 Jurin 上升都与管半径呈非单调变化。引人注目的是，对于特定半径值，具有固定化学表面特性的情况下，这会导致管润湿性从亲水到疏水的约束诱导反转。通过与模型液态金属进行比较，我们表明这些效应并非仅限于水。然后，我们使用来自狭缝通道的补充数据表明，可以使用与受限液体结构相关的离隙压力来描述这些效应。在纳米多孔介质中毛细效应的背景下，这种对标准连续体框架的破坏非常重要，潜在的利益范围从膜选择性到机械能储存。
