论文标题
在超冷水中快速增加纳米流体滑移：动力学的关键作用
Fast Increase of Nanofluidic Slip in Supercooled Water: the Key Role of Dynamics
论文作者
论文摘要
纳米流体学是一个新兴领域，可提供创新的解决方案，以进行能量收集和淡化。这些应用的效率在很大程度上取决于液体固定滑动，这是由于粘度和界面摩擦之间的有利比率所产生的。使用分子动力学模拟，我们表明当水在其熔点以下冷却时，壁滑升高。对于石墨烯上的水，将滑移长度乘以5倍，在最低的模拟温度下达到230美元的$ 230 $ nm，$ t \ sim 225 $ k;纳米孔中的实验可以达到较低的温度，并且可能揭示出更大的变化。在实验中以及在抗冰面上流动的液滴中，还可以检测到在实验到达的超冷的水滑中预测的快速增加。我们通过粘度和散装密度弛豫动力学之间的脱钩来解释超冷方案中的异常滑移行为，我们将增强的壁型依赖性在种族间密度弛豫动力学方面合理化。通过提供对超冷政权界面和散装水中流体动力传输的分子机制的基本见解，这项研究与抗染色表面的设计有关，这也为探索超冷的纳米流体系统中的新行为铺平了道路。
Nanofluidics is an emerging field offering innovative solutions for energy harvesting and desalination. The efficiency of these applications depends strongly on liquid-solid slip, arising from a favorable ratio between viscosity and interfacial friction. Using molecular dynamics simulations, we show that wall slip increases strongly when water is cooled below its melting point. For water on graphene, the slip length is multiplied by up to a factor of five and reaches $230$nm at the lowest simulated temperature, $T \sim 225$K; experiments in nanopores can reach much lower temperatures and could reveal even more drastic changes. The predicted fast increase in water slip can also be detected at supercoolings reached experimentally in bulk water, as well as in droplets flowing on anti-icing surfaces. We explain the anomalous slip behavior in the supercooled regime by a decoupling between viscosity and bulk density relaxation dynamics, and we rationalize the wall-type dependency of the enhancement in terms of interfacial density relaxation dynamics. By providing fundamental insights on the molecular mechanisms of hydrodynamic transport in both interfacial and bulk water in the supercooled regime, this study is relevant to the design of anti-icing surfaces and it also paves the way to explore new behaviors in supercooled nanofluidic systems.
