Bey Romain, Coasne Benoit, Picard Cyril
Univ. Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France.
J Chem Phys. 2020 Mar 7;152(9):094707. doi: 10.1063/1.5143201.
A novel mechanical approach is developed to explore by means of atom-scale simulation the concept of line tension at a solid-liquid-vapor contact line as well as its dependence on temperature, confinement, and solid/fluid interactions. More precisely, by estimating the stresses exerted along and normal to a straight contact line formed within a partially wet pore, the line tension can be estimated while avoiding the pitfalls inherent to the geometrical scaling methodology based on hemispherical drops. The line tension for Lennard-Jones fluids is found to follow a generic behavior with temperature and chemical potential effects that are all included in a simple contact angle parameterization. Former discrepancies between theoretical modeling and molecular simulation are resolved, and the line tension concept is shown to be robust down to molecular confinements. The same qualitative behavior is observed for water, but the line tension at the wetting transition diverges or converges toward a finite value depending on the range of solid/fluid interactions at play.
一种新颖的力学方法被开发出来，通过原子尺度模拟来探索固-液-气接触线处的线张力概念及其对温度、限制条件和固/液相互作用的依赖性。更确切地说，通过估计在部分湿润孔隙内形成的直线接触线沿线方向和垂直方向施加的应力，可以估计线张力，同时避免基于半球形液滴的几何缩放方法所固有的缺陷。发现 Lennard-Jones 流体的线张力遵循一种通用行为，其温度和化学势效应都包含在一个简单的接触角参数化中。理论建模与分子模拟之间以前的差异得到了解决，并且线张力概念在分子限制条件下也被证明是稳健的。对于水也观察到了相同的定性行为，但在润湿转变时的线张力根据所涉及的固/液相互作用范围会发散或收敛到一个有限值。
