Stick-Slip Motion of Moving Contact Line on Chemically Patterned Surfaces
Stick-Slip Motion of Moving Contact Line on Chemically Patterned Surfaces
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DOI：
10.4208/cicp.2009.09.042
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发表时间：
2009
影响因子：
3.7
通讯作者：
Congmin Wu;Siu-Long Lei;T. Qian;Xiaoping Wang
中科院分区：
文献类型：
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作者：
Congmin Wu;Siu-Long Lei;T. Qian;Xiaoping Wang
基于我们针对固体表面不混溶两相流的连续流体动力学模型，预测了化学图案表面上移动接触线的粘滑运动 [Wang et al., J. Fluid Mech., 605 (2008), pp. 59-78]。在本文中，我们表明连续体预测可以通过分子动力学（MD）模拟来定量验证。我们的 MD 模拟是针对泊肃叶流几何中由两个平面实体壁限制的两种不混溶的 Lennard-Jones 流体进行的。特别是，一个固体表面被化学图案化为具有交替的条纹。为了进行比较，使用 MD 模拟中直接测量的材料参数对连续体模型进行数值求解。从振荡的流体-流体界面到移动接触线的间歇粘滑运动，我们在连续介质和MD结果之间取得了定量一致性。这一一致性归因于我们的连续介质模型中广义纳维边界条件对分子尺度的准确描述。还给出了流体-流体界面松弛动力学的数值结果，与基于 Onsager 最小能量耗散原理的理论分析一致。 PACS：68.08.-p、83.50.Rp、83.10.Mj、83.10.Ff
Based on our continuum hydrodynamic model for immiscible two-phase flows at solid surfaces, the stick-slip motion has been predicted for moving contact line at chemically patterned surfaces [Wang et al., J. Fluid Mech., 605 (2008), pp. 59-78]. In this paper we show that the continuum predictions can be quantitatively verified by molecular dynamics (MD) simulations. Our MD simulations are carried out for two immiscible Lennard-Jones fluids confined by two planar solid walls in Poiseuille flow geometry. In particular, one solid surface is chemically patterned with alternating stripes. For comparison, the continuum model is numerically solved using material parameters directly measured in MD simulations. From oscillatory fluid-fluid interface to intermittent stick-slip motion of moving contact line, we have quantitative agreement between the continuum and MD results. This agreement is attributed to the accurate description down to molecular scale by the generalized Navier boundary condition in our continuum model. Numerical results are also presented for the relaxational dynamics of fluid-fluid interface, in agreement with a theoretical analysis based on the Onsager principle of minimum energy dissipation. PACS: 68.08.-p, 83.50.Rp, 83.10.Mj, 83.10.Ff