Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.
Langmuir. 2013 Oct 15;29(41):12623-7. doi: 10.1021/la402653f. Epub 2013 Oct 4.
Using molecular dynamics (MD), we investigate the importance of liquid-vapor interface topography in designing low-friction nanoengineered superhydrophobic surfaces. Shear flow is simulated on patterned surfaces. The relationship between the effective slip length and bubble meniscus curvature is attained by generating entrapped bubbles with large protrusion angles on patterned surfaces with nanoholes. We show that protruding bubbles can induce significant friction, which hinders the slip characteristics produced on liquid-vapor interfaces. By comparing surfaces with nanoholes and nanopillars, we also demonstrate that the continuity of the liquid-vapor interface can greatly influence slip. Our MD results yield an asymptotic behavior of slip length with varying gas fractions, which are found to be consistent with observations from simulations and analytical models produced in continuum studies.
我们利用分子动力学（MD）研究了液-气界面形貌在设计低摩擦纳米工程超疏水表面中的重要性。在图案化表面上模拟剪切流。通过在具有纳米孔的图案化表面上生成具有大突出角的被困气泡，获得有效滑移长度与气泡弯月面曲率之间的关系。我们表明，突出的气泡会引起显著的摩擦，从而阻碍液-气界面产生的滑移特性。通过比较具有纳米孔和纳米柱的表面，我们还证明了液-气界面的连续性会极大地影响滑移。我们的 MD 结果得出了滑移长度随气体分数变化的渐近行为，这与连续体研究中模拟和分析模型的观察结果一致。
