Tuning Drop Motion by Chemical Chessboard-Patterned Surfaces: A Many-Body Dissipative Particle Dynamics Study.
Tuning Drop Motion by Chemical Chessboard-Patterned Surfaces: A Many-Body Dissipative Particle Dynamics Study.
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DOI：
10.1021/acs.langmuir.7b04162
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发表时间：
2018-02
期刊：
影响因子：
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通讯作者：
Chensen Lin;Shuo Chen;L. Xiao;Yang Liu
中科院分区：
文献类型：
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作者：
Chensen Lin;Shuo Chen;L. Xiao;Yang Liu
控制液滴在固体表面的运动具有广泛的技术影响。在这项研究中，采用多体耗散粒子动力学（MDPD）来研究液滴在由正方形或三角形小块组成的化学棋盘图案表面上的行为。基于真实流体的表面张力、粘度和密度建立了模型的比例关系，并将一种改进的接触角测量技术引入到MDPD系统中。对于在具有不同小块尺寸的水平面上的液滴，研究了其平衡形态。发现临界邦德数（即解开液滴所需的临界无量纲力）受到小块尺寸和形状的强烈影响。一旦液滴开始移动，小块图案和尺寸对速度波动有强烈影响，而对平均速度影响较弱。有趣的是，仅通过调整小块角度，除了常见的直线前进路径外，还观察到另外两种路径模式（之字形和倾斜形），这表明液滴的前进路径可能根据小块角度而变化。据作者所知，这种现象在文献中尚未有报道。这项研究为探索通过无能量化学异质表面对液滴运动进行被动控制的可能性提供了一种有价值的工具，因此有助于工程师设计一种无需外部能量就能操控液滴运动的表面。
Controlling the motion of liquid drops on the solid surface has broad technological implications. In this study, the many-body dissipative particle dynamics (MDPD) was employed to study the drop behaviors on chemical chessboard-patterned surfaces formed by square or triangular tiles. The scaling relationship of the model was established based on the surface tension, viscosity, and density of a real fluid, and an improved contact angle measurement technique was introduced to the MDPD system. For drops on a horizontal plane with different tile sizes, the equilibrium morphology was examined. The critical Bond number, that is, the critical dimensionless force which is required to unpin the drop, was found strongly affected by the size and the shape of the tiles. Once the droplet begins to move, the tile pattern and the size strongly affect the velocity fluctuation while weakly affect the average velocity. Interestingly, besides the common straight forward path, two more route patterns (zigzag and oblique) were observed by only tuning the tile angle, indicating that the advancing routes of the drop may vary according to the tile angle. To the author's knowledge, this phenomenon has not been reported in the literature. This study provides a valuable tool to explore the possibility of passive control of the drop's motion by energy-free chemical heterogeneous surfaces and thus is helpful for engineers to design a surface that could manipulate the drop motion without external energy.