Wetting on structured substrates
Wetting on structured substrates
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结构化基材上的润湿
DOI：
10.1088/0953-8984/17/9/017
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
M. Rauscher
中科院分区：
文献类型：
--
作者：
S. Dietrich;M. N. Popescu;M. Rauscher
化学图案化的表面在微流体应用的背景下具有重要意义，并且这种装置的小型化旨在产生纳米级的结构。而在微米尺度上，液体流动的纯宏观描述是有效的，在纳米尺度上，长程分子间相互作用，热波动，如毛细管波，最后是液体的分子结构变得重要。我们讨论了微米尺度和纳米尺度化学图案化基底上的流动之间最重要的概念差异，并制定了与通道宽度、通道间隔和通道弯曲半径相关的纳米流体的四个设计问题。作为一个具体的例子，纳米尺度的运输，我们提出了一个微观模型的动力学扩散的单分子膜上均匀的基板。该模型在一个均匀的基板上的动力学Monte Carlo模拟揭示了一个复杂的时空结构的提取单层，其中包括出现的接口和密度分布的缩放特性。这些功能进行了讨论和合理化内相应的连续极限来自微观动力学。相应的扩展行为的图案化基板上简要地解决。
Chemically patterned surfaces are of significant interest in the context of microfluidic applications, and miniaturization of such devices aims at generating structures on the nano-scale. Whereas on the micron scale purely macroscopic descriptions of liquid flow are valid, on the nanometre scale long-ranged inter-molecular interactions, thermal fluctuations such as capillary waves, and finally the molecular structure of the liquid become important. We discuss the most important conceptual differences between flow on chemically patterned substrates on the micron scale and on the nanometre scale, and formulate four design issues for nanofluidics related to channel width, channel separation, and channel bending radius. As a specific example of nano-scale transport we present a microscopic model for the dynamics of spreading of monolayers on homogeneous substrates. Kinetic Monte Carlo simulations of this model on a homogeneous substrate reveal a complex spatio-temporal structure of the extracted monolayer, which includes the emergence of interfaces and of scaling properties of density profiles. These features are discussed and rationalized within the corresponding continuum limit derived from the microscopic dynamics. The corresponding spreading behaviour on a patterned substrate is briefly addressed.