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arXiv 0910.3151cond-mat.soft
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润湿梯度诱导的乳状液分离:实验和格子Boltzmann计算机模拟相结合的研究

Wetting gradient induced separation of emulsions: A combined experimental and lattice Boltzmann computer simulation study

Fathollah Varnik, Pagra Truman, Bin Wu, Petra Uhlmann, Dierk Raabe, Manfred Stamm

摘要:

通过实验和理论研究相结合的乳液的引导运动。工作的重点是通过一个逐步的(突然)改变润湿性能的基板沿给定的空间方向产生的驱动力有关的基本问题。二元乳液的实验明确表明,相对于基板的两个不同部分的流体组分(在我们的实验中为水)之一的选择性润湿性是足够的,以驱动分离过程。这些研究都伴随着近似的分析参数,以及格子玻尔兹曼计算机模拟,专注于润湿梯度对内部液滴动力学的影响,以及其相对强度相比,体积力驱动的流体流动。这些理论研究表明,相对于平面通道,在开放基底的情况下,润湿梯度诱导力对接触角和液体体积的依赖性在性质上不同。特别是,对于我们的实验的参数范围内,狭缝的几何形状被发现产生相当高的分离力相比,开放基板。

英文摘要:

Guided motion of emulsions is studied via combined experimental and theoretical investigations. The focus of the work is on basic issues related to driving forces generated via a step-wise (abrupt) change in wetting properties of the substrate along a given spatial direction. Experiments on binary emulsions unambiguously show that selective wettability of the one of the fluid components (water in our experiments) with respect to the two different parts of the substrate is sufficient in order to drive the separation process. These studies are accompanied by approximate analytic arguments as well as lattice Boltzmann computer simulations, focusing on effects of a wetting gradient on internal droplet dynamics as well as its relative strength compared to volumetric forces driving the fluid flow. These theoretical investigations show qualitatively different dependence of wetting gradient induced forces on contact angle and liquid volume in the case of an open substrate as opposed to a planar channel. In particular, for the parameter range of our experiments, slit geometry is found to give rise to considerably higher separation forces as compared to open substrate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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