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arXiv 1408.4087cond-mat.soft
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作为二维流体的肥皂膜:扩散和流场

Soap films as two-dimensional fluids: Diffusion and flow fields

Skanda Vivek, Eric R. Weeks

摘要:

我们观察示踪剂颗粒在肥皂膜中的扩散,以测量膜的二维(2D)粘性特性。我们用不同的水甘油混合物制作不同厚度的肥皂膜。对于薄膜,单颗粒扩散率与薄膜的参数(如厚度$h$)密切相关,但对于较厚的薄膜,这种关系破裂。值得注意的是,对于较厚的膜,扩散率比预期的更快,其中使用示踪剂颗粒直径$d$在$h/d = 5.2 \pm 0.9$处转变。这表明从纯2D扩散到更三维的扩散的过渡。此外,我们测量更大的长度尺度流场相关粒子运动,并找到很好的协议,预期从理论的2D流体为我们所有的电影,薄和厚。我们测量的有效二维粘度的肥皂膜使用单粒子扩散率测量薄膜,并使用两个粒子的相关测量在所有的电影。

英文摘要:

We observe tracer particles diffusing in soap films to measure the two-dimensional (2D) viscous properties of the films. We make soap films with a variety of water-glycerol mixtures and of differing thicknesses. The single-particle diffusivity relates closely to parameters of the film (such as thickness $h$) for thin films, but the relation breaks down for thicker films. Notably, the diffusivity is faster than expected for thicker films, with the transition at $h/d = 5.2 \pm 0.9$ using the tracer particle diameter $d$. This indicates a transition from purely 2D diffusion to diffusion that is more three-dimensional. Additionally, we measure larger length scale flow fields from correlated particle motions and find good agreement with what is expected from theory of 2D fluids for all our films, thin and thick. We measure the effective 2D viscosity of a soap film using single-particle diffusivity measurements in thin films, and using the two-particle correlation measurements in all films.

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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