Experimental study of forces between quasi-two-dimensional emulsion droplets near jamming
Experimental study of forces between quasi-two-dimensional emulsion droplets near jamming
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DOI：
10.1039/c3sm27287g
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发表时间：
2013-01-01
期刊：
影响因子：
3.4
通讯作者：
Weeks, Eric R.
中科院分区：
文献类型：
--
作者：
Desmond, Kenneth W.;Young, Pearl J.;Weeks, Eric R.
实验研究了准二维乳剂的干扰。我们的实验是在两个平行板之间的水包油乳液滴。从液滴的轮廓，我们可以确定每个液滴之间的力在很大范围内的面积分数。我们研究了三个双分散样本，它们在面积分数phi(c)近似于0.86时发生堵塞。我们的数据表明，对于phi > phi(c)，接触数和压力具有幂律依赖于phi = phi(c)，这与数值模拟中发现的临界尺度一致。此外，我们看到颗粒间力定律和压力缩放指数之间的联系，支持先前的计算观察。我们还观察到线状力链（大液滴间力链）延伸超过10个粒子长度，并检查其线性的起源。我们发现，大的力段的相对方向是随机的，力链线性的趋势不是由于邻近的大力方向的相关性，而是因为方向偏向于线性，以平衡每个液滴上的力。
We experimentally study the jamming of quasi-two-dimensional emulsions. Our experiments consist of oil-in-water emulsion droplets confined between two parallel plates. From the droplet outlines, we can determine the forces between every droplet over a wide range of area fractions phi. We study three bidisperse samples that jam at area fractions phi(c) approximate to 0.86. Our data show that for phi > phi(c), the contact numbers and pressure have power-law dependence on phi = phi(c) in agreement with the critical scaling found in numerical simulations. Furthermore, we see a link between the interparticle force law and the exponent for the pressure scaling, supporting prior computational observations. We also observe linear-like force chains (chains of large inter-droplet forces) that extend over 10 particle lengths, and examine the origin of their linearity. We find that the relative orientation of large force segments are random and that the tendency for force chains to be linear is not due to correlations in the direction of neighboring large forces, but instead occurs because the directions are biased towards being linear to balance the forces on each droplet.