The behavior of active diffusiophoretic suspensions: An accelerated Laplacian dynamics study.
The behavior of active diffusiophoretic suspensions: An accelerated Laplacian dynamics study.
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主动扩散电泳悬浮液的行为：加速拉普拉斯动力学研究。
DOI：
10.1063/1.4963722
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
J. Brady
中科院分区：
文献类型：
--
作者：
Wen Yan;J. Brady
扩散电泳是胶体颗粒响应于化学溶质的浓度梯度而移动的过程。化学活性颗粒通过表面化学反应产生溶质浓度梯度，这可以导致它们自身的运动-Janus颗粒的自扩散电泳-以及其他附近颗粒的运动-正常的向下梯度扩散电泳。由活性粒子产生的浓度扰动的长程性质导致粒子之间的强烈相互作用，并可能导致形成团簇，甚至在活性物质系统中常见的共存的稠密和稀疏区域。在这项工作中，我们提出了一个通用的方法来确定多粒子溶质浓度场允许成千上万的反应性粒子的运动的动态模拟。与模拟方法，我们首先澄清和证明的概念，“化学筛选”，即长程相互作用成为指数筛选，这是必不可少的，否则扩散电泳悬浮液将是无条件不稳定的。模拟结果表明，均匀反应的粒子，不自我推进，形成松散的集群，但没有共存观察。模拟还揭示了存在一个稳定性阈值-当“化学燃料”浓度足够低时，热布朗运动能够克服扩散电泳吸引力。自推进的Janus粒子表现出共存性，但有趣的是，成团的稳定性阈值不受自运动的影响。
Diffusiophoresis is the process by which a colloidal particle moves in response to the concentration gradient of a chemical solute. Chemically active particles generate solute concentration gradients via surface chemical reactions which can result in their own motion - the self-diffusiophoresis of Janus particles - and in the motion of other nearby particles - normal down-gradient diffusiophoresis. The long-range nature of the concentration disturbance created by a reactive particle results in strong interactions among particles and can lead to the formation of clusters and even coexisting dense and dilute regions often seen in active matter systems. In this work, we present a general method to determine the many-particle solute concentration field allowing the dynamic simulation of the motion of thousands of reactive particles. With the simulation method, we first clarify and demonstrate the notion of "chemical screening," whereby the long-ranged interactions become exponentially screened, which is essential for otherwise diffusiophoretic suspensions would be unconditionally unstable. Simulations show that uniformly reactive particles, which do not self-propel, form loosely packed clusters but no coexistence is observed. The simulations also reveal that there is a stability threshold - when the "chemical fuel" concentration is low enough, thermal Brownian motion is able to overcome diffusiophoretic attraction. Janus particles that self-propel show coexistence, but, interestingly, the stability threshold for clustering is not affected by the self-motion.
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影响因子：
2.4
作者：
Ebbens, Stephen;Jones, Richard A. L.;Howse, Jonathan R.
通讯作者：
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影响因子：
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作者：
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影响因子：
2.4
作者：
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影响因子：
8.6
作者：
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通讯作者：
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