论文标题
封闭的流动性悬浮液的集体动力和流变学
Collective dynamics and rheology of confined phoretic suspensions
论文作者
论文摘要
与其生物学对应物类似,化学活性自摩托游泳者的悬浮液表现出由于粒子间相互作用而涉及自组织过程的非平凡动力学。我们使用动力学模型来稀释自动化学的JANUS颗粒,分析了受压驱动流对这些集体行为的影响以及趋化性聚集对活动液体有效粘度的影响。当增加强加的压力驱动流动的强度时,可以确定四个动态状态,每种状态与游泳者的流动和化学引起的重新定位以及约束的限制相关。有趣的是,我们观察到,在自动化学术聚集出现后,推动器(分别拉动)流体动力学签名的效果被降低(分别增加)剪切悬浮液的有效粘度。我们的结果提供了有关集体动力学在复杂环境中的作用的新见解,这与合成和生物系统有关。
Similarly to their biological counterparts, suspensions of chemically-active autophoretic swimmers exhibit nontrivial dynamics involving self-organization processes as a result of inter-particle interactions. Using a kinetic model for a dilute suspension of autochemotactic Janus particles, we analyse the effect of a confined pressure-driven flow on these collective behaviours and the impact of chemotactic aggregation on the effective viscosity of the active fluid. Four dynamic regimes are identified when increasing the strength of the imposed pressure-driven flow, each associated with a different collective behaviour resulting from the competition of flow- and chemically-induced reorientation of the swimmers together with the constraints of confinement. Interestingly, we observe that the effect of the pusher (resp. puller) hydrodynamic signature, which is known to reduce (resp. increase) the effective viscosity of a sheared suspension, is inverted upon the emergence of autochemotactic aggregation. Our results provide new insights on the role of collective dynamics in complex environments, which are relevant to synthetic as well as biological systems.