Technical University Dresden, Zellescher Weg 19, 01069, Dresden, Germany.
Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569, Stuttgart, Germany.
Eur Phys J E Soft Matter. 2021 Mar 8;44(2):15. doi: 10.1140/epje/s10189-020-00006-5.
For monolayers of chemically active particles at a fluid interface, collective dynamics is predicted to arise owing to activity-induced Marangoni flow even if the particles are not self-propelled. Here, we test this prediction by employing a monolayer of spherically symmetric active [Formula: see text] particles located at an oil-water interface with or without addition of a nonionic surfactant. Due to the spherical symmetry, an individual particle does not self-propel. However, the gradients produced by the photochemical fuel degradation give rise to long-ranged Marangoni flows. For the case in which surfactant is added to the system, we indeed observe the emergence of collective motion, with dynamics dependent on the particle coverage of the monolayer. The experimental observations are discussed within the framework of a simple theoretical mean-field model.
对于位于流体界面的化学活性粒子单层，即使粒子不自推进，也预测会由于活性诱导的 Marangoni 流而产生集体动力学。在这里，我们通过在油-水界面上使用具有或不具有添加非离子表面活性剂的球形对称活性[Formula: see text]粒子单层来测试此预测。由于球形对称性，单个粒子不自推进。然而，光化学反应燃料降解产生的梯度导致长程 Marangoni 流动。对于向系统中添加表面活性剂的情况，我们确实观察到了集体运动的出现，其动力学取决于单层粒子的覆盖率。实验观察结果在简单的理论平均场模型框架内进行了讨论。
