Pairing-induced motion of source and inert particles driven by surface tension
Pairing-induced motion of source and inert particles driven by surface tension
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由表面张力驱动的源粒子和惰性粒子的配对引起的运动
DOI：
10.1103/physreve.106.024604
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发表时间：
2022
影响因子：
2.4
通讯作者：
Sumino Yutaka
中科院分区：
文献类型：
--
作者：
Ishikawa Hiroaki;Koyano Yuki;Kitahata Hiroyuki;Sumino Yutaka
我们从实验和理论上研究了一对源和惰性粒子通过浓度场相互作用的系统。实验系统包括作为源粒子的樟脑圆盘和作为惰性粒子的金属垫圈。两者都漂浮在不同浓度的甘油水溶液上，其中甘油改变水相的粘度。由于吸引的横向毛细力，颗粒形成一对。当樟脑盘在水表面散布表面活性分子时，樟脑盘和金属垫圈在表面张力梯度的驱动下一起移动。垫圈位于樟脑盘的前面，在它们的运动过程中保持距离恒定，我们称之为配对诱导运动。随着水相中甘油浓度的变化，配对诱导的运动表现出圆形和直线运动之间的过渡。数值计算使用的模型，认为由表面张力梯度和横向毛细管相互作用所造成的力再现了所观察到的配对诱导运动的过渡。此外，这一转变与通过关于粒子速度展开得到的约化动力系统的线性稳定性分析的结果一致。我们的结果表明，粒子速度的影响不能忽略，以描述通过浓度场的相互作用。
We experimentally and theoretically investigate systems with a pair of source and inert particles that interact through a concentration field. The experimental system comprises a camphor disk as the source particle and a metal washer as the inert particle. Both are floated on an aqueous solution of glycerol at various concentrations, where the glycerol modifies the viscosity of the aqueous phase. The particles form a pair owing to the attractive lateral capillary force. As the camphor disk spreads surface-active molecules at the aqueous surface, the camphor disk and metal washer move together, driven by the surface tension gradient. The washer is situated in the front of the camphor disk, keeping the distance constant during their motion, which we call a pairing-induced motion. The pairing-induced motion exhibited a transition between circular and straight motions as the glycerol concentration in the aqueous phase changed. Numerical calculations using a model that considers forces caused by the surface tension gradient and lateral capillary interaction reproduced the observed transition in the pairing-induced motion. Moreover, this transition agrees with the result of the linear stability analysis on the reduced dynamical system obtained by the expansion with respect to the particle velocity. Our results reveal that the effect of the particle velocity cannot be overlooked to describe the interaction through the concentration field.