Department of Applied Chemistry and Biotechnology, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan.
Department of Basic Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
J Colloid Interface Sci. 2018 Feb 1;511:184-192. doi: 10.1016/j.jcis.2017.09.099. Epub 2017 Sep 28.
The existence of a surface tension difference and a surface flow around self-propelled objects, such as camphor boats, has been confirmed by many studies. However, the interactions in the collective motion of several camphor boats have not been explicitly discussed. Here, a model system of two camphor boats was investigated for the first time from the viewpoint of surface tension and surface flow.
The behavior of one fixed boat and one movable boat on a sodium dodecylsulfate aqueous solution in an oval track has been studied as a model system of two-body interactions. The surface tension around the movable boat was measured using the non-invasive, double-beam quasi-elastic laser scattering method. The Marangoni surface flow was quantitatively estimated using a mock boat in order to evaluate the net repulsive interaction between the two boats.
We succeeded in controlling the motion of the two camphor boats by varying the boat characteristics and the surfactant concentration. The balance/unbalance between the surface tension distribution and the surface flow around the boats was found to drive two different behavior modes: stationary and oscillatory. These results allow us to gain further insight into the dynamics of the interactions in the collective behavior of autonomous inanimate objects.
许多研究已经证实，自推进物体（如樟脑船）周围存在表面张力差和表面流动。然而，几个樟脑船的集体运动中的相互作用尚未明确讨论。在这里，首次从表面张力和表面流动的角度研究了两个樟脑船的模型系统。
作为双体相互作用的模型系统，研究了在椭圆形轨道上的一个固定船和一个可动船在十二烷基硫酸钠水溶液中的行为。使用非侵入式双光束准弹性激光散射法测量了可动船周围的表面张力。使用模拟船定量估计了马兰戈尼表面流，以评估两船之间的净排斥相互作用。
我们成功地通过改变船的特性和表面活性剂浓度来控制两个樟脑船的运动。发现船周围的表面张力分布和表面流之间的平衡/不平衡驱动了两种不同的行为模式：静止和振荡。这些结果使我们能够更深入地了解自主无生命物体集体行为中相互作用的动力学。
