Shelke Yogesh, Srinivasan N R, Thampi Sumesh P, Mani Ethayaraja
Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering , Indian Institute of Technology Madras , Chennai 600036 , India.
Langmuir. 2019 Apr 2;35(13):4718-4725. doi: 10.1021/acs.langmuir.9b00081. Epub 2019 Mar 21.
Nonspherical self-propelling colloidal particles offer many possibilities for creating a variety of active motions. In this work, we report on the transition from linear to circular motion of active spherical-cap particles near a substrate. Self-propulsion is induced by self-diffusiophoresis by catalytic decomposition of hydrogen peroxide (HO) on one side of the particle. Asymmetric distribution of reaction products combined with the asymmetric shape of the particle gives rise to two types of motions depending upon the relative orientation of the particle with respect to the underlying substrate. At a low concentration of HO, linear active motion is observed, whereas increasing the HO concentration leads to persistent circular motion. However, the speed of self-propulsion is nearly independent of the size of the particle. The study demonstrates the use of nonspherical particles to create linear and circular motion by varying the fuel concentration.
非球形自推进胶体粒子为产生各种主动运动提供了多种可能性。在这项工作中，我们报道了活性球冠形粒子在靠近基底时从线性运动到圆周运动的转变。粒子一侧的过氧化氢（H₂O₂）催化分解通过自扩散电泳诱导自推进。反应产物的不对称分布与粒子的不对称形状相结合，根据粒子相对于下层基底的相对取向产生两种类型的运动。在低浓度的H₂O₂下，观察到线性主动运动，而增加H₂O₂浓度会导致持续的圆周运动。然而，自推进速度几乎与粒子大小无关。该研究表明通过改变燃料浓度利用非球形粒子来产生线性和圆周运动。
