Suspensions of chemically powered self-propelled colloidal particles are examples of active matter systems with interesting properties. While simple spherical Janus particles are often studied, it is known that geometry is important and recent experiments have shown that chemically active torus-shaped colloids behave differently from spherical colloids. In this paper, coarse-grained microscopic simulations of the dynamics of self-diffusiophoretic torus colloids are carried out in bulk solution in order to study how torus geometric factors influence their active motion. The concentration and velocity fields are key ingredients in self-diffusiophoretic propulsion, and the forms that these fields take in the colloid vicinity are shown to be strong functions of torus geometric parameters such as the torus hole size and thickness of the torus tube. This work utilizes a method where self-diffusiophoretic torus colloids with various geometric and dynamical characteristics can be built and studied in fluid media that include chemical reactions and fluid flows. The model can be used to investigate the collective properties of these colloids and their dynamics in confined systems, topics that are of general importance for applications that use colloidal motors with complex geometries.

中文翻译：

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自推式环形胶体。

具有化学动力的自推进胶体颗粒的悬浮液是具有有趣特性的活性物质系统的示例。尽管经常研究简单的球形Janus颗粒，但众所周知几何形状很重要，最近的实验表明，化学活性圆环状胶体的行为不同于球形胶体。在本文中，在散装溶液中进行了自扩散环面胶体动力学的粗粒度微观模拟，以研究环面几何因素如何影响其主动运动。浓度场和速度场是自扩散荧光推进中的关键因素，这些场在胶体附近采取的形式被证明是圆环几何参数（例如圆环孔尺寸和圆环管厚度）的强函数。这项工作利用一种方法，可以在包括化学反应和流体流动的流体介质中构建和研究具有各种几何和动力学特性的自扩散环氧化物胶体。该模型可用于研究这些胶体的集体性质及其在密闭系统中的动力学，这些主题对于使用具有复杂几何形状的胶体电动机的应用具有普遍意义。