Jalilvand Zohreh, Notarmuzi Daniele, Córdova-Figueroa Ubaldo M, Bianchi Emanuela, Kretzschmar Ilona
Department of Chemical Engineering, City College of New York (CCNY), City University of New York (CUNY), 140th Street & Convent Avenue, New York, New York 10031, USA.
Institute for Theoretical Physics, Technische Universität Wien, Wiedner Hauptstraße 8-10, A-1040, Vienna, Austria.
Soft Matter. 2025 Jul 16;21(28):5773-5784. doi: 10.1039/d5sm00229j.
In this study, Brownian dynamics simulations are implemented to investigate the motion of a bottom-heavy Janus particle near a wall under varying shear flow conditions and at small Péclet (Pe) numbers. The stochastic motion of the Janus particle impacted by surface forces is described using a set of coupled Langevin equations that takes into account the Janus particle orientation. Interactions arising from surface potentials are found to depend on the separation distance between the Janus particle and the wall, the properties of the surfaces involved, and the thickness of the Janus particle cap. When shear flow is introduced in the system, the dynamical behavior of the Janus particle is also governed by the strain rate. Furthermore, the effect of friction on the dynamical behavior of the Janus particle under shear flow is investigated and reveals that the rotational motion of the Janus particle slows down slightly when the particle is close to the surface. In summary, we demonstrate the ability to utilize Brownian dynamics simulations to capture the rich dynamical behavior of a bottom-heavy Janus particle near a wall and under a range of shear flow conditions, cap thicknesses, and surface charges.
在本研究中，进行了布朗动力学模拟，以研究在不同剪切流条件下以及在小佩克莱特（Pe）数下，底部较重的Janus粒子在壁面附近的运动。利用一组考虑Janus粒子取向的耦合朗之万方程来描述受表面力影响的Janus粒子的随机运动。发现由表面势引起的相互作用取决于Janus粒子与壁面之间的分离距离、所涉及表面的性质以及Janus粒子帽的厚度。当在系统中引入剪切流时，Janus粒子的动力学行为也受应变率的支配。此外，研究了摩擦对剪切流下Janus粒子动力学行为的影响，结果表明当粒子靠近表面时，Janus粒子的旋转运动会略有减慢。总之，我们证明了利用布朗动力学模拟来捕捉底部较重的Janus粒子在壁面附近以及在一系列剪切流条件、帽厚度和表面电荷下丰富的动力学行为的能力。
