论文标题
可调节疏水性对流量下Janus颗粒的集体流体动力学的影响
Effects of Tunable Hydrophobicity on the Collective Hydrodynamics of Janus Particles under Flows
论文作者
论文摘要
具有非平衡自我组织的活跃胶体系统是生物学长期挑战的领域。为了了解如何使用流体动力流来积极控制Janus颗粒（JPS）的自组装，我们使用了最近开发的模型，用于悬浮在粘性背景流中的两亲智的JP的多体水动力学（JFM，941，2022）。我们研究了各种形态是如何通过调整JP溶剂界面的疏水分布而产生的。我们发现JP组装成Uni-Lamella，多层层和横纹结构。要引入动力学，我们包括线性剪切流量和稳定的泰勒绿色混合流，并根据JP之间的疏水相互作用来测量JP颗粒的集体动力学，（a）自由能，（（b）以降级JP的顺序参数，以捕获JP的订购，（c）捕获降低的降级参数。我们表征了JP结构的有效材料特性，并发现单层结构在剪切流下增加了方向顺序，多层结构的表现为剪切稀薄的液体，并且横纹结构具有屈服应力。这些数值结果提供了对具有相似自组织的非平衡活性生物系统动态控制的见解。
Active colloidal systems with non-equilibrium self-organization is a long-standing, challenging area in biology. To understand how hydrodynamic flow may be used to actively control self-assembly of Janus particles (JPs), we use a model recently developed for the many-body hydrodynamics of amphiphilic JPs suspended in a viscous background flow (JFM, 941, 2022). We investigate how various morphologies arise from tuning the hydrophobic distribution of the JP-solvent interface. We find JPs assembled into uni-lamella, multi-lamella and striated structures. To introduce dynamics, we include a linear shear flow and a steady Taylor-Green mixing flow, and measure the collective dynamics of JP particles in terms of their (a) free energy from the hydrophobic interactions between the JPs, (b) order parameter for the ordering of JPs in terms of alignment of their directors, and (c) strain parameter that captures the deformation in the assembly. We characterize the effective material properties of the JP structures and find that the uni-lamellar structures increases orientation order under shear flow, the multilamellar structure behaves as a shear thinning fluid, and the striated structure possesses a yield stress. These numerical results provide insights into dynamic control of non-equilibrium active biological systems with similar self-organization.
