论文标题
剪切流中的自行式Janus胶体
Self-Propelled Janus Colloids in Shear Flow
论文作者
论文摘要
为了充分利用人造活性胶体的潜力，对包括外部流动在内的各种外部刺激的反应进行了研究。因此，在这项研究中，我们对悬浮在毛细管中的水性培养基中的SiO2-PT JANUS颗粒进行实验，受到不同的剪切流速。使用各种H2O2（燃料）浓度推动颗粒。对于特定的推进速度，随着剪切流的增加，观察到活动的Janus颗粒运动的运动转变从通常的随机活动运动到跨流线的优先运动，然后观察到沿流动的迁移。我们的分析表明，这些过渡是由壁W.R.T.附近的自我塑造引起的扭矩决定的。剪切引起的扭矩。有趣的是，我们发现只有当这些扭矩是可比的，粒子以某种方式对齐，以使它们在整个流线之间显着迁移。
To fully harness the potential of artificial active colloids, investigation of their response to various external stimuli including external flow is of great interest. Therefore, in this study, we perform experiments on SiO2-Pt Janus particles suspended in an aqueous medium in a capillary subjected to different shear flow rates. Particles were propelled using varied H2O2 (fuel) concentrations. For a particular propulsion speed, with increasing shear flow, a transition of motion of active Janus particles from the usual random active motion to preferential motion across stream-lines and then finally to migration along the flow, was observed. Our analysis revealed that these transitions are dictated by the torque due to the self-propulsion near wall w.r.t. shear-induced torque. Interestingly, we found that only when these torques are comparable, particles align in a manner such that they migrate significantly across the streamlines.
