Single and pairwise motion of particles near an ideally polarizable electrode.
Single and pairwise motion of particles near an ideally polarizable electrode.
复制标题
理想极化电极附近粒子的单次和成对运动。
DOI：
10.1021/la2017038
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
D. Prieve
中科院分区：
文献类型：
--
作者：
C. Wirth;Reza M. Rock;P. Sides;D. Prieve
研究了单颗粒纵向运动和成对横向运动，同时通过通常指向靠近颗粒的电极的振荡电场来激发颗粒。电极在不足以驱动电化学反应的电位范围内极化，该范围称为“理想极化区域”。尽管不存在电化学反应，但颗粒的运动在质量上取决于电解质的选择。当没有明确排除电化学反应时，颗粒高度和电场之间的相位角θ与激发过程中颗粒的分离或聚集相关。粒子响应的简单简谐振子模型（包括胶体力和流体动力，以及之前在本文中未引用的巴塞特力）显示了 θ 如何在低频下从 0° 增加，在~100 Hz 下跨越 90°，然后随着频率增加而增加到 180°。该模型捕捉了本文和早期作品中讨论的实验观察的本质。这是该问题的第一个先验预测。
Single-particle longitudinal motion and pairwise lateral motion was investigated while the particles were excited by an oscillating electric field directed normally to an electrode proximate to the particles. The electrode was polarized over a range of potential insufficient to drive electrochemical reactions, a range called the "ideally polarizable region". The particles' motion was qualitatively dependent on the choice of electrolyte despite the absence of electrochemical reactions. As when electrochemical reactions were not explicitly excluded, the phase angle θ between particle height and electric field correlated with the particles' separation or aggregation during excitation. A simple harmonic oscillator model of the particles' response, including colloidal and hydrodynamic forces and including the Basset force not previously cited in this context, showed how θ can increase from 0° at low frequencies, cross 90° at ∼100 Hz, and then increase to 180° as frequency was increased. The model captured the essence of experimental observations discussed here and in earlier works. This is the first a priori prediction of θ for this problem.