Fagan Jeffrey A, Sides Paul J, Prieve Dennis C
Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Langmuir. 2006 Nov 21;22(24):9846-52. doi: 10.1021/la060899j.
A rectified electroosmotic flow mechanism and its expression in a quantitative model account for the net lateral motion of colloidal particles above a uniform planar electrode in an alternating electric field that drives a faradaic reaction on the electrode surface. Specific comparison to published particle doublet trajectories at 100 Hz in sodium hydroxide and sodium bicarbonate electrolytes demonstrates that the model quantitatively agrees with the experimental doublet trajectories when only independently measurable parameters are employed. This model reproduces the experimental signatures of the published particle pair motion at 100 Hertz: dependence of the direction of motion on the electrolyte, order of magnitude of the interparticle velocity, invariance of the lateral motion to changes in the particle zeta potential, and observed steady separation between particles that otherwise tend to aggregate. The model is expected to apply up to approximately 1 kHz, at which essentially all of the alternating current flows through the double-layer capacitance and not the faradaic reaction.
一种整流电渗流机制及其在定量模型中的表达解释了在交变电场中，均匀平面电极上方的胶体颗粒的净横向运动，该交变电场驱动电极表面的法拉第反应。与已发表的在氢氧化钠和碳酸氢钠电解质中100Hz下颗粒双峰轨迹的具体比较表明，当仅采用独立可测量参数时，该模型在定量上与实验双峰轨迹一致。该模型再现了已发表的100赫兹下颗粒对运动的实验特征：运动方向对电解质的依赖性、颗粒间速度的数量级、横向运动对颗粒zeta电位变化的不变性，以及观察到的原本倾向于聚集的颗粒之间的稳定分离。预计该模型可应用至约1kHz，在该频率下，基本上所有交流电都通过双层电容而非法拉第反应。
