Dynamic polarization of a charged colloid in an oscillating electric field
Dynamic polarization of a charged colloid in an oscillating electric field
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带电胶体在振荡电场中的动态极化
DOI：
10.1080/00268976.2015.1059510
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
and Ryoichi Yamamoto
中科院分区：
文献类型：
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作者：
Chunyu Shih;John J. Molina;and Ryoichi Yamamoto
采用光滑剖面法直接数值模拟电解质溶液中带电胶体的动力学行为。我们计算了一个单一的胶体粒子在交流电场下的复极化率，其中的极化是由胶体的zeta电位，离子的扩散常数，双电层的厚度，和交流电场的频率的影响。两个动态不同的制度进行了观察，这取决于所施加的频率，具体地说，它是快还是慢于离子扩散速率超过胶体大小。目前的结果表明，非常好的协议与麦克斯韦-瓦格纳-O 'Konski（MWO）理论和标准电动理论的所有频率制度提供的zeta电位低。对于具有高zeta电位的高电荷粒子，标准电动力学模型在所有频率范围内都与目前的结果吻合得很好。在中间制度，观察与MWO理论的差异，因为它忽略了双电层的变形。
The dynamical behaviour of a charged colloid in an electrolyte solution is studied using direct numerical simulations via the smoothed profile method. We calculated the complex polarisability of a single colloidal particle under an AC electric field, where the polarisation is affected by the zeta potential of the colloid, the diffusion constant of the ions, the thickness of the electric double layer, and the frequency of the AC field. Two dynamically distinct regimes were observed depending on the applied frequency, specifically, on whether it is faster or slower than the ionic diffusion rate over the colloidal size. The present results showed very good agreements with the Maxwell–Wagner–O’Konski (MWO) theory and standard electrokinetic theories for all frequency regimes provided the zeta potential is low. For highly charged particles with high zeta potential, the standard electrokinetic models agree well with the present results for all frequency regimes. In the intermediate regimes, differences are observed with the MWO theory, as it ignores the deformation of the electric double layer.