Positive Dielectrophoretic Mobilities of Single Microparticles Enhanced by the Dynamic Diffusion Cloud of Ions
Positive Dielectrophoretic Mobilities of Single Microparticles Enhanced by the Dynamic Diffusion Cloud of Ions
复制标题
离子动态扩散云增强单个微粒的正介电泳迁移率
作者：
S. Tsukahara;A. Sakamoto;H. Watarai
用四极微电极研究了单一聚苯乙烯-羧酸酯微球和聚苯乙烯微球的介电电泳行为。对于在低频区域（≤10 kHz）观察到的聚苯乙烯-羧酸盐颗粒的正介电电泳（DEP），DEP迁移率系数（α）几乎与交流电压的平方（Urms，均方根）成正比，正如标准理论所预期的那样。α值不依赖于粒子半径（re），但依赖于电解质的种类，顺序为HCl <$KCl <$KOH ≥四丁基氯化铵，表明H+对α值有特定的增强作用。由于这一观测结果与标准理论不符，我们引入了Debye型函数的DEP半径（rDEP）来代替粒子半径，以拟合低频区域的观测α值。正介电电泳行为由负电荷粒子的表面电导率和rDEP的函数再现。至于负DEP中观察到的较高频率的r…
Dielectrophoretic behavior of single polystyrene-carboxylate microparticles and polystyrene microparticles was studied with a quadrupole microelectrode. For positive dielectrophoresis (DEP) of polystyrene-carboxylate particle observed in the lower frequency region (≤10 kHz), a DEP mobility coefficient (α) was almost proportional to the square of ac voltage (Urms, root mean square), as was expected from standard theories of DEP. The α values did not depend on the particle radius (re), but depended on the kind of electrolyte in the order HCl ≫ KCl ≈ KOH ≥ tetrabutylammonium chloride, showing a specific enhancement by H+. Since this observation was against the standard theories, we introduced a DEP radius (rDEP) of a Debye-type function instead of the particle radius to fit the observed α values in the lower frequency region. The positive DEP behaviors were reproduced by a function of rDEP and the surface conductivity of the negatively charged particles. As for negative DEP observed in the higher frequency r...