Separation of polystyrene microbeads using dielectrophoretic/gravitational field-flow-fractionation.
Separation of polystyrene microbeads using dielectrophoretic/gravitational field-flow-fractionation.
复制标题
DOI：
10.1016/s0006-3495(98)77975-5
复制
发表时间：
1998-05
影响因子：
3.4
通讯作者：
Xiao-Bo Wang;Jody V. Vykoukal;Frederick F. Becker;P. Gascoyne
中科院分区：
文献类型：
--
作者：
Xiao-Bo Wang;Jody V. Vykoukal;Frederick F. Becker;P. Gascoyne
介绍了聚苯乙烯（PS）微珠介质电泳/重力场-流分馏（DEP/G-FFF）体系的表征。演示了不同表面功能化（COOH和非COOH）和不同尺寸（直径6、10和15μm）的PS珠的分离。为了研究影响分离性能的因素，确定了颗粒洗脱时间与颗粒悬浮液电导率、流体流速、外加电场频率和电压的关系。用已有的理论模型对实验数据进行了分析，发现理论与实验吻合较好。结果表明，PS珠的分离是基于其有效介电性能的差异。通过DEP和重力的平衡，将具有不同介电性质的颗粒定位在薄腔内流体流动剖面的不同高度，在流体流动的影响下以不同的速度输送，从而分离。为了探索流体动力（HD）升力效应，在不施加DEP场的情况下，测定了PS珠的速度与分离室中流体流速的关系。在这种情况下，粒子平衡高度位置仅由HD升力和重力的平衡决定。结果表明，在本文所报道的实验条件下，DEP力是控制颗粒平衡高度的主要因素，HD升力对DEP/G-FFF运行的影响较小。最后，讨论了不同实验参数对DEP/G-FFF分离性能的影响。
The characterization of a dielectrophoretic/gravitational field-flow-fractionation (DEP/G-FFF) system using model polystyrene (PS) microbeads is presented. Separations of PS beads of different surface functionalization (COOH and none) and different sizes (6, 10, and 15μm in diameter) are demonstrated. To investigate the factors influencing separation performance, particle elution times were determined as a function of particle suspension conductivity, fluid flow rate, and applied field frequency and voltage. Experimental data were analyzed using a previously reported theoretical model and good agreement between theory and experiment was found. It was shown that separation of PS beads was based on the differences in their effective dielectric properties. Particles possessing different dielectric properties were positioned at different heights in a fluid-flow profile in a thin chamber by the balance of DEP and gravitational forces, transported at different velocities under the influence of the fluid flow, and thereby separated. To explore hydrodynamic (HD) lift effects, velocities of PS beads were determined as a function of fluid flow rate in the separation chamber when no DEP field was applied. In this case, particle equilibrium height positions were governed solely by the balance of HD lift and gravitational forces. It was concluded that under the experimental conditions reported here, the DEP force was the dominant factor in controlling particle equilibrium height and that HD lift force played little role in DEP/G-FFF operation. Finally, the influence of various experimental parameters on separation performance was discussed for the optimization of DEP/G-FFF.