Dynamic Electrophoresis and Dielectrophoretic Phenomena of a porous sphere in an Electrolyte Solution
| Autor: | Xiang-Xu Wang, 王祥旭 |
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| Rok vydání: | 2016 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 The electrokinetic behavior of porous sphere is investigated, including dynamic electrophoresis and dielectrophoresis (DEP). Many bioparticles such as potein, DNA and RNA are belonged to polyelectrolyte which has great application in biomedical field and is well modeled as charged porous spheres. So it is important to know how to control the motion of these particles in the small scale system efficiently. Compared with electrophoresis, dynamic electrophoresis is driven by alternating current (AC), which has advantage of convenience of measure and prevention of Joule heating effect. To manipulate particle more precisely, dielectrophoresis(DEP) has a great performance in trapping and separation. Dielectrophoresis, the migration of a dielectric in a non-uniform electric field, has grabbed a great deal of interest in micro/nano-technologies such as microfluidic devices, biomaterial and lab-on-a-chip. However, relevant theoretical researches are still limited. In addition, there exist various kinds of particles other than traditional rigid one, including polyelectrolyte and biological cells, which cannot be modeled as rigid particles. The electrophoretic motion seriously influences the electric double layer and thus polarizability. Positive correlation between dipole coefficient and the particle’s mobility is found because of double layer polarization. DEP has a powerful ability to manipulate particle precisely, but needs a series of experimental tests to fit our demand. So we will study dipole coefficient, which is the most important parameter of DEP, to help to increase experimental efficiency. We use electrokinetic model to describe a charge porous sphere behavior in an electrolyte solution and subjected to an alternating electric field. Dipole coefficient is calculated as a function of the double-layer thickness, charge density, friction coefficient, permittivity and the electric-field frequency. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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