| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 100 === Electrophoresis of two charged porous spheres moving along their line of centers is investigated theoretically, where overlapping and polarization effect of electric double layers are both taken into account. The thickness of electric double layer and fixed charge density of porous spheres are arbitrary. The coupling equations of electric potential, ion concentration, and flow field are linearized by assuming that the external electric field is weak. A pseudo-spectral method based on Chebyshev polynomials is applied to numerically solve the resulting electrokinetic equations.
To clarify the effect of particle interactions on the electrophoretic mobility, the effects of key parameters are examined such as the double layer thickness, fixed charge density, friction coefficient of porous particles, and surface distance between particles. The most curial finding, besides the non-zero interactions between identical particles, is that particle mobility decreases as double layer of two particles touched due to the polarization effect on the role of electric interactions. More interesting findings is that particle mobility may lower than that of the single one when high double layer overlapping is consideration. These findings was not investigated in the corresponding studies of two particle interactions where overlapping of electric double layers or polarization effect is neglected, indicating the importance of these two factors. Particle interactions between two charged porous particles can be used to describe homogeneous concentrated suspensions of polyelectrolyte in a fundamental aspect of colloid science.
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