Electrophoresis of Colloids in Carreau Fluid at High Zeta Potential

• Main Authors: ChiaHsuan Tai, 戴嘉萱
• Other Authors: Keh-Chyang Lee
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/49677823492323154404

碩士 === 國立臺灣大學 === 化學工程學研究所 === 90 === In this study, we investigate theoretically the electrophoresis of spherical colloids suspended in Carreau fluid at arbitrary zeta potential. The effect of double layer polarization and the overlapping are taken into account. We use Carreau fluid model as the constitution equation of the electrolyte solution. Therefore, the flow field in the electrolyte solution is different from the typical Newtonian fluid. The pseudo-spectral method is used for solving the electrokinetic equation, which describes the electric field, the fluid field and the ion field. Among other observations, we find that as the zeta potential increases, the effect of double layer polarization dominate the electrophoresis behavior in this system at higher double layer. Moreover, for fixed surface potential, the higher the concentration of colloids the smaller the mobility. Other results show the effect of Carreau fluid, which represent the shear-thinning effect. For fixed surface potential, as n decrease and  increase the shear-thinning effect is more significant. Therefore, the mobility increases. At higher zeta potential, the difference between Newtonian fluid and Carreau fluid become more significant.