Diffusiophoretic Phenomenon of a Charge-Regulating Porous Particle Normal to a Solid Plane

• Main Authors: Hsin-Yuan Lee, 李心源
• Other Authors: Eric Lee
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/gzkn7t

碩士 === 國立臺灣大學 === 化學工程學研究所 === 106 === Diffusiophoresis of a charge-regulating porous particle normal to a conducting plane is investigated theoretically in this study. Due to the configuration envolving spherical particle and planar boundary, the system characterized by bipolar coordinates. The coupled electrokinetic equations are solved linearly with a pseudo-spectral method based on Chebyshev polynomials. Also, Newton-Ralphson iteration scheme are adopted here for solution. Electrolyte concentration, dissociation constant, pH, particle transmittance and the distance between particle and plane are discussed as variables in the study. We find that the charge density of the porous particle will increase as the electrolyte concentration and counterion condensation increases. However, while the electrolyte concentration is low, effect of the diffusion potential dominants which leads particle to negative direction. Otherwise, the polarization effect will take place and goes to positive direction. We also find that the presence of solid plane will increase the particle charge density as well as particle mobility. The plane will deform the electric double layer and redistribute the electrolye ions, which builds an induced electric field toward positive or negative direction, depends on the electrolyte concentration and pH.