Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 10617.
J Phys Chem B. 2010 Jun 24;114(24):8043-55. doi: 10.1021/jp1039157.
The influences of a boundary and the shape of a particle on its diffusiophoretic behavior are examined by considering the diffusiophoresis of a charged ellipsoid along the axis of an uncharged cylindrical pore filled with electrolyte solutions. The diffusiophoretic mobility of the particle under various conditions is evaluated through varying the particle aspect ratio, the size of the particle, the thickness of the double layer, the diffusivities of co-ions and counterions, and the level of the surface potential. Because the double-layer polarization, the electrophoresis effect, the boundary effect, and the electrical interaction between the particle and the co-ions outside the double layer all play a role, the diffusiophoretic behavior of the particle is complicated. For a fixed particle volume, the relative magnitude of the diffusiophoretic mobilities of particles of various shapes depends highly on the degree of the boundary effect. It is possible for a particle to migrate toward the low-concentration side, regardless of the level of the surface potential, which is not observed in the case of a sphere in a planar slit or in a spherical cavity.
通过考虑带电椭球体在充满电解质溶液的不带电圆柱孔轴线上的扩散泳行为，研究了边界和颗粒形状对其扩散泳行为的影响。通过改变颗粒的纵横比、颗粒的大小、双电层的厚度、共离子和反离子的扩散系数以及表面电势的水平，评估了颗粒在各种条件下的扩散泳迁移率。由于双电层极化、电泳效应、边界效应以及颗粒和双电层外的共离子之间的电相互作用都起作用，因此颗粒的扩散泳行为很复杂。对于固定的颗粒体积，各种形状的颗粒的扩散泳迁移率的相对大小高度依赖于边界效应的程度。即使在表面电势水平下，颗粒也有可能朝着低浓度侧迁移，这在平面狭缝或球形腔中的球体情况下是观察不到的。
