Electrophoresis of a Rigid Sphere in a Carreau Fluid Normal to a Large Charged Disk
Resource
The Journal of Physical Chemistry B 111 (43): 12351-12361
Journal
The Journal of Physical Chemistry B
Journal Volume
111
Journal Issue
43
Pages
12351-12361
Date Issued
2007
Date
2007
Author(s)
Abstract
The electrophoresis of a rigid sphere in a Carreau fluid normal to a large disk is analyzed theoretically under the conditions of low surface potential and weak applied electric field. Previous analyses are extended to the case where a disk can be charged, and a more realistic electrostatic force formula is applied. We show that the qualitative behavior of a sphere depends largely on its distance from a disk, the thickness of double layer, and the nature of a fluid. In general, the presence of a disk has the effect of increasing the conventional hydrodynamic drag on a sphere, and a decrease in the thickness of the double layer surrounding a sphere has the effect of enhancing the shear-thinning effect. However, this might not be the case if a sphere is uncharged and a disk is charged, where the osmotic pressure field and the induced charge on the sphere surface can be significant. The shear-thinning effect is important only if the thickness of double layer is sufficiently thick. This result can play a significant role in practice such as in electrophoretic deposition, where the deposition electrode is charged and the fluid medium is usually of shearing-thinning nature.
Type
journal article
File(s)![Thumbnail Image]()
Loading...
Name
93.pdf
Size
577.14 KB
Format
Adobe PDF
Checksum
(MD5):943717110cb1309eae411bb6cb3032ed