Boundary effects on osmophoresis: motion of a vesicle normal to a plane wall
Resource
Chemical Engineering Science 48 (3): 609-616
Journal
Chemical Engineering Science
Journal Volume
48
Journal Issue
3
Pages
609-616
Date Issued
1993
Date
1993
Author(s)
Yang, Fong Ru
Abstract
An exact analytical study is presented for the osmophoresis of a spherical vesicle in a constant solute concentration gradient normal to a plane wall. The vesicle, which is a body of fluid enveloped by a continuous semipermeable membrane, may hold arbitrary solute in it. The conservative equations for the solute species and fluid momentum applicable to the system are solved in the quasi-steady situation using spherical bipolar coordinates and the osmophoretic velocity of the vesicle is calculated for various cases. Interestingly, the osmophoretic mobility of the vesicle increases monotonically as the vesicle approaches the wall. The interaction between the boundary and the vesicle can be very strong when the surface-to-surface spacing gets close to zero. Also, the boundary effect on the fluid flow pattern in osmophoresis differs significantly from that of the corresponding sedimentation problems. © 1992.
Type
journal article