Electrophoretic Motion of a Prolate Spheroid in Electro-osmotic Flow Developed in a Flat Cell.
Electrophoretic motion is analyzed for a neutrally buoyant, non-Brownian prolate spheroid suspended in an electro-osmotic flow developed in a flat microelectrophoresis cell. Neglecting the double-layer deformation, the trajectory and orientation of the spheroid is computed to assess the significance of particle motion in a lateral direction during an electrophoresis experiment. The double-layer thickness of the spheroid is arbitrary. In a closed microelectrophoresis system the electro-osmosis results in a parabolic flow field. During a short period of time (several seconds) the spheroid may deviate significantly in a lateral direction from a straight path parallel to the applied electric field. During a longer period of time (several minutes) the spheroid undergoes a sinuous motion in which it translates periodically back and forth across a straight path along the main flow direction. The spheroid may also translate along a closed trajectory. In all cases the orientation of the spheroid follows the equation for Jeffery orbit. Copyright 1999 Academic Press.
Yoon
BJ
Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea