Electrophoresis of polyelectrolytes with partial drainage

The electrophoretic velocity of a uniformly charged porous sphere in a salt solution is considered to be composed of three contributions. These are: a motion caused by that part of the charge which is exactly compensated by counter‐ions within the porous sphere. a motion caused by the net charge of the porous sphere. a motion caused by the counter‐ions outside the sphere. The influence of relaxation is left out of consideration. The presence of the counter‐ions is shown to lead to a relatively high degree of draining. In solutions of high ionic strength, where the porous sphere model fails, polyelectrolyte coils are shown to be freely drained and the application of Henry's theory of electrophoresis of a cylindrical rod is discussed.