Simultaneous action of electric fields and nonelectric forces on
a polyelectrolyte: Motion and deformation
Physical Review Letters, 76 (20):
3858--3861 (May 1996)Abstract
We describe the deformation and drift of a charged polymer in solution
under the simultaneous action of an electric field and a nonelectric
force. This should be of interest for current micromanipulation experiments
on DNA fragments and for electrophoretic separation methods. Our
description is qualitatively different from existing theories. The
main results are (i) that the force to hold a polyelectrolyte immobile
in an electric field E(infinity) is proportional to its 3D size (and
not to its curvilinear length or total charge), and (ii) that its
deformation is then essentially identical to that in a purely hydrodynamic
uniform flow of velocity V = mu(el)E(infinity) (mu(el) is the electrophoretic
mobility of the polyelectrolyte).