Counterion release and electrostatic adsorption
Phys. Rev. Lett., 84 (21):
4862--4865 (2000)Abstract
The effective charge of a rigid polyelectrolyte (PE) approaching an
oppositely charged surface is studied. The eases of a weak (annealed)
and strongly charged PE with condensed counterions (such as DNA)
are discussed. In the most interesting case of the adsorption onto
a substrate of low dielectric constant (such as a lipid membrane
or a mica sheet) the condensed counterions are and always released
as the PE approaches the substrate, because of the major importance
of the image-charge effect. For the adsorption onto a surface with
freely moving charges, the image-charge effect becomes less important
and full release is often expected.