Eur. Phys. J. E 6, 109-115 (2001)
Counterion distribution in a spherical charged sparse brush
F. Muller1, P. Fontaine2, M. Delsanti3, L. Belloni3, J. Yang4, Y.J. Chen4, 5, J.W. Mays4, P. Lesieur2, M. Tirrell6 and P. Guenoun11 Service de Physique de l'Etat Condensé, CEA Saclay, F-91191 Gif-sur-Yvette Cedex, France
2 Laboratoire pour l'Utilisation du Rayonnement Electromagnétique, Centre Universitaire Paris-Sud, bât. 209D, BP 34, 91898 Orsay Cedex, France
3 Service de Chimie Moléculaire, CEA Saclay, F-91191 Gif-sur-Yvette Cedex, France
4 Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
5 Exxon Chemical Co., Baytown, TX 77522, USA
6 Departments of Chemical Engineering and of Materials, University of California, Santa Barbara, CA 93106, USA
guenoun@drecam.saclay.cea.fr
(Received 14 February 2001 and Received in final form 2 May 2001)
Abstract
The counterion distribution within a spherical polyelectrolyte sparse brush
was measured by small-angle X-ray scattering using contrast variation with
different counterions by means of ion dialysis. The brush was made by
self-association of charged diblock copolymers. Thanks to the contrast
variation method, we were able to separate the signal due to the monomers
and the signal due to the counterions. At a small length scale, it is
demonstrated that the system behaves as independent charged rods whose
counterion distribution follows the Poisson-Boltzmann model.
83.80.Uv - Block copolymers.
82.35.Rs - Polyelectrolytes.
61.10.Eq - X-ray scattering (including small-angle scattering).
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001