Rodlike Behavior of Polyelectrolyte Brushes

P. Guenoun; F. Muller; M. Delsanti; L. Auvray; Y. J. Chen; J. W. Mays; M. Tirrell

doi:10.1103/PhysRevLett.81.3872

Rodlike Behavior of Polyelectrolyte Brushes

P. Guenoun, F. Muller, M. Delsanti, L. Auvray, Y. J. Chen, J. W. Mays, and M. Tirrell

Phys. Rev. Lett. 81, 3872 – Published 2 November 1998

Abstract

Spherical charged brushes are studied in the form of block copolymer micelles. These copolymers are diblocks made of one deuterated, highly charged block and of one protonated, hydrophobic block. Neutron scattering with contrast matching enables us to probe selectively the structure of the arms of the charged corona of the micelles. A near-perfect rodlike behavior (scattered intensity $\sim q^{- 1}$ ) of the arms is observed at all salt concentrations above an onset in wave vector $q_{0}$ , which increases with salt concentration above a threshold. Results are strikingly different from what is observed for linear polyelectrolytes, since charged brushes appear very weakly sensitive to the addition of salt.

Received 17 March 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.3872

Authors & Affiliations

P. Guenoun¹, F. Muller^1,*, M. Delsanti², L. Auvray³, Y. J. Chen^4,†, J. W. Mays⁴, and M. Tirrell⁵

¹Service de Physique de l'Etat Condensé, CEA Saclay, 91191 Gif sur Yvette Cedex, France
²Service de Chimie Moléculaire, CEA Saclay, 91191 Gif sur Yvette Cedex, France
³Laboratoire Léon Brillouin, CEA Saclay, 91191 Gif sur Yvette Cedex, France
⁴Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294
⁵Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455

^*Also at Université de la Rochelle, 23 Av. A. Einstein, F-17000 La Rochelle Cedex 9, France.
^†Present address: Exxon Chemical Co., Baytown, TX 77522.