Structural properties of charged diblock copolymer solutions
Service de Physique de l'Etat Condensé, C.E.A. Saclay,
91191 Gif-sur-Yvette Cedex, France
2 Service de Chimie Moléculaire, C.E.A. Saclay, 91191 Gif-sur-Yvette Cedex, France
3 Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
4 Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
5 Laboratoire Léon Brillouin, C.E.A. Saclay, 91191 Gif-sur-Yvette Cedex, France
Corresponding author: a email@example.com
Revised: 4 September 1997
Accepted: 9 October 1997
Published online: 15 January 1998
Aqueous micellar solutions of ionic/neutral block copolymers have been studied by light scattering, small angle neutron scattering and small angle X-ray scattering. We made use of a polymer comprised of a short hydrophobic block (polyethylene-propylene) PEP and of a long polyelectrolytic block (polystyrene-sulfonate) PSSNa which has been shown previously to micellize in water. The apparent polydispersity of these micelles is studied in detail, showing the existence of a few large aggregates coexisting with the population of micelles. Solutions of micelles are found to order above some threshold in polymer concentration. The order is liquid-like, as demonstrated by the evolution with concentration of the peak observed in the structure factor (), and the degree of order is found to be identical over a large range of concentrations (up to 20 wt%). Consistent values of the aggregation number of the micelles are found by independent methods. The effect of salt addition on the order is found to be weak.
PACS: 61.25.Hq – Macromolecular and polymer solutions; polymer melts; swelling / 83.70.Hq – Heterogeneous liquids: suspensions, dispersions, emulsions, pastes, slurries, foams, block copolymers, etc. / 61.20.Qg – Structure of associated liquids: electrolytes, molten salts, etc.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998