Eur. Phys. J. E 4, 45-50
Diblock copolymers adsorbed at a water-oil interface
P. Omarjee1, P. Hoerner2, G. Riess2, V. Cabuil3 and O. Mondain-Monval1.1 Centre de Recherche Paul Pascal-CNRS, Av. A. Schweitzer, 33600 Pessac, France
2 Ecole Nationale Supérieure de Chimie de Mulhouse, 3 rue A. Werner, 68093 Mulhouse Cedex, France
3 Laboratoire LI2C - Colloïdes Magnétiques, Université P. et M. Curie, 4 Place Jussieu, 75252 Paris, Cedex 05, France
mondain@crpp.u-bordeaux.fr
(Received 5 May 2000 and Received in final form 6 July 2000)
Abstract
We probe the conformation of a diblock copolymer layer
adsorbed at the surface of water-in-oil emulsion droplets at
various concentration of a molecular surfactant. The diblock
copolymer is made of a hydrophobic polybutadiene part linked to a
hydrophilic polyethylene oxide one. The measure provides the
equilibrium thickness of the polymer layer that is obtained with
two different techniques, i.e. dynamic light scattering
and force measurements. The structure of the layer is shown to
change from a "mushroom"conformation in which the adsorbed
chains form independent Gaussian coils to a conformation where they
interact and extend in the continuous phase. The transition from
one regime to the other is progressive as the ratio
surfactant/polymer bulk concentration varies.
82.70.Dd - Colloids.
36.20.-r - Macromolecules and polymer molecules.
68.10.-m - Fluid surfaces and fluid-fluid interfaces.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001