  We report on the formation of colloidal complexes resulting from the
electrostatic self-assembly of polyelectrolyte-neutral block copolymers and
oppositely charged surfactants. The copolymers investigated are asymmetric and
characterized by a large neutral block. Using light, neutron and x-ray
scattering experiments, we have shown that the colloidal complexes exhibit a
core-shell microstructure. The core is described as a dense and disordered
micro-phase of micelles connected by the polyelectrolyte blocks, whereas the
shell is a diffuse brush made from the neutral chains. Colloidal complexes with
core-shell structures resemble the well-known amphiphilic block copolymer
micelles. The self-assembly mechanism is however different here. It is based on
the complexation between opposite charges. This mechanism has recently
attracted much interest because it allows to associate components of different
nature, such as organic and inorganic or synthetic and biological.
