Electrooptic Behavior and Structure of Novel Polymer-Vesicle Hybrids

It has been previously shown that polymerization of styrene in DODAB vesicles gives rise to the formation of unique parachute-like structures in which a polymer bead is confined to the bilayer at one pole of the vesicle. In this paper, quantitative data on the size and the shape of these hybrid particles and of the bare DODAB vesicles are obtained by combination of cryo-TEM, transient electrooptic birefringence (Kerr effect), and dynamic light scattering. Also, this study qualitatively assesses the influence of the confined polymer bead on the electrooptic behavior. It turns out that the presence of the bead gives rise to a special response in the transient electrooptic birefringence, typical of the existence of permanent dipoles. Unlike other vesicles, the DODAB vesicles and the polymer/vesicle hybrids do not display a deformation step in their electrooptic response. As such, these particles act as rigid particles under the action of an electric field. The thermal behavior of the DODAB templates and parachutes is investigated and explained in terms of intrinsic vesicle properties