Polymerization in Polymerizable Vesicle Bilayer Membranes

Polymerization reactions in lyotropic liquid crystalline phases have opened the way to the development of many novel materials. Inter alia, the two-dimensional self-assembly of amphiphiles in vesicle bilayers has attracted considerable interest as an ordered reaction medium. In this study we follow three different routes to polymerize within vesicle bilayer membranes with a view to preparing novel vesicle−polymer colloids. First, we study the vesicle formation and the polymerization of functional amphiphiles carrying one or two styryl groups. A combination of characterization techniques gives insights into bilayer properties, polymerization kinetics, and vesicle morphology of these (polymerized) vesicles. On the basis of this reference system, we explore the copolymerization of monomers inserted in the matrix of polymerizable amphiphiles. On the basis of kinetic and morphological data we prove that the copolymerization is viable if the polymerizable moieties are adequately chosen with respect to reactivity and location within the amphiphile matrix. Extremely deformed, albeit stable, vesicles are induced by cross-linking inserted monomers with monofunctional amphiphiles. In a last step, we attempt the synthesis of two-dimensional interpenetrating networks employing the previously polymerized amphiphile networks as templates. The cross-linking of divinylbenzene within cross-linked membranes affords peculiar orange-skin-like bilayer morphologies and gives evidence of the feasibility of the concept. Throughout the study, cryogenic electron microscopy appears as an indispensable means to unravel the morphology of the obtained vesicle−polymer architectures.