University of Connecticut |
Polymer Program Seminar �Self-Assembly of Multicompartment Micelles from ABC Star Copolymers Friday, November 11, 2005 11:00 am , IMS Room 20 Amphiphilic molecules, including lipids, surfactants, and block copolymers, are well-known to self-assemble into micelles in dilute solution. Such aggregates may be spheres, cylinders (“worm-like micelles”), or vesicles (“liposomes” or “polymersomes”). In all cases the amphiphiles divide space into two domains: solvent-philic and solvent-phobic. We are interested in forming multicompartment micelles, in which the solvent-phobic regions are further sub-divided into two or more separate nanodomains. Such structures would represent a step toward more elaborate, hierarchical self-assembled materials, and have possible utility in various storage, transport, and delivery applications. To this end we have prepared a series of model ABC “mikto-arm star” terpolymers, comprising hydrophobic poly(ethyl ethylene), hydrophilic poly(ethylene oxide), and hydrophobic/lipophobic poly(perfluoro propylene oxide) blocks. These polymers self-assemble in dilute aqueous solutions to give a fascinating array of multicompartment micellar structures, that depend systematically on the lengths of the various blocks. The micelles are characterized in detail by cryogenic transmission electron microscopy and dynamic light scattering. The factors that dictate the choice of structure will also be discussed.
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