Self-assembly of polystyrene-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) triblock copolymer in aqueous media: Comparison and critical evaluation of results of long-term multidisciplinary studies

POLY 71

Karel Prochazka, prochaz@vivien.natur.cuni.cz1, Miroslav Stepanek1, Jana Humpolickova1, Pavel Matejicek1, Martin Hof2, and Milena Spirkova3. (1) Department of Physical and Macromolecular Chemistry, Charles University in Prague, Faculty of Science, Albertov 6, 128 43 Prague 2, Prague, Czech Republic, (2) Biophysical Chemistry, Jaroslav Heyrovsky Institute of Physical Chemistry, Dolejskova 3, 182 23 Prague 8, Czech Republic, (3) Polymer Networks and Mechanical Properties of Polymers, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky square 6, Prague 6 - Petriny, Prague, Czech Republic
We present critical evaluation of results of multidisciplinary studies (LS, fluorescence, AFM) on polystyrene-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) micelles in aqueous media. The micelles with very low association numbers (ca. 10) can be prepared in acidic buffers by a combination of dialysis and quenching. Since the PS cores are small, the glass transition temperature decreases and PS chains may reorganize even though the unimer exchange between micelles is kinetically frozen. The micelles undergo reversible micellar agregation with pH in acidic solutions. They aggregate irreversibly when transfered in basic media. The solvent relaxation study reveals that the aggregation of micelles is due to increasing mobility of water molecules at low pH resulting in a hindered solvation of PEO units.
 

Multicompartment Micelles: Higher Order Self-assembly of Block Copolymers
1:30 PM-5:00 PM, Sunday, 10 September 2006 San Francisco Marriott -- Salon B2, Oral

Division of Polymer Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006