Dresden 2006 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 5: Polyelectrolytes

CPP 5.7: Vortrag

Montag, 27. März 2006, 16:15–16:30, ZEU 160

Micelle formation of amphiphilic poly(2-alkyl-2-oxazoline) block copolymers — •C.M. Papadakis¹, T. Bonné¹, R. Ivanova¹, P. Štěpánek², K. Lüdtke³, and R. Jordan³ — ¹Physikdepartment E13, Technische Universität München, James-Franck-Str. 1, D-85747 Garching — ²Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague — ³Lehrstuhl für Makromolekulare Stoffe, Chemiedepartment, Technische Universität München, 85 747 Garching

Amphiphilic copolymers find numerous applications, e.g. for drug delivery or as nanoreactors. Poly(2-oxazoline) block copolymers constitute a very versatile system: The amphiphilicity can be controlled by the choice of side groups, and in aqueous solution, unimers, micelles or micellar hydrogels are formed, depending on the block copolymer architecture.

Fluorescence correlation spectroscopy (FCS) experiments on aqueous solutions of poly[(2-nonyl-2-oxazoline)_n-b-(2-methyl-2-oxazoline)_m], P[(MOx)_m(NOx)_n], diblock copolymers with a small fraction of identical, fluorescence-labeled polymers as tracers allowed us to study the micelle formation at very low concentrations [1]. In contrast, low molar mass fluorescence tracers lead to an overestimation of the micellar diffusion coefficients, because of the exchange dynamics of the tracer. Micelles formed by P[(MOx)_m(NOx)_n(MOx)_m] triblock copolymers are smaller than the ones from the corresponding diblock copolymers, as expected from the additional constraints for the hydrophobic blocks.

[1] T.B. Bonné, K. Lüdtke, R. Jordan, P. Štěpánek, C.M. Papadakis, Coll. Polym. Sci. 282, 833 (2004)