Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 3: Focus: Amphiphilic systems III

CPP 3.1: Hauptvortrag

Montag, 23. März 2009, 18:00–18:30, ZEU 222

Formation and exchange kinetics of block copolymer micelles — •Reidar Lund — Donostia International Physics Center/ University of the Basque Country, Paseo Manuel de Lardizabal 4, 20018 San Sebastián

In this presentation, we will review results of both the kinetics associated with unimer exchange in the equilibrium state and the non-equilibrium formation kinetics of block copolymer micelles. For the former, we have shown in a series of experiment using TR-SANS and a novel deuteration scheme, that the unimer exchange of block copolymer micelles is characterized by a very slow logarithmic decay [1]. This opposes the theoretically predicted exponential kinetics proposed by Halperin and Alexander a long time ago. For the latter micellization kinetics, we will show some very recent results [2] using time resolved synchrotron x-ray scattering in combination with stopped-flow where the birth of block copolymer micelles can be directly seen on the millisecond time range. We will further demonstrate that the self-assembly process can be quantitatively described as a special nucleation & growth process where the dominating elemental growth mechanism is stepwise unimeric (single chain) addition without invoking any more complicated higher order mechanism such as fusion/fission.

References [1]R. Lund; L. Willner; J. Stellbrink and D. Richter Phys. Rev. Lett. 96 068302 (2006) [2]R. Lund; L. Willner; M. Monkenbusch; P. Panine; T. Narayanan; J. Colmenero and D. Richter submitted