Berlin 2018 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 69: Focus: Polymers in Multi-Component and Aqueous Solutions I - organized by Jens-Uwe Sommer and Debashish Mukherji
CPP 69.4: Vortrag
Donnerstag, 15. März 2018, 16:00–16:15, C 130
Orthogonally and doubly switchable diblock copolymers: Schizophrenic behavior — Natalya S. Vishnevetskaya1, Viet Hildebrand2, Bart-Jan Niebuur1, Peter Müller-Buschbaum1, André Laschewsky2,3, and •Christine M. Papadakis1 — 1TU München, Physik-Department, Garching, Germany — 2Universität Potsdam, Institut für Chemie, Germany — 3Fraunhofer-Institut für Angewandte Polymerforschung, Potsdam-Golm, Germany
Doubly switchable diblock copolymers from blocks featuring lower and upper critical solution temperature behavior (LCST, UCST) may serve for advanced delivery purposes. We present results from diblock copolymers having a thermoresponsive LCST block and a zwitterionic UCST polysulfobetaine block, which is sensitive to ionic strength as well [1]. In aqueous solution, these diblock copolymers are expected to form core-shell micelles with the UCST block in the core and the LCST block in the shell or vice versa, i.e. so-called schizophrenic behavior. Depending on the values of the respective cloud points, the switching between these states may proceed via a molecularly dissolved state or via precipitation.
Using turbidimetry and small-angle neutron scattering, we investigate the phase behavior and the micellar structures in dependence on the choice of the two blocks and the block copolymer composition. Orthogonal and double switching behavior is identified and is found to depend crucially on these factors [1].
1. N. S. Vishnevetskaya et al., Macromolecules 49, 6655 (2016) and 50, 3985 (2017).