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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 22: Poster Session III - Charged Soft Matter and Theory and Simulation
CPP 22.6: Poster
Wednesday, March 24, 2021, 16:30–18:30, CPPp
ToF-NR investigation of cononsolvency in PNIPAM-based block-copolymer thin films — •Christina Geiger1, Julija Reitenbach1, Lucas P. Kreuzer1, Tobias Widmann1, Peixi Wang1, Robert Cubitt2, Cristiane Henschel3, André Laschewsky3, Christine M. Papadakis4, and Christina Geiger1 — 1TU München, Physik-Department, LS Funktionelle Materialien, 85748 Garching, Germany — 2Institut Laue-Langevin, 38000 Grenoble, France — 3Fraunhofer-Institut für Angewandte Polymerforschung, 14476 Potsdam, Germany — 4TU München, Physik-Department, Physik weicher Materie, 85748 Garching
The diblock copolymer PMMA-b-PNIPAM forms micelles in aqueous solution that exhibit a reversible shell collapse transition at the lower critical solution temperature (LCST). Apart from a temperature stimulus, the collapse can be induced by the addition of organic co-solvents due to the competitive attachment and detachment of water and co-solvent to the PNIPAM chains. We demonstrate that the co-nonsolvency effect is transferrable from solutions to thin film systems. The film swelling and contraction kinetics due to the uptake of water and co-solvent via solvent vapors are investigated with a focus on time-of-flight neutron reflectometry (ToF-NR). Sequential contrasting experiments using protonated and deuterated compounds are performed to differentiate between the distributions of water and co-solvent within the polymer films.