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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 88: Responsive and Adaptive Systems
CPP 88.7: Vortrag
Donnerstag, 19. März 2020, 11:00–11:15, ZEU 114
Thermal behavior and co-nonsolvency of the amphiphilic diblock copolymers PMMA-b-PNIPAM in aqueous solution — •Chia-Hsin Ko1, Cristiane Henschel2, Geethu P. Meledam1, Martin Schroer3, Peter Müller-Buschbaum1, André Laschewsky2,4, and Christine M. Papadakis1 — 1Physics Department, Technical University of Munich, Garching, Germany — 2Institut für Chemie, University of Potsdam, Potsdam-Golm, Germany — 3European Molecular Biology Laboratory, Hamburg, Germany — 4Fraunhofer Institute for Applied Polymer Research IAP, Potsdam-Golm, Germany
Amphiphilic diblock copolymers having a hydrophobic poly(methyl methacrylate) (PMMA) block and a thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) block form core-shell micelles in aqueous solution. The PNIPAM blocks are not only sensitive to temperature, but also to the solvent composition. Adding methanol as a cosolvent causes these blocks to collapse which reduces the transition temperature, i.e. co-nonsolvency is observed. We focus on investigating (i) the structure of the self-assembled micelles and the changes upon collapse and aggregation with increasing temperature, and (ii) the co-nonsolvency effect of PMMA-b-PNIPAM in pure D2O and in different D2O/CD3OD mixtures using turbidimetry, differential scanning calorimetry (DSC), dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). The results reveal the role of the nature of the thermoresponsive block on the thermal behavior and the morphology changes upon temperature and solvent composition.