Berlin 2012 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 27: Poster: (Hydrogels) and Elastomers
CPP 27.1: Poster
Wednesday, March 28, 2012, 11:00–13:00, Poster A
Cononsolvency in aqueous solutions of P(S-b-NIPAM) diblock copolymers — •Konstantinos Kyriakos1, Martine Philipp1, Joseph Adelsberger1, Sebastian Jaksch1, Anna Miasnikova2, Andre Laschewsky2, Isabelle Grillo3, Peter Müller-Buschbaum1, and Christine M. Papadakis1 — 1TU München, Physik Department, Physik weicher Materie, Garching — 2Universität Potsdam, Institut für Chemie — 3ILL, Grenoble
Thermoresponsive hydrogels have attracted a lot of attention as switches. PNIPAM exhibits a lower critical solution temperature (LCST) of 32 ∘C. Moreover, PNIPAM exhibits the cononsolvency effect, i.e. a miscibility gap upon addition of a second polar solvent, e.g. methanol. Diblock copolymers consisting of a long thermoresponsive PNIPAM block and a short hydrophobic polystyrene block (P(S-b-NIPAM)), are of great interest regarding their tendency to form core-shell micelles in aqueous solution.
We report here on a stopped-flow experiment with time-resolved SANS on P(S-b-NIPAM) diblock copolymers in micellar solution in D2O to which d-MeOH was added in various mixing ratios. The focus is on the micellar structure and the correlation between the micelles. For all chosen solvent ratios, the growth of clusters with final sizes between 40 nm and 50 nm is observed.