Regensburg 2016 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 12: Poster: Colloids and Complex Fluids
CPP 12.1: Poster
Montag, 7. März 2016, 18:15–21:00, Poster B2
Aggregation behavior of doubly thermo-responsive polysulfobetaine-b-poly(N-isopropylmethacrylamide) diblock copolymers — •Natalya Vishnevetskaya1, Viet Hildebrand2, André Laschewsky2, Peter Müller-Buschbaum1, and Christine M. Papadakis1 — 1TU München, Physikdepartment, Physik weicher Materie — 2University of Potsdam, Institute of Chemistry
Diblock copolymers consisting of a non-ionic poly(N-isopropylmethacrylamide) (PNIPMAM) block and a zwitterionic poly(sulfobetaine) (PSPP block) feature both a lower and an upper critical solution temperature (LCST and UCST) in aqueous solution. PSPP-b-PNIPMAM is expected to form (i) micelles with a PNIPMAM shell and a PSPP core or vice versa at low and high temperatures and (ii) unimers or large aggregates in the intermediate temperature range, depending on temperature, chemical structure and block length, as well as on the presence of electrolyte. The phase transition temperatures in dependence on the electrolyte concentration are investigated by turbidimetry. The aggregation behavior which is responsive to two stimuli (temperature and electrolyte concentration), and depends on the architecture of the non-ionic block, is studied by temperature-resolved small-angle neutron scattering (SANS) and dynamic light scattering (DLS). In D2O PSPP-b-PNIPMAM forms indeed micelles above the LCST and below the UCST. The micelle structures depend significantly on the block lengths, whereas the salt-induced changes are only minor.