Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 36: Poster: (Hydro)gels and Elastomers

CPP 36.3: Poster

Mittwoch, 13. März 2013, 16:30–18:30, Poster C

Kinetics of aggregation in micellar solutions of thermoresponsive triblock copolymers: influence of concentration, start and target temperature — Joseph Adelsberger¹, Amit Kulkarni¹, Isabelle Grillo², Melissa Sharp³, Achille M. Bivigou-Koumba⁴, André Laschewsky⁴, Peter Müler-Buschbaum¹, and •Christine M. Papadakis¹ — ¹TU München, Physik-Department, Physik weicher Materie, Garching — ²Institut Laue-Langevin, Grenoble, France — ³European Spallation Source, Lund, Sweden — ⁴Uni Potsdam, Institut für Chemie, Potsdam-Golm

Micellar solutions of thermoresponsive block copolymers respond to a small change of temperature across the cloud point with a strong volume change. We have investigated triblock copolymers having a long poly(N-isopropylacrylamide) (PNIPAM) middle block and two short polystyrene (PS) end blocks. Temperature-resolved SANS with contrast matching revealed the collapse of the micellar shell and the subsequent aggregation [1]. Time-resolved SANS during a temperature jump showed that the process involves a number of steps, such as the formation of small imperfect aggregates, their densification and their growth by attachment of single micelles and finally by coagulation [2]. The time constants depend on polymer concentration, start and target temperature [2].
1. J. Adelsberger, C.M. Papadakis et al., Macromolecules 43, 2490 (2010) and Colloid Polym. Sci. 289, 711 (2011).
2. J. Adelsberger, C.M. Papadakis et al., Macromol. Rapid Commun. 33, 254 (2012) and Soft Matter, DOI:10.1039/C2SM27152D