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CPP: Chemische Physik und Polymerphysik

CPP 5: SYMPOSIUM: Dynamics of multi-component fluids POSTER

CPP 5.22: Poster

Freitag, 4. März 2005, 17:15–19:00, Poster TU D

Structural changes in diblock-copolymer micelles induced by comicellization with surfactants — •Thomas Hellweg¹, Anette Nordskog¹, and Helmut Schlaad² — ¹TU Berlin, Stranski-Laboratorium, Strasse des 17.Juni 112, 10623 Berlin — ²MPI-KGF, Potsdam-Golm, 14424 Potsdam

Because of the incompatibility of the two blocks of amphiphilic block-copolymers, they form micellar aggregates in selective solvents. In the present work we investigate the influence of ionic surfactants on the structure of nonionic diblock-copolymer micelles applying the concept of changing the natural curvature of amphiphilic interfaces, which allows to tune the micellar shape. The diblock-copolymer polybutadien-b-poly(ethyleneoxide) PB-PEO with a ratio of the block sizes N_PB/N_PEO ≥ 3/4 forms wormlike micelles in aqueous solutions [1]. Upon addition of short-chain ionic surfactants mixed block-copolymer/surfactant micelles are formed. Because of the repulsive interactions of the ionic headgroups the effective headgroup area increases, which leads to a higher curvature of the amphiphilic interface and a change of the overall micellar structure. Using mainly static and dynamic scattering techniques the influence of different surfactants on these block-copolymer micelles is investigated [1, 2].

[1]A. Nordskog, H. Egger, G. H. Findenegg, Th. Hellweg, H. Schlaad, H. von Berlepsch, and C. Böttcher: Phys. Rev E, 68 (2003) 11406/1-14. [2]A. Nordskog, T. Fütterer, H. Schlaad, A. Heinemann, H. von Berlepsch, C. Böttcher, and Th. Hellweg: PCCP, 6 (2004) 3123-3129.