Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 38: Poster: Colloids and Complex Liquids

CPP 38.14: Poster

Mittwoch, 16. März 2011, 17:00–19:00, P2

Supramolecular structure changes of tubular J-aggregates on various substrates upon drying from water — •Chien-Lie Lee, Dörthe M. Eisele, Stefan Kirstein, and Jürgen P. Rabe — Humboldt-Universität zu Berlin, Germany

Tubular J-aggregates self-assemble from amphiphilic cyanine dyes in aqueous solution. Although the main driving force for the self assembly results from the hydrophobic effect there are other contributions to the cohesion of the molecules. Therefore, it is possible to transfer these aggregates onto solid substrates where they remain intact, without substantial changes of the morphological and supramolecular structure, as long as as the samples are not completely dried [1].

Here we investigate the role of the hydrophilicity or hydrophobicity of the substrate on the drying and hence destruction of the aggregate structure. The high sensitivity of the optical spectra to changes of the molecular packing within the J-aggregates is used to probe the structure. The hydrophilicity of the substrate is controlled by coating with polyelectrolyte or polymer layers and the drying of the aggregates is recorded time dependent and under controlled humidity.

[1] D.M. Eisele, J. Knoester, S. Kirstein, J.P. Rabe and D.A. Vanden Bout, Nature Nanotech. 4 (2009) 658;