Mesoscopic organization of two-dimensional J-aggregates of thiacyanine in Langmuir-Schaefer films.
When dioctadecyl dimethylammonium bromide (DODAB) is compressed on a subphase containing 3,3'-disulfopropyl-5,5'-dichlorothiacyanine (THIAMS), adsorption of the dye to the DODAB monolayer results in the formation of J-aggregates which spontaneously organize into polygonal domains of micron size. The features of the domains depend on the surface pressure. The fluorescence of the individual domains is polarized. The shapes of the domains determined by fluorescence microscopy and atomic force microscopy (AFM) are identical. The domains differ however significantly from those observed after injection of a 3,3'-disulfopropyl-5,5'-dichloro-9-ethylthiacarbocyanine (THIATS) or THIAMS solution below a precompressed DODAB film, as well as from the domains observed upon compression of a DODAB monolayer on a subphase containing 10(-6) M THIATS.
Tian
Chun-Hong
CH
Laboratory for Photochemistry and Spectroscopy, Department of Chemistry, Katholieke University Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium.
Liu
Dao-Jun
DJ
Gronheid
Roel
R
Van der Auweraer
Mark
M
De Schryver
Frans C
FC