Autor: |
Tian, C.-H., Zoriniants, G., Gronheid, R., Auweraer, M. Van der, Schryver, F. C. De |
Zdroj: |
Langmuir; November 2003, Vol. 19 Issue: 23 p9831-9840, 10p |
Abstrakt: |
The influence of surface pressure and adsorption time on the size and shape of J aggregates of 3,3-disulfopropyl-5,5-dichlorothiacyanine sodium salt (THIAMS) adsorbed onto dioctadecylammonium bromide (DODAB) monolayer were investigated. After deposition of the monolayers on a hydrophobic glass substrate by the Langmuir−Schaefer (LS) technique, confocal fluorescence microscopy and atomic force microscopy (AFM) were used to study their fluorescence and topography. The difference in size and shape of the J aggregates formed at different surface pressure and adsorption times may be caused by a different rigidity and charge density of the DODAB film. The total thickness of the films amounts to 4.5 ± 0.2 nm which confirms that THIAMS forms 2D aggregates with edge-on orientation when adsorbed to a DODAB monolayer. In the bulk of the J aggregate the fluorescence was polarized in all films investigated. THIAMS molecules adsorbed to the dark areas between the fluorescence domains remained mainly as monomers and dimers. |
Databáze: |
Supplemental Index |
Externí odkaz: |
|