MOLECULAR-ORGANIZATION IN MIXED MONOMOLECULAR FILMS AND LANGMUIR-BLODGETT LAYERS OF ALKYLAMINOSTYRYL-PYRIDINIUM DYES AND STEARIC-ACID

The molecular organization of mixed monolayers containing aminostyryl- pyridinium dyes of different alkyl chain lengths and stearic acid was studied at the air-water interface and on solid substrates. The surfac e pressure-area and surface potential-area isotherms indicate that the molecular organization in these mixed films is controlled by the alky l chains. Polarized angular reflection measurements at the air-water i nterface provide evidence for the presence of two dye populations with different orientations. Mixed monolayers on hydrophobized glass subst rates transferred via vertical dipping show analogous results. In the case of the short-chain dye, H aggregation is observed together with m onomer chromophores with different orientations. Furthermore, non-idea l mixing of dye and matrix is found in this case.