LANGMUIR-BLODGETT-FILMS OF FLUORESCEIN DERIVATIVE CONTAINING 2 LONG ALKYL CHAINS

Fluorescein derivative containing two long alkyl chains was synthesized. The compound gave stable monolayer on the air-water interface. Fluorescence microscopy and transmission electron microscopy showed that the monolayer was homogeneous and highly ordered. Multilayers were also built up on different substrates which are in the periodic structure. The thickness per layer measured by X-ray diffraction and transmission electron microscopy is about 2.1-2.5 nm. The plane of chromophore lies in parallel to the substrate surface. There are strong intra- and inter-layer interactions between the molecules in the same layer and between layers. Molecular aggregation may occur depending on the fabrication conditions, such as surface pressure, number of layers and interfacial energy.