Novel layer-by-layer complexation technique and properties of the fabricated films

A novel layer-by-layer complex-fabrication technique for multilayer film as sembly was developed by alternatively dipping desired substrates in macromo lecular ligands and Eu3+ ion solutions, A water-soluble, luminescent thioph ene-based polymer, viz., poly[2,5-(3-carboxymethyl urethanyl ethyl) thiophe ne] (H-PURET), was prepared and used as the macromolecular ligand. Multilay er deposition was monitored using UV-visible spectroscopy by following the absorbance increase due to the deposition of the polymer layer. Multilayer thin films were characterized using infrared and fluorescence spectroscopic techniques, transmission electron microscopy (TEM), and energy-dispersive X-ray spectrometry (EDXS). The conductivity and the electroluminescence pro perties of the conjugated polymer-Eu3+ complex multilayer films were also m easured. The observed electroluminescence intensity of conjugated polymer-m etal complex multilayer film was about 2 times higher than for the conjugat ed polymer by itself. The approach is general in that other macroligands an d metal ions may be employed.