Morphology Control Of Europium β-diketone Complex

Luminescent nanotubes prepared by layer-by-layer (LbL) self-assembly based on electrostatic interaction between oppositely charged polyelectrolytes molecules, have potential applications in luminescent materials and cell imaging. We first prepared monodisperse polyelectrolyte nanotubes by the LbL technique. Micropores of polycarbonate (PC) and anodic aluminum oxide (AAO) membranes were used as the templates, respectively. Poly-sodium 4-styrenesulfonate (PSS) and poly-dimethyl diallyl ammonium chloride (PDDA) or poly-allylamine hydrochloride (PAH) alternately adsorbed onto the inner walls of templates. Then synthesis of rare earth complex in confined space of successive inner walls. Assembly of luminescent nanotubes or nanorods containing rare earth complex was confirmed by scanning electronic microscope (SEM), fluorescence microscope (FM) and fluorescence spectrophotometer (FS).Dispersion of polyelectrolyte nanotubes was obtained firstly. To aid release and dispersion of individual nanotubes upon template dissolution, polyelectrolyte layers on the surface of template were removed by oxygen plasma treatment combined with wet polishing. Influences of preparation methods, solvents and dissolution time were studied to optimize experimental conditions in order to achieve large number of monodisperse polyelectrolyte nanotubes are prepared.In the confined space of AAO@(PSS/PAH)8.5, Eu(TTA)3Phen nanorods with intense fluorescence were in-situ synthesized. Eu(TTA)3Phen infiltrates nearly full of the inner pores of the confined space. The reason might be that between Eu3+ and PSS there are many binding sites, which serve as nucleation sites facilitating the growth and binding of more Eu(TTA)3Phen.The morphology and fluorescence of Eu(TTA)3Phen in cetyltrimethylammonium bromide (CTAB) solutions with different concentrations (less than critical micelle concentration (CMC), equal to CMC and more than CMC) were studied. The increased solubility of Eu(TTA)3Phen in CTAB micelles was utilized to enrich Eu(TTA)3Phen and protect its fluorescence against energy loss between Eu(TTA)3Phen and water molecules. Luminescent nanotubes containing rare earth complexes will benefit many fields including luminescent materials and fluorescence immunoassay.