The Construction Of Amphiphillic Multifunctional Ligand And Thin Film-Controlled Synthesis Of Nanosized Lanthanide Phosphors

On account of the energy match and energy transfer mechanism, relative researches were concentrated on constructing special ligand which possess sensitization, coordination ability and film-forming property, complexing the ligand with rare earth ions to obtain multifunctional lanthanide complexes precursors, and selecting proper condition in order to control the morphology and microstructures of the materials and improve their optical properties.In this paper, by designing special amphiphilic lanthanide complexes as precursors, we put forward a novel optimized synthesis of lanthanide luminescent materials. Firstly, the amphiphilic binary multifunctional lanthanide complexes were constructed by complexing rare earth ions with pre-designed amphiphillic long chain multifunctional ligand. Then, the amphiphilic ternary lanthanide complexes were synthesized by introducing some proper assistant materials into the as-derived binary amphiphilic lanthanide complexes. At last, by selecting the as-derived binary amphiphilic lanthanide complexes and ternary lanthanide complexes with multiple function as the precursors, respectively, both solid luminescent materials and lanthanide complexes LB film have been successfully synthesized. The researches were concentrated on constructing ligand with multiple function and studying the influence of pre-designed multifunctional amphiphilc precursors on the morphology and microstructures of the products. We further explored the feasibility of its application in the field of luminescent materials.Based on the above ideas, we achieved the following results: Firstly, binary amphiphilic multifunctional long chain lanthanide complexes with mono-L cis-butene dicarboxylate (L = hexadecyl, octadecyl and eicosyl), i.e. MAH, MAO and MAE, respectively, were constructed. The corresponding ternary lanthanide (Eu³⁺, Tb³⁺) complexes with the pre-designed monoester ligands and nitrogen heterocyclic ligands (2,2'-bipyridyl (bipy) and 1,10-phenanthroline (phen)) have been successfully synthesized and characterized. The photophysical properties of ternary lanthanide complexes have been studied with ultraviolet spectra, phosphorescence spectra, excitation and emission spectra and luminescent lifetimes. Energy match and energy transfer between the triplet state of ligands and lanthanide ions were examined. It also reveals that the multiply functional ligand are suitable for those of the excited states of the lanthanide ions, especially for luminescent Eu³⁺ ion and Tb³⁺ ion. Secondly, using amphiphilic binary multifunctional long chain lanthanide ions complexes as precursors, we have synthesized three kinds of nanoparticles after calcinating at proper temperatures. They are Y₂O₃:Eu³⁺/Gd_XY_2-XO₃: Eu³⁺, CeO₂ and ZnO materials, respectively. The morphology and microstructures of all the samples were characterized by Scanning electronic microscope (SEM), Transmission electron microscopic (TEM) and X-ray diffraction (XRD), respectively. The photophysical properties of them were studied in detail with IR spectra, ultraviolet absorption spectra, luminescent excitation and emission spectra, respectively. We further studied the influence of amphiphilc precursor molecules on the morphology, microstructures and photophysical properties of our products; Thirdly, it is the first time to prepare ternary lanthanide complexes with long chain MAH/MAO and 1,10-Phenanthroline by using Langmuir-Blodgett (LB) technique. The AFM study showed that he LB film were mainly covered by a large amount of chains like structure probably caused by long chain molecules.