Study On Synthesis And Properties Of Rare Earth/ Polyurethane Nanoarrays Luminescent Materials

Rare earth elements exhibitied many excellent properties in light, electricity, magnetic and heat for their particular 4f electronic structure, especially rare earth elements have some spectroscopy properties the general elements have never dreamed of, rare earth luminescence materials attracted more and more attention for their extensive application in new optical materials. The reactive functional groups can be introduced in the coordination complexes by the coordination of rare earth ions and organic small molecules ligand, so the rare earth compleses can be served as a good luminescence component introduced to polymer nanoarray. On this basis, a new type of one-dimensional polymer luminescent material can be synthesized and will have more wider application prospects.In this thesis two kinds of europium and terbium complexes with the activity double bond(C=C) were synthesized using a simple solution method. The bonded rare raeth/polyurethane nanoarrays luminescent material were prepared by the in situ polymerization of poly(urethane-methacrylate)s and rare earth complex in the confined space of AAO template. Their structure and properties were characterizated by infrared spectrum, thermal analysis, fluorescence spectroscopy, FESEM, TEM and other test methods, the growth process of namoarrays in the confined space was studied, and their luminous effect of rare earth ions in the polyurethane matrix were discussed.Main contents and results of this paper are as follows:1. Two kinds of crotonic acid europium and 4-pentenoic acid terbium complexes with a activity double bond(C=C) were synthesized using the solution method. The single crystal were cultivated by evaporation method at room temperature, their structure and properties were characterized by XRD, FTIR, 1H-NMR, TG and fluorescence spectrum. The molecular structure of two complexs were obtained by crystallographic structural analysis.The ultraviolet absorption spectra showed that the two ligand had strong absorption in the uv region, and showed Ï€â†' Ï€* transition mainly; The TG results indicated that two kinds of complexes had good thermal stability; The fluorescence spectrum showed that crotonic acideuropium complexs exhibited the characteristic emission of corresponding europium ions under the 395 nm excitation wavelength, and the fluorescence lifetime was 0.41718 ms;green glow 4-pentenoic acid terbium complexs had the characteristic emission of corresponding terbium ions under 354 nm excitation wavelength, and the fluorescence lifetime was 2.07126 ms. This established the foundation for the next preparation of bonded luminous material.2. One-dimensional bonded rare earth/polyurethane nanoarrays luminescent materials were prepared by the homemade rare earth complexes crosslinked with polyurethane in the pore of AAO template with AIBN as initiator. We used the negative pressure method, the surface modification of AAO templates and solution-dilution method to study the microstructure of nanoarrays. FESEM and TEM morphology characterization showed that the rare earth/polyurethane nanoarrays had smooth outer wall, neat and uniform diameter,and rare earth complexes dispersed homogeneously in polyurethane system, so the diameter of the nanoarrays can be controlled by the aperture of the AAO template. Infrared spectrum,EDS and XPS spectrum showed that the rare earth complexes successfully bonded in the chain of polyurethane molecula. TG thermal analysis showed that the thermal decomposition temperature of the rare earth/polyurethane nanoarrays reached 221.25 °C,and decreased 17 °C compared with pure polyurethane nanoarrays. Fluorescence spectra showed that the rare earth/polyurethane nanoarray had the characteristic fluorescence of rare earth ions, and with the increase of rare earth ion concentration the fluorescence intensity increased synchronously. Fluorescence decay curve showed that the fluorescent lifetime of crotonic acid europium/polyurethane nanoarrays increased with the increase of crotonic acid europium, while the fluorescent lifetime of 4-pentenoic acid terbium/polyurethane nanoarrays changed a little with 4-pentenoic acid terbium content increased.3. Combined FESEM and controlling the different infiltration time for 1 hour, 3 hour and 12 hour respectively, initialy explored the growth process of the rare earth/polyurethane nanoarrays in the nanopore of AAO template. As the AAO template possessed high surface energy, prepolymer can infiltrate the channel rapidly in the initial time, with time growing,polymer fully populated the channel, then the rare earth/polyurethane nanowires were obtained as a result of polyurethane intermolecular forces greater than the adhesion strengthof the polyurethane.