Study On Nano - Structure And High Molecular - Based Luminescent Materials Containing Organic - Rare Earth

Composites containing optically active lanthanide ions used as phosphors and laser materials because of their sharp and intense emissions based on f-f electronic transitions. Pure complexes do not have good thermal stabilities, which limited practical uses. New strategies were innovated to dissolve these problems. For example, lanthanide complexes can be incorporated into organic, inorganic, or organic/inorganic hybrid matrixes.On the base of analyzing the excited energy level of lanthanide trivalent ions and triplet state of ligands, the research work focus on finding the appropriate organic ligands for lanthanide ions, preparing silica nanoparticles carried crystallized organic complexes via Sol-gel method, we choose silica as the matrix based on the fact that the particle size can be controlled according to stober method, at the meanwhile, the research devote on doping the nano powder into polymer spinning solution, achieved the electrospinning fibers which can emit red or green luminescence under UV light, the polymer matrix include PMMA、PAN、PVP, etc. The SiO2:Eu(tta)3phen nano powder modified by silane coupling agent was blended with granular polypropylene by means of micro-twin-screw blender in order to prepare the polypropylene hybrid material.Successful preparation of nanoparticles with high luminescent properties is the precondition of this research. Choosing appropriate organic ligands for the corresponding rare earth, than preparing crystallized lanthanide rare earth complex embedded in silica matrix, the particle size can be controlled through changing the experimental conditions. The results indicated that the crystallized organic complex embedded onto or into the nano silica nanoparticles by high resolution transparent electronic microscope, this is a fire-new discovery. FT-IR spectra, high resolution luminescence spectroscopy, X-ray photoelectron spectroscopy measurements were used to characterization, at the same time, the thermostability of the nanoparticles was improved markedly compared with the pure complex.This research contribution prepared high luminescent fibers via electrospinning technique, and TEM results indicated that the nanoparticles have good dispersibility with smaller particle size in the polymer matrix compared with the original one. EDS results combined with luminescent properties showed that the nano particles were successfully embedded in the polymer matrix, and luminescent spectroscopy showed that the hybrid fibers emit the characteristic spectra of the corresponding lanthanide ions. Large amount of experiments made to compare that different parameters affect the morphology of the fibers, such as voltage, solvent, concentration of the nanoparticles.Luminescent polymer hybrid materials prepared by melt blending method showed that nanoparticles are dispersed well in polymer matrix, the luminescent, mechanical properties are improved because of the good dispersity. The increased crystallization temperature of polypropylene is attributed to heterogeneous nucleation of nanoparticles for polymer crystallization through DSC characterization.Above all, this research contribution focus on preparing a kind of luminescent nanoparticles which are nano-silica carried crystallized lanthanide complexes. Electrospinning fibers doped with the nanopaticles show high luminescent properties. The increased crystallization temperature of polypropylene is attributed to heterogeneous nucleation of nanoparticles for crystallization. In summary, we believe that this research contribution provides a novel preparation technique to get luminescent hybrid materials and will have important potential applications for new luminescent materials and functional devices in wide areas.