Preparation And Performance Of Rare Earth Based Polystyrene Microspheres

Rare earth-based polystyrene fluorescent microspheres combined the merits of rare earth elements and polystyrene microspheres.Specifically,rare earth elements delivered long fluorescence life and superior fluorescence intensity.But external environment may hinder their performance.Meanwhile,polystyrene microspheres exhibited good stability and the surface of polystyrene microspheres are easy to be functionalized,which can protect rare earth elements from external environment.Rare earth-based polystyrene fluorescent microspheres showed a profound application in biological medical,inspection imaging,drug screening and gene analysis due to its excellent fluorescence performance.Recently,tremendous efforts have been foucused on the promotion of the fluorescence intensity of fluorescent microspheres and fluorescent life to broad the application fields of fluorescent microspheres and exert its unique advantage.In this paper,eight kinds of rare earth europium complexes were successfully prepared,aiming to obtain the europium complexe with superior fluorescence performance.Based on the improvement of the preparation stratagies of polystyrene microspheres,uniform rare earth-based polystyrene fluorescent microspheres with good dispersity were prepared.This thesis provided the experimental reference for the study of rare earth-based fluorescent microspheres.The main work of this paper can be divided into following parts:1.The o-phenanthroline was modified as the second ligand and a copolymerable carbon-carbon double bond was introduced to prepare 5-acrylamido-1,10-o-phenanthroline（Aphen）.Then,four kinds ofβ-diketones were selected as the first ligand to prepare rare earth europium compounds.The structure of four europium complexes were characterized and analyzed by FT-IR,UV and fluorescence spectra measurements.The results showed that the four rare earth europium compounds with Aphen as the first ligand were successfully prepared and delivered superior luminescence purity and fluorescence intensity.The fluorescence spectra showed that the fluorescence intensity of Eu（β-NTA）₃（Aphen）which was prepared with the first ligandβ-NTA as monomer was stronger under the same test conditions.2.Triphenylphosphine oxide was served as the second ligand and four kinds ofβ-diketones were selected as the first ligand to prepare rare earth europium compounds.The structure of four europium complexes were characterized and analyzed by FT-IR,UV,TGA analysis and fluorescence spectra.The results demonstrated that four rare earth europium complexes with TPPO as the first ligand were successfully synthesised.The fluorescence spectra exhibited that the fluorescence intensity of Eu（BFA）₃（TPPO）₂ prepared with the first ligand BFA as monomer was stronger than that of the rare earth complex with Aphen as the second ligand at the same concentration.3.Based on the improved preparation stratage of polystyrene microspheres,two rare earth europium complexes（Eu（β-NTA）₃（Aphen）and Eu（BFA）₃（TPPO）₂）which showed high fluorescence intensity were selected as the luminescence center to prepare rare earth fluorescent microspheres.Eu（β-NTA）₃（Aphen）was copolymerized with styrene to prepare fluorescent microspheres.Eu（BFA）₃（TPPO）₂ fluorescence microspheres were prepared by in-situ dispersion polymerization.The structure of fluorescence microspheres were characterized and analyzed by FT-IR,TGA analysis,SEM,fluorescence spectroscopy.The results showed that the fluorescence microspheres can be successfully prepared with good dispersion and narrow distribution by this method.Meanwhile,Eu（β-NTA）₃Aphen was copolymerized in fluorescent microspheres and Eu（BFA）₃（TPPO）₂ was embedded in polystyrene microspheres during in-situ dispersion polymerization.The fluorescence spectra results indicated that the fluorescence intensity can be tuned by changing the content of Eu complex in rare earth fluorescent microspheres.The optimal doping amount of Eu（BFA）₃（TPPO）₂ in styrene is 40 mg due to the restriction of saturation solubility.