Preparation Of Eu - Superele 3 + - PMMA Fluorescent Materials By Sol - Gel Method And Their Properties

Bonding type rare earth fluorescent polymer materials means, bonded rare earth fluorescent polymer materials that rare earth ions is imported into the polymer during polymerization are highly favored, and it overcomes many issues between rare earth complexes and polymer matrix, such as bad compatibility, poor mechanical properties and transparency, to provide a method for preparing rare earth functional materials of highly fluorescent polymer. Inorganic components of silicon dioxide gel is the important raw materials to prepared organic-inorganic materials because it has many unique advantages, example excellent wear resistance, high rigidity, resistance scratch and cheap, wide variety of source, etc. The Rare Earth fluorescent hybrid materials were prepared by sol-gel polymerization method in this paper, which the silicon dioxide gel made by sodium silicate was used as inorganic components and polymethyl methacrylate(PMMA) served as organic components, meanwhile the rare earth complexes(Eu(MAA)3phen) was added in the system. The main contents are as follows:1. The rare earth ternary complexes (Eu(MAA)3phen) with polymerization activity were synthesized when europium oxide, a-methacrylic acid and1,10-phenanthroline as raw materials. With sodium silicate as the silicon source, the active silianol solution was prepared via acidification, salting and purification in tetrahydrofuran solvent. The rare earth copolymer plank doped with SiO2of transparent fluorescent was prepared by the sol-gel situ polymerization, which methyl mathacrylate as monomer and benzoyl peroxide as initiator, through molding by casting. Meanwhile, the composition and structure of the copolymer were characterized, including thermal stability of the copolymer were tested by TG-STA, the morphology and the distribution of doped SiO2in the copolymer were showed in SEM mages, and the results of optical properties demonstrate characterized emission of Eu3+was existed in copolymer. Otherwise, the fluorescent performances in different content of active silicon and the rare earth complexes were investigated, and the band gap of copolymer was researched.The results showed that the toughness of copolymer was improved because inorganic component active silicon was involved in the copolymerization of methyl methacrylate and rare earth complexes. The heat resistance of hybrid glass was increase10℃, and the glass transition temperature was improved. The band gap transition did not affect with adding active silicon, and the UV absorption peak of copolymer was still located in264nm of rare earth complexes. The best emission peak of copolymer lied at593nm and616nm, according with the characteristic emission of rare earth Eu3+ions. The fluorescent properties of copolymer were excellent with active silicon content at1.5%. At the experimental range, the fluorescent properties of copolymer were aggrandized with the amount of rare earth complexes increasing, and there was on concentration quenching phenomenon.2. In this paper, the monodisperse nano-SiO2microsphere particles were prepared in two ways. Firstly, the classical StOber method was used to preparing monodisperse nano-SiO2microsphere particles; Secondly, with sodium silicate as the silicon source, monodisperse nano-SiO2microsphere particles were obtained by Sol-gel ameliorated under the environment of one-step feeding. The impacts of products prepared by Sol-gel ameliorated in different synthesis process were explored, and investigating the effect of sodium concentration. Otherwise, nano-SiO2microsphere particles were modified with KH-570in order to combine with PMMA to form core-shell materials by the way of chemical bond.The structure of nano-SiO2microsphere particles unmodified and modified was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray spectroscopy. The morphology and particle size of nano-SiO2microsphere particles unmodified and modified were analyzed with scanning electron microscopy(SEM)、transmission electron microscopy(TEM) and laser light scattering particles size analyzer(DLS). The hydrophobic properties of nano-SiO2microsphere particles unmodified and modified were tested via the contact angle method.The study discovered nano-SiO2microsphere particles can be acquired by Sol-gel ameliorated under mild conditions, which simplified the preparation method and process of the SiO2microsphere. The surface carbon content and hydrophobic performance of SiO2microsphere was increased with the increasing of KH-570modifying time. With the aggrandizing of the molar ratio between SiO2and KH-570, the surface carbon content of SiO2microsphere was raise, but the hydrophobic performance was superior up to37.8°, when the molar ratio was1:4.3. The PMMA-Eu(MAA)3phen@SiO2core-shell fluorescent microspheres were prepared using dispersion polymerization method, which the SiO2microsphere modified with KH-570%rare earth complexes(Eu(MAA)3phen) and MMA dispersed in the system of polyvinyl pyrrolidone(PVP-K30) as dispersing agent to graft polymerization, with AIBN as initiator. Meanwhile, the chemical and optical properties of PMMA-Eu(MAA)3phen@SiO2core-shell fluorescent microspheres were characterized, and the effects of polymerization condition on the properties of composite particles and bandgap were explored.The discusses found that the core-shell structure of composite materials prepared by dispersion polymerization was demonstrated in the results of TEM. The thermal decomposition temperature of inorganic-polymer composite microspheres has augment38℃than it of pure PMMA materials. The best emission peak of core-shell materials located at593nm and616nm, which expressed the characteristic emission peak of rare earth Eu3+ions. The fluorescent properties were optimum when the content of rare earth complexes up to0.7g, and concentration quenching phenomenon occurred once concentration exceeded it. The bandgap of PMMA-Eu(MAA)3phen@SiO2core-shell fluorescent microspheres was5.11and it tends width.