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Study On Preparation Of Polymerized Fluorescent Microsphere And Fluorescent Gel

Posted on:2010-08-18Degree:DoctorType:Dissertation
Country:ChinaCandidate:C S ZhaoFull Text:PDF
GTID:1101360302466054Subject:Polymer Chemistry and Physics
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Researches and applications of fluorescence material are one of important focus in material field nowadays. Fluorescence materials include organic or inorganic materials. Advantages of organic fluorescence materials are high fluorescence photons efficiency, widely luminescence wavelength and various varieties. Therefore, more attentions are about inorganic materials in investigation and application. Organic fluorescence materials were used as dyes and pigments for many products formerly. For instance, it acted as fluorescent brighteners for some plastic and fibre. And it often was used to dye in fibre as fluorescent dyes, for example nylon. Many new synthetic organic fluorescence materials have excellent photochemical and photophysical characteristic. They are not only used in dyes and pigments, but also are used in biology medication, electron information, engineering materials, environment protect, energy, agriculture and so on. For example, they may be used as DNA cleavers, solar cell, fluorescent probes and OLEDs. Along with studies on synthesize, relations of structure and capability, the excellent photoelectricity would be applied furthest in every fields.Currently, synthesize of organic fluorescence materials are organic fluorescence molecule and fluorescence polymer mostly. Fluorescence emission wavelength and intensity relate to structure of molecule. The molecules often have fluorescence groups and auxochrome. Conjugate degree of molecule and property of substitute group have many influences to fluorescence. Classify of fluorescence materials base on structure of molecule, there are aroma condensed ring compound, intramolecule charge transfer compound with conjugate structure and some metal complex compound. The research of aroma condensed ring compounds are focus on perylene and derivatives. The studies on secondly kind compound are most broad and active. They include stilbene, coumarin derivatives, pyrazolone derivatives, 1,8-naphthalimide derivatives, anthraquinone derivatives and rhodamine derivatives. 8-oxyquinoline was studied most in metal complex compounds. After the relations between structure and fluorescence performance are confirmed, fluorescence molecules are synthesized by appropriate route according to demand of luminescent structure.Polymer fluorescence material is one of important species in function polymer. There are obvious advantages to compare polymer fluorescence material with fluorescence molecule. The consistency of fluorescence molecule and backing is bad. Distributing of fluorescence molecules are not homogeneous, they are easy tofall off and separate from mixture. Fluorescence units are bonded to polymer chain, so they are stable and good at bearing water and organic solvent. The chromophores distributing very homogeneous and the content of chromophore is stable. There are two way to prepare fluorescence polymer. The first, responded active molecules are polymerized by free radical or condensation polymerization. The other way, fluorescence molecules are grafted on polymer chain. Physics mixing is method too. But the way have defect as above. The synthesis is according to structure and reaction condition through suit way.During the last few years, luminescent material has become a focus of investigation. 1,8-naphthalimide derivatives substituted at the 4 position with electron-donating groups can have high fluorescent quantum yields, they have been applied in the many fields. They are used for fluorescent dyes, sensors, organic light emitting diodes (OLEDS), fluorescent probes and photochemical DNA cleavers. With the syntheses of polymerisable 1, 8-naphthalimides, studies and applications of their copolymers are increasing. Copolymers containing fluorescent structure unit have good film forming ability, heat-durability, solvent resistance and high fluorescent quantum yields.In this paper, we used 4-Br-1, 8-naphthalic anhydride as raw material. 4-Br-N-allyl-1, 8-naphthalimide was synthesized by the reaction of 4-Br-1, 8-naphthalic anhydride and allylamine. Then we used 4-Br-N-allyl-1, 8-naphthalimide together with alkyl alcohol to synthesize a series of 4-Alkoxy-N-allyl-1, 8-naphthalimide fluorescence derivatives. IR and 1HNMR were used to analyze the structure of the compound in order to insure that we have obtained the target product. UV-vis spectrum and the fluorescence spectrum were used to study the fluorescence property of the product. The fluorescence properties of monomers were studied, and we also compared the fluorescence properties among monomers in acetone solution or in film-forming process.There are several traditional methods to prepare fluorescent microsphere:emulsion polymerization, dispersion polymerization and suspension polymerization. Emulsifier-free emulsion polymerization can be used to prepare surface clean and mono-disperse microspheres. The pollution of the environment from emulsifier is eliminated. Emulsifier-free emulsion polymerization becomes a focus of research. Especially, it is used in the field of adhesives and paint. In this paper, fluorescent polystyrene microspheres were prepared by emulsifier-free emulsion polymerization. The results showed that emulsifier-free emulsion polymerization was an effective method for the preparation of uniform polystyrene microspheres in micron-size. In order to prepare the polystyrene fluorescent microspheres with controllable sizes, the factors on polystyrene microspheres diameter and size distribution have been investigated and discussed, such as monomer concentration, initiator reagent, the ionic strength of electrolyte. The polymerisable fluorescent monomer, 4-ethoxyl-N-allyl-1, 8-naphthalimide, was synthesized and characterized using FT-IR spectra, 1H-NMR and fluorescence spectra. A copolymer of styrene and 4-ethoxyl-N-allyl-1, 8-naphthalimide was prepared by emulsifier-free emulsion polymerization and characterized using fluorescence spectra.Fluorescent microspheres are a new type of functional polymer materials, widely used in biomedical engineering. At present, the application of the actual production of the fluorescent microspheres, all rely on imports. The study of the preparation of fluorescent microspheres method has important practical significance. Fluorescence refers to the diameter of microspheres in the nano-to micro-scope, load have fluorescent material, by an external stimulus to stimulate the energy of light solid particles. Its shape can be any shape, typical for the spherical shape. Carriers of fluorescent microsphere are organic or inorganic compound materials. In this paper, fluorescent microspheres of polymethyl methacrylate (PMMA) were prepared by emulsion preparation. Emulsifier is copolymer of styrene and maleic anhydride (SMA), which grafted with fluorescent monomer (1, 8 naphthalimide fluorescent units). The temperature was controlled around 78℃, potassium persulfate acted as initiator for emulsion polymerization, reaction time was 12 hours. The degree of hydrolysis of SMA was changed by adding different amount of alkali (NaOH). The best degree of hydrolysis of SMA was studied. Fluorescent nano-microspheres were obtained. The microspheres were confirmed and measured by FT-IR, fluorescence spectra, SEM and hondrometer. The same way was used to prepare polystyrene fluorescent nanospheres. The result shows that PMMA are microspheres and the surfaces of microspheres are not smooth. Particle size is about 100nm. The polymer mic0rosphere can emit an intense fluorescence.
Keywords/Search Tags:fluorescence, 1,8-naphthalimide, copolymer, soap-free emulsion polymerization, fluorescent microsphere, emulsion polymerization, hydrogel
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