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Preparation And Characterization Of Hybrid Nanoparticles By Miniemulsion Polymerization And Atom Transfer Radical Polymerization

Posted on:2010-06-03Degree:DoctorType:Dissertation
Country:ChinaCandidate:J J ZhangFull Text:PDF
GTID:1101360272496196Subject:Polymer Chemistry and Physics
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Hybrid nanoparticles are a hotspot in materials science. Combining the properties of organic and inorganic components, this kind of hybrid materials has excellent and special capability as compared to its components. The hybrid materials can show synergistic effects of its components effectively by adjusting the proportion of its components, for example, the thermal stability, mechanical intensity and optical properties of polymer can be improved by adding of the inorganic components and the elasticity and film-formation-ability of the inorganic materials can be improved by adding of the organic components, thus the novel hybrid materials with the whole properties of its organic and inorganic components can be obtained. The inorganic or organic/polymer core-shell hybrid materials have novel capability which was endowed by the multifarious shell, so such materials have been widely used in chemistry-surface- modify, catalysis, optics and magnetics.Miniemulsion polymerization is a novel polymerization method, the size and component of the oil drops don't change during the course of polymerization, the oil drops can be seen as minireactors and such sub-microdrops become the site of inducement and nucleation by using co-surfactant and miniemulsion. Owing to atom transfer radical polymerization (ATRP) is very compatible with most of functional group, thus it is a kind of important method to synthesize novel functional material of polymer. ATRP possesses monomer function, initiator function and terminal group function of polymer. Besides, synthesized polymer contains narrow distribution of molecule weight and line-structure by ATRP, which can extend the field of application of polymer. Therefore, ATRP has had great popularity in synthesized field of polymer as a novel method.ZnO is not only an important semiconductor nano-material but also serves widely as catalyst for chemical reactions, photocatalysts, photoelectric conversion, and photoluminescent materials. Compare with cadium (Cd) compound nano-material, such as CdTe, CdSe and CdS, ZnO possesses advantages, such as nontoxicity, easy synthesis and so on. Poly(p-phenylene vinylene) (PPV) and its derivatives have attracted a great deal of attention in recent years because of their interesting electroluminescent (EL) properties and potential applications as the active emitting layer in light-emitting diodes. Polymeric EL materials offer a number of advantages over inorganic EL materials, such as low operating voltages, full-color displays, fast response time, high luminescent efficiency, high-quality displays and easy device processability with semiconductor technologies. In recent years, these polymers have also been developed for use in photovoltaic diodes, light-emitting electrochemical cells, photodetectors and image sensors. Superparamagnetic nanoparticles of Fe3O4 have attracted much attention for therapeutic and diagnostic applications, such as magnetic resonance imaging (MRI) contrast agent, tissue repair, immunoassay, targetable drug/gene/protein carries, and cell separation. As one kind of catalyzer enzyme has a number of advantages such as highly efficient, exact selectivity of substrate. In recent years, with the development of the biomedicine a number of enzyme which possesses biotherapy were discovered and extensive investigated.We have demonstrated that MPS-modified ZnO colloid particles with different surface properties can be gained by adjusting the amount of added MPS and ZnO-coated PS and PS-encapsulated ZnO hybrid nanoparticles can also be prepared with miniemulsion polymerization. The prepared two types of hybrid nanoparticles with different core–shell structures not only retain their photoluminescent properties, but also display the flexibility and easy processing of polymer, which give promise to potential applications in the fields of optical materials, photoconducting devices, and so on. The prepared two types of hybrid nanoparticles with different core–shell structures not only retain their photoluminescent properties, but also display the flexibility and easy processing of polymer, which give promise to potential applications in the fields of optical materials, photoconducting devices, and so on. We synthesized PS/MEH-PPV fluorescence hybrid nanoparticles by miniemulsion polymerization. A series of fluorescence microspheres with different emitting wavelength was obtained by controlling quality of initiator azobisisobutyronitrile (AIBN) to adjust emitting wavelength of microspheres. In further, acrylic acid monomer was added into polymerization system, after polymerization fluorescence hybrid nanoparticles with carboxyl group on the surface of nanoparticles was obtained, and these fluorescence hybrid nanoparticles give promise to potential applications in the fields of optical materials and biology.Fe3O4-PDMAEMA, BSA-PDMAEMA and BP-RNase A-PDMAEMA hybrid nanoparticles was prepared with atom transfer radical polymerization. In order to increase surface positive charge of hybrid nanopartiles and dispersibility in aqueous solution, Fe3O4-PDMAEMA nanoparticles was quaternized by CH3I. Fe3O4-PDMAEMA-q hybrid nanoparticles containing positive charge have a ability to attach protein via electrostatic effect, and efficiently deliver protein into Hela cells with magnetic field. Our research results depict these Fe3O4-PDMAEMA hybrid nanoparticles are as efficient protein carrier to apply in the field of industrial catalysis and biomedicine. By controlling initiator amount and polymerization time BSA-PDMAEMA and BP-RNase A-PDMAEMA hybrid nanoparticles of various size was gained. Positive charge PDMAEMA endowed BSA and BP-RNase A with a ability that can efficiently penetrate cellular membrane into cells. Line-structure PDMAEMA also endowed BP-RNase A with excellent substrate permeability of macromolecule substrate and a new function to effectively reduce interaction of BP-RNase A with inhibitor to contribute to their cytotoxicity for Hela cells. BP-RNase A-PDMAEMA hybrid nanoparticles show cytotoxicity can make it as a anticancer drug to apply in biomedicine field.In summary, we prepared ZnO/PS, MEH-PPV/PS, Fe3O4-PDMAEMA, BSA-PDMAEMA and BP-RNase A-PDMAEMA hybrid nanoparticles with miniemulsion polymerization and atom transfer radical polymerization, and attempted to apply these various hybrid nanoparticles in research field and received significant results.
Keywords/Search Tags:Miniemulsion Polymerization, Atom Transfer Radical Polymerization(ATRP), ZnO, MEH-PPV, Fe3O4, BSA, BP-RNase A, Hybrid Nanoparticles
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