Fabrications of Dendrimer/Metal Oxide Nanoparticle Hybrids and Their Environmental Low Load Assemblies

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The purpose of the research subject is the synthesis of dendrimer-protected metal oxide nanoparticles at the optimum conditions, the fabrication of their one-dimensional and two-dimensional assemblies and their hybridization with linear polymers for the clarification of functionality as multifunctional sensors, environmental low load systems, or metal oxide devices. Titanium oxide nanoparticles were synthesized using hydrophilic dendritic polymers, poly(amido amine) dendrimer and poly(amido amine) dendrons with siloxy focal point and long alkyl chain spacers, as a protector. Nanoparticles were stably dispersed in water without secondary aggregation. The size and stabilization of nanoparticles depended on the ratio of metal ions with dendritic polymers rather than the dendrimer generation, tha is, nanoparticles with small size and stable dispersion were produced at high ratio of dendritic polymers. The ability of dendritic polymeer-protected TiO_2 nanoparticles as a photocatalyst for th … More e photodegradation of a water-pollutant was higher than that of nonprotected nanoparticle and superior at higher generation. It was suggested that the dendritic polymers protecting TiO_2 nanoparticle have enough void volume to conserve guest molecules and behave effectively as a reservoir of guest molecules besides as a protector. It can be concluded that the synthesized titanium dioxide nanoparticles can be expected as a environmental load-lowering materials, since they are effective as a photocatalytic compound in water.ZnO nanoparticles protected by siloxy focal dendron were synthesized by adding a NaOH ethanol solution at 〜0℃ to a zinc acetate ethanol solution. It was confirmed from X-ray photoelectron spectroscopy that Zn-O-Si covalent bond was formed in dendron-protected ZnO nanoparticles. The peak for Si-O-Si bond remarkably appeared instead of the peak for C-O-Si bond. These facts indicate that aggregates between dendrons bonding to ZnO nanoparticles coexist with self aggregates of dendrons. Additionally, in order to maintain dispersibility of ZnO nanoparticles, G3 dendron-ZnO nanoparticle composites were doped in a membrane of poly 2-hydroxyethyl methacrylate. Nanoparticles were dispersed well in the membrane. This achievement is a step for developing hierarchic organization of metal oxide/dendron hybrid to photodegradation system of environmental low load type. Less