| Because of the particular nanometer effects of precious metal nanometer-materials, precious metal nanometer-materials have the performance of optical, electrical, magnetic and mechanical and biological medicine. The precious metal nanometer-materials have been applied in many fields such as electronics, medicine, chemical industry, military, aviation and so on. due to it have the properties about the higher heat conductivity, catalytic and antibacterial. But the metal nanoparticles have very powerful surface action, the problem of agglomeration often exists when these metal nanoparticles are used. Then the metal nanoparticles could lose the unique performance. Waterborne polyurethane as a kind of polymer, which has beenwidely used in our life beacause of the advantages about non-toxic, non-polluting, easy processing and energy saving etc. Using water polyurethane as a stabilizer, let it composite with precious metal nanoparticles, then a new kind of metal/polymer nanocomposites was prepared. The metal/polymer nanocomposites not only keep the unique properties in opticcs, elctricity, magnetism, thermology and improve the dispersibility and stability about the precious metal nanoparticles, but also let the precious metal nanoparticles possess the performance of polymer. The application fields and effect of precious metal nanoparticles have been greatly expanded and improved.The main research contents and results were as follows:(1) Silver nanowires were successfully synthesized by hydrothermal method using copper chloride, ethylene glycol, poly(vinylpyrrolidone, PVP), silver nitrate as raw materials. The effects of reaction temperature, reaction time and concentration of copper chloride on the sample morphology were investigeted. The structure and performance of the as-prepared silver nanowires were characterized by X-ray diffraction(XRD) and scanning electron microscopy(SEM). Meanwhile, the as-prepared silver nanowires were used as work electrode to the electrochemical luminescence(ECL) of Ru(bpy)32+for research its catalytic mechanism. The results show that the as-prepared silver nanowires had face-centered cubic structure, with length up to13μm and the ratio of length-diameter was75under the temperature of165℃, the reaction time of1h and the concentration of CuCl2of4mmol/L. Compared with Ag bulk electrode, the silver nanowires electrode was more suitable for the work electrode of ECL of Ru(bpy)32+because of the high specific surface area and unique catalytic properties.(2) Silver nanoparticles and the surface modified gold nanoparticles were prepared by chemical reduction method using silver nitrate (AgNO3), sodium borohydride (NaBH4), chloroauric acid, sodium citrate and dithioerythritol as the raw materials. At same time, the anionic waterborne polyurethane and cationic waterbome polyurethane were synthesized by means of the method of self-emulsion process, using polyester polyols (YA7720), isophorone diisocyanate,2,2-dimethylol propionic acid or N-methyl diethanolamine as main raw materials. Using the direct blending method and the situ synthesis method to prepare the composite materials of Ag/WPU and Au/WPU. The composite materials were characterized by infrared spectrum analysis(FTIR), ultraviolet visible spectrum(UV), transmission electron microscope(TEM) and X-ray photoelectron spectroscopy(XPS). In addition, the Oxford cup method was used to test the antibacterial property of the composite materials. The results indicated that gold nanoparticles and silver nanoparticles were presented as regular spherical in the nanometer size. Waterborne polyurethane could not only stable the metal nanoparticles but also improve their dispersability. The composite materials have a better antibacterial property compared with the metal nanoparticles without compounded with the waterborne polyurethane. |
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