Synthesis And Characterization Of Nano-metal/PVP Composites By UV Irradiating Method

Nano-Ag/PVP composite and nano-Pd/PVP composite were prepared respectively by ultraviolet irradiating at the NVP aqueous solution containing silver nitrate or palladium chloride at the room temperature,in which Ag+ ions were reduced to nano silver particles and Pd2+ ions were reduced to nano palladium particles apart,and the monomers were polymerizated simultaneously. Nano-silver/PVP composite hydrogel were prepared by adding crosslinking agent MBA in the above system.Nano-silver/polyvinylpyrrolidon(ePVP)composite materials were characterized by kinds of experimental techniques, including transmission electron microscopy(TEM), Fourier transform infrared(FT-IR),X-ray diffraction(XRD),and X-ray photo electron specstropy analysis(XPS) .TEM showed that nano silver particles were homogeneously dispersed, and the size of spheral particles was about 5 nm. The result of FT-IR suggested that the characteristic peaks of the stretching vibration absorption peak of carbonyl at 1661 cm-1 in the nano-Ag/PVP composite was shifted 12 cm-1 compared to those of the PVP polymer. XPS proved that the C1s binding energy (285.61eV) of C=O and the N 1s binding energy (399.5eV) reduced 2.18 eV and 0.38 eV respectively than the standards C1s binding energy (287.79 eV) of C=O and the standards N1s binding energy (399.8 eV).It was concluded that there was an interaction between nano silver and carbonyl oxygen and that nano silver interacted with nitrogen and carbonyl carbon through p ?Ï€conjugation effect in nano-silver/PVP.Nano-palladium/PVP composite were characterized with using the above methods. TEM showed that nano palladium particles were homogeneously dispersed in PVP matrix, and the size of spheral particles was about 10 nm. The result of FT-IR suggested that the characteristic peaks of the stretching vibration absorption peak of carbonyl in the nano-Pd/PVP composite was shifted 8 cm-1 compared to those of the PVP polymer. XRD showed that nano palladium particles were face-centered cubic crystal structure (fcc). XPS showed that there was also an interaction between nano palladium and PVP.Nano-silver/PVP composite hydrogel were characterized by a combination of experimental techniques. That the swelling ratio of nano-silver /PVP composite hydrogel was bigger than that of PVP hydrogel, which showed that the water absorption was enhanced by nano-silver. The swelling kinetics and deswelling kinetics for nano-silver/PVP composite hydrogel indicated that nano-silver increased the network aperture of hydrogel and had the effect of physical crossing points in hydrogel. The thermo- sensitive of nano-silver/PVP composite hydrogel and PVP hydrogel indicated that the thermo-sensitive of nanocomposite hydrogels was improved by nano-silver.The modified silver electrode by nano-silver/P(NVP-MMA) and nano-palladium /P(NVP-MMA) composite hydrogel respectively were prepared by dip-coating method. The results showed that the activity of the modified silver electrode was higher than that of naked silver electrode by differential pulse voltammetry. The electrochemical response of halide ions(Cl~-,Br~-,I~-) was studied by differential pulse and the results generally showed that the logarithm of halide ions concentrations is linear with the peak current in halide ions concentrations in certain extent.