In-situ Ultrasonic Preparation And Characterization Of Nano-Pd Particles And Polymer Composites

Preparation and dispersion technology of nano-Pd particles were mainly studied by ultrasonic wave in this paper. The mechanism of stabilization of nano-Pd particles under the existence of polyvinylpyrrolidone(PVP) or sodium dodecyl sulfate(SDS) was researched. The forming mechanism of nano-Pd/polymer composite particles was initially discussed.Monodispersed Palladium nanoparticles, which were synthesized by ultrasonic without gas protection and reductant in the palladium( II) chloride aqueous solution by the addition of a small quantity of polyvinylpyrrolidone(PVP), were characterized by means of TEM, HRTEM, FT-IR and XRD. The monodispersity and column aspect of palladium nanoparticles were observed by TEM and HRTEM respectively. The five X-ray diffraction peaks of the metallic Pd were carried out and information about the reduction of Pd(II) ions to palladium atoms Pd(0) was conformed. The stabilization of nanoparticles had been investigated using FT-IR spectroscophy, and then the result showed that the PVP can protect the metal nanoparticles via the coordination of the PVP carbonyl group to the palladium atoms and the steric effect of the PVP polymer long chain.Synchronously, the preparation of nano-Pd particles with monodisperse state was synthesized successfully in the palladium( II) chloride aqueous solution with SDS; And the stable dispersion mechanism of SDS was studied by virtue of situ ultrasonic irradiation. The products were characterized by means of TEM, FT-IR and XPS. The results indicate that SDS brings original radical which deoxidizes palladium( II) chloride by sonochemistry, and the produced functional groups coordinate the palladium particles in order to stabilize the nano-palladium in the reactional system.Based on the multifunction ultrasonic wave, with dispersion, emulsification, initiation, and the special structure of AMPS molecular chain which involves the group of hydrophility and hydrophobicity, poly- (2-acrylamido-2-methylpropanesulfonic acid)(AMPS)-co- (metheyl methacrylate)(MMA) nanoparticles composite were synthesized by in situ emulsion-free polymerization without initiator, reductant and emulsifier. The effect of monomer ratio, the pH value and output power of the ultrasonic on conversion rate of monomer, the stability of polymer emulsion, the viscosity of the polymer solution were studied respectively. The microstructure of composite particles was characterized by TEM, FT-IR, and XRD.