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In this article, a new method which not only can separate hydrophobic Au nanoparticles (NPs), but also obtain highly monodisperse NPs is discussed. A self-made device of two same burettes, one of which was inserted into the other, was used for separating the nanoparticles by washing the reversal micelle. The effects of separation were characterized and analyzed by micrograph of transmission electron microscope (TEM), UV-vis spectra, quartz crystal microbalance (QCM), and energy dispersive x-ray analysis (EDX). It has been shown that, the smaller nanoparticles are, the easier they are to stay at the reversal micelle and the narrower the sizes are. This method can be applied to synthesize highly monodisperse Au NPs. [ABSTRACT FROM AUTHOR]

The supported palladium catalysts were prepared by depositing Pd colloidal particles on boehmite, and then promoted by lanthanum oxide. The samples were characterized by transmission electron microscopy, powder x-ray diffraction, scanning electron microscopy, and energy dispersive x-ray spectroscopy, and studied in hydrogenation of 2-tertiary butyl anthraquinone (BAQ) to 2-tertiary butyl anthrahydroquinone (BAQH4) for H2O2 production. Compared to the catalyst prepared by metal salt impregnation method, the supported Pd nanoparticles catalyst showed high catalytic activity. Superior catalytic activity of the catalyst was related to the high dispersion of the active components and the existence of lanthanum oxide as an effective promoter, which may promote the catalytic activity both electronically and morphologically. The reaction kinetics for the catalytic hydrogenation of BAQ to BAQH2 can be described by equation r = kC BAQ  · p H 2 , and the apparent activation energy is 38 kJ · mol−1. [ABSTRACT FROM PUBLISHER]

Bimagnetic Pt3Co/Fe3O4 nanocomposite is synthesized in aqueous solution. The nanoparticles are characterized with TEM, FTIR, and magnetic measurements. The as-synthesized nanocomposite exhibits ferromagnetic properties at room temperature due to the exchange coupling between Pt3Co and Fe3O4. Magnetic properties of Pt3Co/Fe3O4 nanoparticle can be tuned by varying of the molar ratio of iron to platinum. Pt3Co/Fe3O4 nanoparticles exhibit higher saturation magnetization when the molar ratio of iron to platinum is 1. [ABSTRACT FROM AUTHOR]

The mixture of Au@CdS and CdS nanoparticles were obtained by reversed micelles method. n-Dodecanethiol was used to replace dioctylsulfosuccinate sodium salt (AOT) as a protector, and the surfactant AOT was washed away by water. By adding enthanol of different quantity, the polarity of dispersed medium was regulated and the solubility of Au@CdS and CdS nanoparticles in dispersed medium was adjusted. Consequently, the Au@CdS and CdS nanoparticles were separated effectively. Ultraviolet absorption spectra, transmission electronic microscopy (TEM), energy-dispersive X-ray analysis (EDX), and fluorescence spectra were used to characterize Au@CdS nanoparticles. [ABSTRACT FROM AUTHOR]

Palladium nanoparticles protected by PVP were obtained first by reducing PdCl2 with NaBH4 solution. Then different size palladium nanoparticles with a large size range (1.49 nm ∼ 23.26 nm) were prepared by the multi-step reduction of PdCl2 by hydrogen adsorbed on the surface of palladium nanoparticles. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) were used to characterize the nanoparticles. The increasing value of average diameter from the first to the eighth reduction reaction is about 0.58 nm, from the ninth to the fifteenth reduction reaction the value is about 2.44 nm. [ABSTRACT FROM AUTHOR]

Poly(N-vinyl-2-pyrolidone) protected Pt-core bimetallic Pt/Au-shell (Pt@Pt/Au) nanoparticles were prepared by multi-step reduction of HAuCl4 and H2PtCl6 alternately by hydrogen adsorbed on platinum atom. Transmission electronic microscopy (TEM) and x-ray diffraction (XRD) were used to characterize Pt@Pt/Au nanoparticles. The structure of the shell of the nanoparticles seems to be the Au-Pt solid solution. [ABSTRACT FROM AUTHOR]