材料期刊网

THERMODYNAMIC TREATMENT OF MULTICOMPONENT SYSTEMS USING INTERACTION PARAMETERS

Z. T. Ma , J Ohser and D. Janke(Institute of Iron and Steel Technology , Freiberg University of Mining and Technology , Germany )

金属学报(英文版)

The partial thermodynamic functions of solvent and solutes in multicomponent systems have been expressed in terms of the interaction parameters. The corresponding analytical expressions of the activity coefficients of solvent and solutes enable to de scribe the thermodynamic properties of multicomponent systems. The advantages of this treatment are found in its thermodynamic consistency and a rather small influ ence of the higher order interaction parameters on the properties of the systetms.

关键词: thermodynamics; activity; model

Nobel Prize for Our Advisor, Gerhard Ertl, Germany

催化学报

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Controlled synthesis of cobalt flowerlike architectures by a facile hydrothermal route

European Journal of Inorganic Chemistry

Cobalt flowerlike architectures composed of hexagonal nano-platelets have been synthesized by a simple hydrothermal. reduction method. The architectures are fabricated by the reaction Of COCl2 with NaOH at 140-180 degrees C in the presence of sodium dodecyl benzenesulfonate (SDBS), with NaH2PO2 center dot H2O as reducing agent. The diameters of the flowers range from 8 to 10 mu m, and the average thickness of the hexagonal sheets is about 100 nm. Higher reaction temperatures and the proper concentration of sodium hydroxide (NaOH) are key requirements for the fabrication of the flowerlike architectures. A growth mechanism for these architectures is proposed on the basis of the characterization by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The magnetic hysteresis loops at 5 K and 295 K of the cobalt flowerlike architectures show ferromagnetic characteristics with coercivities of 371 Oe and 197 Oe, respectively. Our work may shed light on the designed fabrication of complex 3D architectures of other materials. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008.

关键词: hydrothermal synthesis;cobalt;nanostructures;magnetic properties;gold nanoparticle arrays;anisotropic growth;self-organization;nanoplatelets;superlattices;nanocrystallites;superstructures;nanostructures;construction;aggregation

Hydrothermal Synthesis of Three-Dimensional Hierarchical CuO Butterfly-Like Architectures

European Journal of Inorganic Chemistry

Uniform 3D hierarchical CuO butterfly-like architectures were fabricated by a surfactant-assisted hydrothermal oriented attachment route. This route included the formation of CuO butterfly-like architectures in a solution of cupric chloride (CuCl(2)center dot 2H(2)O) and sodium hydroxide (NaOH) at 100 degrees C for 15 h by using sodium dodecyl benzenesulfonate (SDBS) as surfactant. The as-prepared CuO architecture was characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The CuO butterfly-like architectures, with lengths of about 6 pm and widths of 2-4 mu m, were assembled from several tens of oriented attachment rhombic nanosheets with a thickness of about 60 nm. A growth mechanism for the formation of the CuO butterfly-like architectures was proposed on the basis of time-dependent. experiments. The synthetic parameters such as reaction temperature, the concentration of sodium hydroxide and reaction time all affected the morphology of the CuO architectures. The synthetic strategy could be extended to assemble 3D architectures of other materials. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451. Weinheim, Germany, 2009)

关键词: Hydrothermal synthesis;Copper oxide;Nanostructures;Self-assembly;large-scale synthesis;catalytic-properties;cu(oh)(2) nanowires;oriented attachment;formation mechanism;room-temperature;field-emission;hollow spheres;simple route;nanostructures