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电化学合成铜配合物的研究 总被引:3,自引:0,他引:3
采用金属铜为"牺牲"阳极,首次在无隔膜电解槽中,电化学溶解金属铜一步制备了纳米CuO前体Cu(OEt)2, Cu(OBu)2, Cu(acac)2, Cu(OEt)(acac), Cu(OBu)(acac) (acac为乙酰丙酮基).产物通过红外光谱(FT-IR)、拉曼光谱(Raman spectrum)进行表征.同时讨论了影响电合成铜醇盐及其配合物的关键因素.实验表明,防止阳极钝化,温度控制在30~50 ℃,采用有机胺溴化物为导电盐, 电极电位控制在0.8~1.2 V之间,可以提高电合成效率.实验同时表明Cu(acac)2, Cu(OEt)(acac), Cu(OBu)(acac)可作为制备含铜纳米材料前驱体. 相似文献
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Various aluminum alkoxide precursors have been used for the preparation of boehmite by hydrothermal assisted sol-gel processing. The coordination status of aluminum in solution for all precursors employed for the preparation of boehmite phase was determined by 27Al NMR and correlation between coordination status of aluminum atoms of precursors and development of boehmite phase has been investigated. Hydrothermal assisted hydrolysis of aluminum alkoxides where the aluminum atoms are four or five coordinated in solution resulted in the formation of boehmite. In contrast, hydrothermal hydrolysis of aluminum alkoxides where the aluminum atoms are six coordinated resulted in the formation of amorphous gel. Development of boehmite phase by hydrothermal hydrolysis of aluminum alkoxides at various temperatures was pursued by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. 相似文献
78.
F. Muktepavela M. Vasylyev A. Czerwinski Z. Rogulski 《Journal of Solid State Electrochemistry》2003,7(2):83-86
The humid air induced processes of embrittlement of the Sn–Al alloy and hydrogen emission have been investigated. Using the
secondary-ion mass spectrometry, X-ray, scanning electron microscopy and energy-dispersive X-ray spectrometry techniques it
was found that the brittleness is caused by a failure of phase adhesion due to accumulation of hydrogen and formation of oxidized
layers on phase boundaries during contact of the alloy with water vapour. Specific physical and electrochemical properties
of the Sn/Al phase boundary satisfy conditions for the formation of atomic hydrogen and its reaction with Sn. Electrochemical
corrosion plays an important role at the stage of formation of atomic hydrogen. The penetration of hydrogen and its accumulation
in the bulk of the alloy is due to the high energy of the phase boundary and the low energy of formation of unstable tin hydride.
Electronic Publication 相似文献
79.
V. B. Lazarev G. P. Panasjuk A. G. Panasjuk 《Journal of Thermal Analysis and Calorimetry》1992,38(1-2):141-152
Vapour phase treatment at elevated temperatures with an activating agent is an effective method of synthesis and purposeful modification of amorphous and fine-grained crystalline substances. In the systems amorphous silica-quartz and amorphous Al(OH)3 -crystalline-Al2O3 different forms of bound water are of prime importance. DTA, TG, DSC, NMR1H,29Si,27Al, IR spectroscopy, electron- and optical microscopy methods have been used. The interaction of water molecules with the base skeleton and with hydroxide groups on the surface and in the bulk of the silica is of primary significance for modification of the silica structure. The proportion of different forms of the bound water determines the integral evaporation enthalpy of water. Various properties of silica are determined by weak bound water in the surface layer of the material. In the sequence Al(OH)3 —-Al2O3 the structure transformation is observed according to the following scheme:-Al(OH)3 —-AlOOH- -Al2O3, which takes place during the vapour phase treatment with activator.
Zusammenfassung Eine Dampfphasenbehandlung bei höheren Temperaturen mit einem Aktivierungsmittel ist eine effektive Methode zur Synthese und zielgerichteten Modifizierung von amorphen und feinkörnigen kristallinen Substanzen. In den Systemen amorphes Siliziumdioxid-Quarz sowie amorphes Al(OH)3-kristallines-Al2O3 hat verschiedenartig gebundenes Wasser eine primäre Bedeutung. Bei den Untersuchungen kamen DTA, TG, DSC,1H-,29Si-,27Al-NMR, IR-Spektroskopie sowie Elektronen- und optische Mikroskopie zur Anwendung. Die Wechselwirkung von Wassermolekülen mit dem Grundgerüst und mit Hydroxidgruppen an der Oberfläche und im Innern von Silika ist für die Modifizierung der Silikastruktur von primärer Bedeutung. Der Anteil der verschiedenartig gebundenen Wasserformen bestimmt die vollständige Verdampfungsenthalpie des Wassers. Die verschiedenen Eigenschaften von Silika werden durch schwach gebundenes Wasser in der Oberflächenschicht der Substanz bestimmt. Die Umwandlung Al(OH)3 —-Al2O3 durchläuft folgendes Schema:-Al(OH)3--AlOOH--Al2O3, nach dem der Vorgang bei der Gasphasenbehandlung mit Aktivator abläuft.相似文献
80.
ICP-AES determination of trace elements after preconcentrated with p-dimethylaminobenzaldehyde-modified nanometer SiO2 from sample solution 总被引:1,自引:0,他引:1
A new method that utilizes p-dimethylaminobenzaldehyde-modified nanometer SiO2 (SiO2-p-DMABD) as a solid phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). The preconcentration conditions of analytes were investigated, including the pH value, the shaking time, the mass of sorbent, the sample flow rate and volume, the elution condition and the interfering ions. The adsorption capacity of nanometer SiO2-p-DMABD was found to be (mg g− 1) Cr(III): 6.2, Cu(II): 18.6, Fe(III): 4.7 and Pb(II): 6.0 at pH 4. The adsorbed metals were quantitatively eluted with 4 mL of 1.0 mol L− 1 HCl. According to the definition of IUPAC, the detection limits (3σ) of this method for Cr(III), Cu(II), Fe(III) and Pb(II) were 0.79, 1.27, 0.40 and 1.79 ng mL− 1, respectively. The proposed method achieved satisfied results when it was applied to the determination of trace Cr(III), Cu(II), Fe(III) and Pb(II) in biological and water samples. 相似文献