Titanates aluminium

Unter den metallorganischen Verbindungen haben die Verbindungen der Alkalimetal-le, des Magnesiums, Bors, Aluminiums, Zinks und Titans als Reduktionsmittel gewisse Bedeutung. 

Ti-Al]-beta (Si/Al < 150) Prehydrolysis method-conventional method using amorphous silica (Arosol 200), tetraethyl titanate, sodium aluminate/aluminium nitrate as sources of Si, Ti, and Al, respectively. Crystallization at 408 K by rotation (60rpm) zeolite yield <7%. 

Mit Murexid reagieren ferner Eisen(II) und (III), Mangan(II) und Zinn(ll), ohne daB jedoch hiervon analytischer Gebrauch gemacht worden ware. Mit Blei- und Uranylion tritt nur sehr schwache Reaktion ein, wahrend Quecksilber, Aluminium, Titan und Chrom ohne EinfluB sind (163). 

Die Reaktion gelingt auch bei Abwesenheit einer a-Phenylthio-Gruppe in Gegenwart von Lewis-Sauren [z. B. Aluminium-, Zinn(IV)-, Titan(IV)-chlorid] z.B.2 ... 

Sekundare und tertiare, aliphatische Nitro-Verbindungen, die durch eine Allyl-, 1 -Cycloalkenyl- oder Phenylthio-Gruppe desaktiviert sind, lassen sich mit Cyan-trimethyl-silan in Gegenwart einer Lewis-Saure [z. B. Zinn(IV)-, Aluminium- oder Titan(IV)-chlorid] durch... 

Urine (5 ml) urine spiked with 0.2% (v/v) isopropylamine is placed in a screw-capped 15-ml vial [28]. Pelleted potassium hydroxide (3 g) is added before sealing the vial with an airtight polytetrafluoroethylene-lined septum cap. Potassium hydroxide raises the pH of the sample to ensure that the amines are present as volatile bases. The vial is heated in an aluminium block at 90 C for 20 min. While still in this block, 2 ml head-space gas is withdrawn through the septum with a disposable syringe and injected immediately on the gas chromatography column. The operating temperatures of the column, injector port and detector unit are 70 C isothermal, 150 C and 200 C, respectively, with nitrogen carrier gas at 60 ml/min. This allows quantification of TMA and other amines. TMA N-oxide is measured after quantitative reduction into TMA. For this, titanous chloride (30%, w/v 0.2 ml) is added to 2 ml urine in a screw-capped vial and incubated for 30 min at room temperature. The sample is then diluted ten-fold with distilled water and analysed as described above. The result represents the sum of TMA and TMA N-oxide present in the sample. 

Um sich ein Bild liber die Konfiguration dieses 1 1-Komplexes zu machen, muB beriicksichtigt werden, daB sowohl Titan, als auch Aluminium zur Ausbildung von bimetallischen. .Briickenkomplexen"... 

Dieser kinetische Behind unterstreicht die Bedeutung der Aluminium-briicke fiir die Stabilitat der Titan-Kohlenstoff-Bindung. Solange alle Liganden am Aluminium Chloratome sind, ist die Bindung Ti-C relativ stabil.undnureinesehrlangsameReduktion wird beobachtet.Ersetzt man... 

Thermolysis of tin and lead alkoxozirconates leads to the formation of metals. The mass-spectral data indicate the presence ofbarium and aluminium derivatives in the gas phase, but no preparative data are accessible for them. The major application of zirconium and hafnium alkoxides lies now in the sol-gel technology of zirconate-titanate and solid solutions Zr02-Y203 (see Section 10.3), Except in the synthesis of oxide materials, the alkoxides of zirconium and hafnium are traditionally used in the polymer chemistry, where they are applied as the components in catalysts [1278, 1269] and as additives to polymers, improving their characteristics [825, 1403] and so on. Already in 1930s Meerwein has proposed the use of zirconium alkoxides for the reduction of aldehydes intoprimary alcohols (Meerwein-Schmidt reaction) [1420],... 

For most particulate composites the mismatch between the particles and the matrix is more important than the anisotropy of either component (though alumina/aluminium titanate composites provide a notable exception and are described below). The main features of the stresses can therefore be understood in terms of a simple elastic model assuming thermoelastic isotropy and consisting of a spherical particle in a concentric spherical shell of matrix with dimensions chosen to give the appropriate volume fractions. The particles are predicted to be under a uniform hydrostatic stress, ap after cooling. If the particles have a larger thermal expansion coefficient than the matrix, this stress is tensile, and vice versa. For small particle volume fractions the stress... 

Plot of strength versus indentation load for alumina with various grain sizes and alumina/aluminium-titanate composite. The data points and solid line are from the composite. The other lines are for alumina with various grain sizes A, 2.5 pm, experimental B, 6 pm, interpolated C, 80 pm, experimental (reproduced from Bennison et al. [7] by kind permission of Taylor and Francis Ltd (http // www.tandf.co.uk/journals). 

Alumina/aluminium titanate and alumina-zirconia/ aluminium titanate systems... 

Low, I.M. (1998a) Processing of an in-situ layered and graded alumina-aluminium titanate composites. Mater. Res. Bull. 33, 1475-1482. 

Low, I.M. (1998b) Synthesis and properties of in-situ layered and graded aluminium titanate/alumina composites. J. Aust. Ceram. Soc. 34, 250-255. 

Manurung, P. (2001) Microstructural design and characterisation of alumina/aluminium titanate composites. Ph.D Thesis, Curtin University of Technology, Perth, Australia. 

Padture, N.P., Bennison, S.J. Chan, H.M. (1993) Flaw-tolerance and crack-resistance properties of alumina and aluminium titanate composites with tailored microstructures. J. Am. Ceram. Soc. 76, 2312-2320. 

Runyan, J.L. Bennison, S.J. (1991) Fabrication of flaw-tolerant aluminium-titanate-reinforced alumina. J. Eur. Ceram. Soc. 7, 93-99. 

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