Kinetics of aluminum ion hydrolysis in dilute solutions

Reaction kinetics between borosilicate glass (BSG) and sapphire has been studied at temperatures from 850 °C to 950 °C. Microstructural and chemical analyses show that the nonporous interdiffusion layer is formed with Al+3 ion dissolving from sapphire and K+ diffusing from BSG onto the interface of sapphire/BSG, and that both ions are always coupled together in the reaction layer. The interdiffusion layer moves toward BSG with time and the reaction starts immediately at temperatures investigated without incubation period. The growth kinetics for the interdiffusion layer follows a parabolic rate law in the temperature range investigated, and shows an apparent activation energy in the range of 176 k–/mol. The diffusion coefficient of aluminum ion is determined from EDX analysis, and the values range from 0.7–1.4 × 10−12 at 850 °C to 3.0–6.0 × 10−12 cm2/s at 950 °C. The above results also show an activation energy close to that determined from the parabolic growth rate constants, suggesting that the mass-transport kinetics of aluminum ion from sapphire into the interdiffusion layer controls the formation process.

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Kinetics of Coil−Globule Collapse in Poly(methyl methacrylate) in Dilute Solutions below ϑ Temperatures

Macromolecules ◽

10.1021/ma991198e ◽

1999 ◽

Vol 32 (25) ◽

pp. 8399-8403 ◽

Cited By ~ 17

Author(s):

Nilhan Kayaman ◽

E. Elif Gürel ◽

Bahattin M. Baysal ◽

Frank E. Karasz

Keyword(s):

Methyl Methacrylate ◽

Dilute Solutions ◽

Poly Methyl Methacrylate ◽

Kinetics Of

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The reactions of hydrazines with trans-Dichlorobis(ethylenediamine)cobalt(III)chloride, and the isolation and kinetic studies of a Chlorobis(ethylenediamine)methylhydrazinecobalt(III) isomer

Australian Journal of Chemistry ◽

10.1071/ch9731923 ◽

1973 ◽

Vol 26 (9) ◽

pp. 1923 ◽

Cited By ~ 4

Author(s):

SC Chan ◽

CK Lee

Keyword(s):

Electron Transfer ◽

Kinetic Studies ◽

Intramolecular Electron Transfer ◽

Dilute Solution ◽

Dilute Solutions ◽

Spectroscopic Observations ◽

Acid And Base ◽

Concentrated Solution ◽

Kinetics Of ◽

Hydrolysis Of

The reactions of hydrazine, methylhydrazine, and 1,1-dimethylhydrazine with trans-dichlorobis(ethylenediamine)cobalt(III) chloride in concentrated and dilute solutions are studied. In concentrated solution, there is a reduction by hydrazine to form the insoluble polymeric [CoII(N2H4)2Cl2]n, a substitution by methylhydrazine to form chlorobis(ethylenediamine)methylhydrazinecobalt(III) chloride, and a disproportionation with 1,1-dimethylhydrazine to form tris(ethylenediamine)cobalt(III) chloride. In dilute solution, the reaction observed is a hydroxide substitution by hydrolysis of 1,1- dimethylhydrazine, a reduction to soluble cobalt(II)-ethylenediamine species with hydrazine, and a mixture of both processes for methylhydrazine. The chlorobis(ethylenediamine)methylhydrazinecobalt-(III) chloride obtained is a new complex, and is assigned a cis configuration on the basis of spectroscopic observations. The kinetics of its intramolecular electron-transfer, as well as its acid and base hydrolyses are also studied.

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