Theoretical analysis of XANES for aqueous aluminum salt solutions

Experiments were made to determine the relative amounts of solid phase hydroxyaluminum to polynuclear ionic hydroxyaluminum formed, according to methods developed by one of the authors, during titrations of dilute AlCl3 solutions with a base. With both 10−3 and 10−2 M AlCl3 solutions, and with both fast (less than 5 minutes) and slow (12 hours) titrations, the solid phase and the polynuclear ions were present at each degree of neutralization at which measurements were made. During the greater part of the titrations the solid phase was the major product with the fast titrations, and the polynuclear ions were the major product with the slow titrations. Beyond about 80% neutralization the polynuclear ions began to decrease in concentration until at 100% the solid phase approached 100% of the products regardless of the rate of titration. There was a considerable amount of Cl associated with the solid phase during most of each titration, but the Cl/Al molar ratio of the solid approached zero as neutralization approached 100%.

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ChemInform Abstract: ULTRAVIOLET SPECTRA OF ALUMINUM SALT SOLUTIONS

Chemischer Informationsdienst ◽

10.1002/chin.198223012 ◽

1982 ◽

Vol 13 (23) ◽

Author(s):

J. F. MCINTYRE ◽

R. T. FOLEY ◽

B. F. BROWN

Keyword(s):

Aluminum Salt ◽

Salt Solutions ◽

Ultraviolet Spectra

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Hydrolysis of Aluminum -Are All Gels Created Equal?

MRS Proceedings ◽

10.1557/proc-180-97 ◽

1990 ◽

Vol 180 ◽

Cited By ~ 30

Author(s):

T. E. Wood ◽

A. R. Siedle ◽

J. R. Hill ◽

R. P. Skarjune ◽

C. J. Goodbrake

Keyword(s):

Thermal Evolution ◽

Mas Nmr ◽

Aluminum Salt ◽

Salt Solutions ◽

Transition Alumina ◽

Aluminum Ion ◽

Hydrolysis Of

ABSTRACTThe nuclearity and structure of aluminum cations generated by the hydrolysis of aluminum salt solutions depends markedly on the method of preparation. This speciation affects not only the thermochemistry of processes leading to ceramics, but the microstructures of the ceramics themselves. A brief review of aluminum ion hydrolysis is presented along with a study of the thermal evolution of gels derived from aluminum salt solutions via several different hydrolysis methods. The observation of 5 - coordinate aluminum in a bulk transition alumina by MAS-NMR is reported. A new, high defect precursor of η-alumina dubbed “high-5 alumina” is described and the far reaching implications of this discovery are discussed.

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Infrared Spectra of Aluminum Salt Solutions

Applied Spectroscopy ◽

10.1366/0003702824638746 ◽

1982 ◽

Vol 36 (2) ◽

pp. 128-136 ◽

Cited By ~ 9

Author(s):

J. F. McIntyre ◽

R. T. Foley ◽

B. F. Brown

Keyword(s):

Absorption Band ◽

Infrared Spectra ◽

Molecular Level ◽

Chemical Reactivity ◽

Aluminum Salt ◽

Salt Solutions ◽

Absorption Bands ◽

Bending Mode ◽

Structural Differences ◽

Aluminum Surfaces

Aluminum salt solutions activate metallic aluminum surfaces at different rates. The objective of this investigation was to attempt to establish whether or not structural differences at the molecular level could account for the chemical reactivity. The infrared spectra of various concentrations of aluminum chloride, aluminum nitrate, aluminum perchlorate, and aluminum sulfate were measured. The spectra included several general features: (1) a broadening of the OH stretching band of water, (2) a splitting of the OH stretch of water into several absorption bands, (3) the emergence of a new absorption band at 2400 cm−1 (related to dimer formation), (4) splitting of the NO3− absorption band at 1370 cm−1 (5) occasional splitting of the OH bending mode of water, (6) no direct evidence of anion-cation interaction for AlCl3, Al(CIO4)3, and Al2(SO4)3. In general, there was no difference at the molecular level between these aluminum salt solutions that would account for differences in chemical reactivity.

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