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Investigation of the Effect of Dimethylformamide Addition on Alumina Sol-Gel Formation by 27Al NMR and Rheology Measurements

Published online by Cambridge University Press:  25 February 2011

L. F. Nazar ,
L. C. Klein  and
D. Napier
L. F. Nazar
Affiliation:
Department of Chemistry, University of Waterloo, Waterloo, Canada
L. C. Klein
Affiliation:
Department of Ceramics, Rutgers- The State University of New Jersey, Piscataway, N.J.
D. Napier
Affiliation:
Department of Chemistry, University of Waterloo, Waterloo, Canada
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Abstract

The role of dimethylformamide (DMF) in the sol-gel processing of alumina at high acid/Al ratios was studied at different hydrolysis and aging temperatures by 27A1 NMR and rheology measurements. The composition of sols in which aluminum sec-butoxide was hydrolyzed in 50/50 mixtures of DMF and H2O was similar to those hydrolyzed without DMF, although the DMF sols contained a slightly lower concentration of mobile alumina species. The Al13O4 (OH)24(H2O)12 7+ cation predominated in both DMF and aqueous sols hydrolyzed at room temperatures at acid/Al ratios between 0.4 and 0.6. However, aging the room temperature DMF sols at 90°C for 24 hrs was found to cause rapid gelation whereas a similar treatment of the aqueous sols resulted in a decrease in viscosity. This gelation process was correlated with a more rapid decay of the Al13 and A1(H2O)6 3+ cations in the DMF sols. In contrast, DMF sols hydrolyzed at 90°C were found to be less viscous than their aqueous counterparts at high acid ratios.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 121: Symposium H – Better Ceramics Through Chemistry III , 1988 , 133
Copyright
Copyright © Materials Research Society 1988

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References

REFERENCES

1. Yoldas, B.E., J. Appl. Chem. Biotechnol., 23, 803 (1973)CrossRefGoogle Scholar
2. Pierre, A.C. and Uhlmann, D.R., J. Am Ceram. Soc., 70, 28 (1987).CrossRefGoogle Scholar
3. Nazar, L.F. and Klein, L. C., J. Am. Ceram. Soc., 71, C85 (1988).CrossRefGoogle Scholar
4. Orcel, G. and Hench, L.L., Mater. Res. Soc. Svmp. Proc., 32, 79 (1984).CrossRefGoogle Scholar
5. Artaki, I., Bradley, M., Zerda, T.W. and Jonas, J., J. Phys. Chem., 89, 4399 (1985) and references therein.CrossRefGoogle Scholar
6. Johannson, G., Lundgren, G., Sillen, L.G., and Soderquist, R., Acta. Chem. Scand., 14, 769 (1960).CrossRefGoogle Scholar
7. Movins, W.G. and Matwiyoff, N.A., Inorg. Chem., 6 847 (1967).Google Scholar