Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-08T04:20:52.045Z Has data issue: false hasContentIssue false
  • English
  • Français

27Al MAS-NMR spectra of alumina aerogels

Published online by Cambridge University Press:  03 March 2011

Yasuyuki Mizushima ,
Makoto Hori  and
Minoru Sasaki
Yasuyuki Mizushima
Affiliation:
Colloid Research Institute, 350-1 Ogura, Yahatahigashi-ku, Kitakyushu 805, Japan
Makoto Hori
Affiliation:
Colloid Research Institute, 350-1 Ogura, Yahatahigashi-ku, Kitakyushu 805, Japan
Minoru Sasaki
Affiliation:
Colloid Research Institute, 350-1 Ogura, Yahatahigashi-ku, Kitakyushu 805, Japan
Get access

Abstract

The 27Al MAS-NMR spectra of alumina aerogels were determined. The spectra showed different profiles according to the supercritical methods used during drying. The alumina aerogel supercritically dried in a CO2 extractor (80 °C, 15.7 MPa) displayed a pentahedral-coordinated aluminum structure. On the other hand, the alumina aerogel supercritically dried in an autoclave (270 °C, 26.5 MPa) revealed no pentahedral-coordinated aluminum structure. The absence of pentahedral-coordinated aluminum was one factor for the lower temperature of transformation from the γ to the θ phase.

Type
Rapid Communications
Information
Journal of Materials Research , Volume 8 , Issue 9 , September 1993 , pp. 2109 - 2111
Copyright
Copyright © Materials Research Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Mizushima, Y. and Hori, M., Eurogel '91/Proceedings of the Second European Conference on Sol-Gel Technology, edited by Vilrainot, S., Saarbrücken, 2 - 5 June 1991.Google Scholar
2Fitzgerald, J.F., Dec, S. F., and Hamaza, A. I., Am. Mineral. 74, 1405 (1989).Google Scholar
3Selvaraj, U., Koraarneni, S., and Roy, R., J. Am. Ceram. Soc. 73 (12), 3663 (1990).CrossRefGoogle Scholar
4Maekawa, T. and Maekawa, H., J. Mineral. Jpn. 19, 339 (1990).Google Scholar
5Babonneau, F., Soraru, G. D., Thome, K. J., and Mackenzie, J. D., J. Am. Ceram. Soc. 74, 1725 (1991).CrossRefGoogle Scholar
6Yamaguchi, O., Omaki, H., Takeoka, K., and Shimizu, K., Powder and Powder Metallurgy, Jpn. 23, 143 (1976).CrossRefGoogle Scholar