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Novel Ceramic Foams from Crystals of AlCl3(Pri2O) complex

Published online by Cambridge University Press:  31 January 2011

G. S. Grader
Affiliation:
Chemical Engineering Department, Technion, Haifa 32000, Israel
G. E. Shter
Affiliation:
Chemical Engineering Department, Technion, Haifa 32000, Israel
Y. de Hazan
Affiliation:
Chemical Engineering Department, Technion, Haifa 32000, Israel
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Abstract

In this paper we report a novel process for the production of ultralight cellular ceramics. The foams are generated by the heat treatment of crystals of the aluminum chloride isopropyl ether complex [AlCl3(Pri2O)]. The crystals, which are the only foam precursor, are obtained from concentrated solutions of AlCl3, Pri2O, and CH2Cl2. The foams consist of an arrangement of closed cells, 50–300 μm in diameter, having cell walls approximately 1–2 μm thick. An exceptionally high porosity is obtained ranging from 94 to 99%, and the cellular structure is retained during heating at 1500 °C. The foaming mechanism involves two consecutive nonhydrolytic sol-gel chemical reactions and physical processes including crystal dissociation, solvation, phase separation, and foaming. While other foaming mechanisms cited in the literature utilize one or more of the processes above, no analog mechanism exists in the organic, ceramic, or metal foam production processes. The effectiveness of the process originates from an initial precursor which contains all the necessary foaming components in such a way that the application of mild heating accelerates its transformation to a solid, dry, ultralight foamed material.

Type
Articles
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1.Brockmeyer, J. W., U.S. Patent No. 4610832, Sep. 9 (1986).Google Scholar
2.Lange, F.F. and Miller, K.T., Adv. Ceram. Mater. 2, 827 (1987).CrossRefGoogle Scholar
3.Even, W.R. Jr, and Gregory, D. P., MRS Bull. XIX, 29 (1994).CrossRefGoogle Scholar
4.Fujiu, T., Messing, G. L., and Huebner, W., J. Am. Ceram. Soc. 73, 85 (1990).CrossRefGoogle Scholar
5.Wu, M. and Messing, G., J. Am. Ceram. Soc. 73, 3497 (1990).CrossRefGoogle Scholar
6.Sepulveda, P., Am. Ceram. Soc. Bull. 76, 61 (1997).Google Scholar
7.Grader, G. S. and Zuri, L., J. Am. Ceram. Soc. 76, 1809 (1993).CrossRefGoogle Scholar
8.Grader, G. S., Shter, G. E., and de Hazan, Y., Israeli Patent Application No. 123969 (1998).Google Scholar
9.Grader, G. S., de Hazan, Y., Cohen, Y., and Bravozhivotovskii, D., J. Sol-Gel. Sci. Technol. 10, 5 (1997).CrossRefGoogle Scholar
10.Comprehensive Coordination Chemistry, in 7 volumes, edited by SirWilkinson, G., FRS (Pergamon Press, Oxford, 1987).Google Scholar
11.Acosta, S., Arnal, P., Corriu, R. J. P., Leclercq, D., Mutin, P. H., and Vioux, A., in Better Ceramics Through Chemistry VI, edited by Cheetham, A.K., Brinker, C. J., and Mecartney, M. L. (Mater. Res. Soc. Symp. Proc. 346, Pittsburgh, PA, 1994), p. 43.Google Scholar
12.Acosta, S., Corriu, R. J. P., Leclercq, D., Lefevre, P., Mutin, P. H., and Vioux, A., J. Non-Cryst. Solids 170, 234 (1994).CrossRefGoogle Scholar
13.Grader, G.S., de Hazan, Y., Bravozhivotovskii, D., and Shter, G.E., J. Sol-Gel. Sci. Technol. 10, 127 (1997).CrossRefGoogle Scholar
14.Industrial Solvent Handbook, edited by Flick, E. W. (Noyes Data Corporation, Park Ridge, NJ, 1985).Google Scholar