Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-25T17:58:29.187Z Has data issue: false hasContentIssue false
  • English
  • Français

Process Considerations in Monolithic Aerogels

Published online by Cambridge University Press:  25 February 2011

Arlon J. Hunt  and
Kevin D. Lofftus
Arlon J. Hunt
Affiliation:
Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
Kevin D. Lofftus
Affiliation:
Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
Get access

Abstract

This paper describes important process considerations in the preparation of super-critically evacuated alcogels called aerogels. Aerogels are fine grained, open pore, low density materials that possess a variety of unusual properties and have a number of diverse applications. Factors influencing the microstructure and uniformity of alcogel monoliths are discussed. The effects of hydrolysis rate, diffusion, condensation, dispersion medium, and electrostatic interactions on particle formation and gelling are outlined. These effects are illustrated with the preparation of zirconia, mullite precursors, and silica alcogels. A theoretical model of particle interaction based on the combination of van der Waals and electrostatic double layer forces is used to interpret gelation and homogeneity. Solvent substitution and supercritical drying processes are discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 121: Symposium H – Better Ceramics Through Chemistry III , 1988 , 679
Copyright
Copyright © Materials Research Society 1988

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

Iler, R., The Chemistry of Silica: Solubility, Polymerization, Colloidal and Surface Properties, and Biochemistry (John Wiley & Sons, New York, 1979) pp. 213–44.Google Scholar
2. Schaefer, D.W., MRS Bulletin, 12 (2), 22–27 (1988).CrossRefGoogle Scholar
3. Adamson, A. W., Physical Chemistry of Surfaces, 4th ed. (John Wiley & Sons, New York, 1982) pp. 244–247.Google Scholar
4. Blanchard, N., et. al., J. of Non-Crystalline Solids, 82, pp. 205–209, (1968).CrossRefGoogle Scholar
5. Yoldas, B.E., Ceramic Bulletin, 54 (3), pp. 289–290, (1975); J. of Materiale Sci., 10, pp. 1856–1860, (1975).Google Scholar
6. Leenaars, A.F.M. and Burggraaf, A.J., J. of Colloid Interface Sci., 105 (1), pp. 27–40, (1985).CrossRefGoogle Scholar
7. Bleier, A., J. of the Am. Cer. Soc, Communications, 66 (5), pp. C79–C81, (1983).Google Scholar
8. Calvert, P.D., et. al., Better Ceramics Through Chemistry II, edited by Brinker, C. J., Clark, D. E., and Ulrich, D. R. (Mater. Res. Soc. Proc. 73 Pittsburgh, PA 1986) pp. 579–584.Google Scholar
9. Artaki, I., Zerda, T.W., and Jonas, J., Materials Letters, 3 (12), pp. 493–496, (1985).CrossRefGoogle Scholar
10. Orcel, G., Gould, R. W., and Hench, L. L., Better Ceramics Through Chemistry II, edited by Brinker, C. J., Clark, D. E., and Ulrich, D. R. (Mater. Res. Soc. Proc. 73 Pittsburgh, PA 1986) pp. 289–294.Google Scholar
11. Hunt, A.J. and Berdahl, P., Better Ceramics Through Chemistry, edited by Brinker, C. J., Clark, D. E., and Ulrich, D. R. (Mater. Res. Soc. Proc. 32, Pittsburgh, PA 1984) pp. 275–280 (LBL-16579).Google Scholar
12. Rees, A.L.G., J. Phys. Chem., 55, pp. 1340–1344 (1951).CrossRefGoogle Scholar
13. Thomas, I.L. and McCorkle, K.H., J. of Colloid and Interface Sci., 36 (1), pp. 110–118 (1971).CrossRefGoogle Scholar
14. Tewari, P.H., Hunt, A.J., Lofftus, K.D., and Lieber, J.G., Better Ceramics Through Chemistry II, edited by Brinker, C. J., Clark, D. E., and Ulrich, D. R. (Mater. Res. Soc. Proc. 73 Pittsburgh, PA 1986) pp. 195–205 (LBL-20499).Google Scholar
15. Tewari, P. H., Hunt, A. J., and Lofftus, K. D., Materials Letters, 3 (9,10), pp. 363–367 (1985).CrossRefGoogle Scholar
16. Baker, L.C.W. and Anderson, T.F., J. Am. Chem. Soc, 70, pp. 2071–2074 (1957).CrossRefGoogle Scholar
17. Geiger, G. H. and Poirier, D. R., Transport Phenomena in Metallurgy (Addison-Wesley Publishing Co., Reading, MA, 1980) pp. 441–442.Google Scholar
18. Bastacky, J. (private communication).Google Scholar