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Processing and Properties of Sol-Gel Derived 20 Mol% Na2 0–80 Mol% SiO2 (20N) Materials

Published online by Cambridge University Press:  15 February 2011

S. H. Wang  and
L. L. Hench
S. H. Wang
Affiliation:
Materials Science and Engineering, University of Florida Gainesville, Florida, 32611, USA
L. L. Hench
Affiliation:
Materials Science and Engineering, University of Florida Gainesville, Florida, 32611, USA
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Extract

A number of investigators [1–6] have studied the sol-gel-glass transformation and the aging, drying and densification processes involved. However, monolithic, amorphous, large scale xerogels are still difficult to produce because of insufficient understanding of basic changes in microstructure during the sol-gel-glass transformation and the chemical reactions of the precursors, solvents and catalysts used. Some papers sugqest ways of obtaining monolithic gels by (1) increasing the mechanical strength of gel by aging [7]; (2) diminishing the magnitude of capillary forces by enlarging the pore size and/or decreasing the surface energy by using surfactants [8] (3) reducino the rate of evaporation of the solvent from the pores by using a semipermeable membrane during drying [9] (4); and eliminating the pore liquid-solid interface by hypercritical evacuation [10].

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 32: Symposium B – Better Ceramics Through Chemistry I , 1984 , 71
Copyright
Copyright © Materials Research Society 1984

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References

REFERENCES

1. Brinker, C.J., Keefer, K.D., Schaefer, D.W. and Ashley, C.S., J. Non-Cryst. Solids, 48, 47–64. (1982)CrossRefGoogle Scholar
2. Schmidt, H., Scholze, H. and Kaiser, A., J. Non-Cryst. Solids, 48, 65–77 (1982).CrossRefGoogle Scholar
3. Mackenzie, J.D., J. Non-Cryst. Solids, 48, 1–10 (1982).CrossRefGoogle Scholar
4. Nogami, Masayuki and Moriya, Yoshiyo, J. Non-Cryst. Solids, 37, 191 (1980).CrossRefGoogle Scholar
5. Prassas, M., Ph.D. Thesis, Montpellier, France 1981.Google Scholar
6. Klein, L.C. and Garvey, G.J., “Monolithic Dried Gels”, J. Non-Cryst. Solids (1982).CrossRefGoogle Scholar
7. Iler, R.K. in: The Chemistry of Silica, (Wiley-Interscience, New York, 1979) Chapters 1–6.Google Scholar
8. Zarzycki, J., “Monolithic Xero-and Aerogels for Gel-Glass Processes”, in Ultrastructure Processing of Ceramics, Glasses and Composites, Hench, L.L. and Ulrich, D.R., eds.,(John Wiley & Sons, New York, 1984).Google Scholar
9. Prassas, M., Phalippou, J., Hench, L.L. and Zarzycki, J., J. Non-Cryst. Solids, 48 (1982), 79.CrossRefGoogle Scholar
10. Phalippou, J., Woignier, T., and Zarzycki, J., “Behavior of Monolithic Silica Aerogels at Temperatures Above 1000°C” in Ultrastructure Processing of Ceramics, Glasses and Composites, Hench, L.L. and Ulrich, D.R., eds. (J. Wiley & Sons, New York, 1984).Google Scholar
11. Prassas, M. and Hench, L.L., “Physical Chemical Factors in Sol-Gel Processing in Ultrastructure Processing of Glasses, Ceramics and Composites, Hench, L.L. and Ulrich, D.R., eds. (J. Wiley & Sons, Inc. New York, 1984).Google Scholar
12. Hench, L.L., “Environmental Effects in Gel Derived Materials”, in this Conference Proceedings.Google Scholar