Hostname: page-component-8448b6f56d-mp689 Total loading time: 0 Render date: 2024-04-23T13:04:13.937Z Has data issue: false hasContentIssue false
  • English
  • Français

Preparation of Aryl-Bridged Polysilsesquioxane Aerogels

Published online by Cambridge University Press:  25 February 2011

Douglas A. Loy ,
Kenneth J. Shea  and
Edward M. Russick
Douglas A. Loy
Affiliation:
Org. 1812, Sandia National Laboratories, Albuquerque, NM 87185
Kenneth J. Shea
Affiliation:
Department of Chemistry, University of California Irvine, Irvine, CA 92717
Edward M. Russick
Affiliation:
Org. 1812, Sandia National Laboratories, Albuquerque, NM 87185
Get access

Abstract

We report the preparation of a new class of organic/inorganic hybrid aerogels from aryl-bridged polysilsesquioxanes [1]. l,4-Bis(triethoxysilyl)benzene and 4,4'-bis(triethoxysilyl)-biphenyl were sol-gel processed to form phenyl- and biphenyl-bridged polysilsesquioxane gels (Figure 1, structures 1 and 2, respectively). The gels were then dried using supercritical carbon dioxide extraction. It was discovered that aryl-bridged polysilsesquioxane aerogels are indeed formed, but with a pronounced influence on surface area from the reaction conditions used in preparing the initial gels. Specifically, high surface aerogels ( up to 1750 m2/g) are obtained from gels prepared with either acid or base catalysts. With reduced concentrations of base catalyst, however, supercritical processing afforded phenyl-bridged xerogel-like materials, The materials were characterized by nitrogen sorption surface analysis, and by transmission electron microscopy.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 271: Symposium N – Better Ceramics Through Chemistry V , 1992 , 699
Copyright
Copyright © Materials Research Society 1992

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

[1] a) Shea, K. J.; Webster, O. W., Chem. Materials, 1, 572, (1989)CrossRefGoogle Scholar
b) Shea, K. J.; loy, D.A.; Webster, O.; Loy, D. A. in Better Ceramics Through Chemistry IV, edited by Zelinski, B.J.J., Brinker, C. J., Clark, D. E., Ulrich, D. R. (Mater. Res. Soc. Proc., 180 Pittsburgh, PA 1990, pp 975–980.Google Scholar
c) Shea, K. J.; Ioy, D.A.; Webster, O.W. J. Am. Chem. Soc. In Press, 4/92.Google Scholar
d) Shea, K. J.; Loy, D. A.; Small, James H., Webster, O. W., in preparation,Google Scholar
f) Loy, D. A., Ph. D. Dissertation, University of California at Irvine, 1991.Google Scholar
[2] Brinker, C. J. and Scherer, G.W., Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing, Academic Press, Boston, 1990, pp. 453–515.Google Scholar
[3] Kistler, S. S., Nature 122, 741 (1931).CrossRefGoogle Scholar
[4] For reviews of aerogels see: a) Fricke, J., J. Non-cryst. Solids 100, 169 (1988).CrossRefGoogle Scholar
b) Gesser, H. D. and Goswami, P. C., Chem. Reviews, 89, 765 (1989).CrossRefGoogle Scholar
[5] Pekala, R. W., J. Mater. Sci., 24(9), 3221 (1989).CrossRefGoogle Scholar
[6] Nitrogen sorption experiments were carried using a Quantachrome Autosorb Automated Gas Adsorption System; Surface areas were obtained using the five point BET method (0.02 < p/po < 0.30).Google Scholar
[7] Mulder, C. A. M. and Van Lierop, J. G. reported a silica aerogel with a surface area of 1590 m2/g in, Aerogels (Proceedings of the First International Symposium. Wurzburg, FRG, Sept. 1985), ed. by Fricke, J., Springer-Verlag, Berlin, 1986, p. 68.Google Scholar
[8] Kaiser, A., Schmidt, H., and Bottner, H., J. Membrane Sci. 22, 257 (1985).CrossRefGoogle Scholar