Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-29T06:19:07.119Z Has data issue: false hasContentIssue false
  • English
  • Français

Inorganic and Organic Aerogels

Published online by Cambridge University Press:  29 November 2013

Get access

Extract

Aerogels are a special class of open-cell foams derived from the supercritical drying of highly cross-linked inorganic or organic gels. These materials have ultrafine cell/pore sizes (less than 1,000 Å), continuous porosity, high surface area (400–1000 m2/g), and a microstructure composed of interconnected colloidal-like particles or polymeric chains with characteristic diameters of 100 Å. This microstructure is responsible for the unusual optical, acoustic, thermal, and mechanical properties of aerogels. For example, aerogels can be prepared as transparent, porous solids because their ultrafine cell/pore size minimizes light scattering in the visible spectrum. Figure 4.1 shows the different aerogels that will be discussed in this article.

The hydrolysis and condensation of metal alkoxides is the most common synthetic route for the formation of inorganic aerogels. Inorganic aerogels have been prepared from monomers such as tetraisopropoxy titanate, aluminum secbutylate, and zirconium isopropoxide. Nevertheless, the majority of scientific research has concentrated on the sol-gel polymerization of tetramethoxysilane (TMOS), or the less toxic tetraethoxysilane (TEOS). The resultant silica aerogels are being investigated for applications ranging from window insulation to the collection of hypervelocity partis cles in space.

The sol-gel polymerization of a multifunctional monomer in solution, leading to the formation of an aerogel, is not unique to metal alkoxides. Organic reactions that proceed through a sol-gel transition have been discovered recently.

Type
Technical Feature
Information
MRS Bulletin , Volume 15 , Issue 12 , December 1990 , pp. 30 - 36
Copyright
Copyright © Materials Research Society 1990

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

1.Fricke, J., Sci. Am. 258(5) (1988) p. 92.CrossRefGoogle Scholar
2.Fricke, J., in Sol-Gel Science and Technology, edited by Aegerter, M.A., Jafelicci, M., Souza, D.F., and Sanotto, E.D. (World Sci. Publ., New Jersey, 1989) p. 482.Google Scholar
3.Teichner, S.J., Nicolaon, G.A., Vicarini, M.A., Gardes, G.E.E., Adv. Coll. interf. Sci. 5 (1976) p. 245.CrossRefGoogle Scholar
4.Fricke, J., editor, Aerogels (Springer-Verlag, New York, 1986).CrossRefGoogle Scholar
5.Henning, S. and Svensson, L., Physica Scripta 23 (1981) p. 698.Google Scholar
6.Brinker, C.J., Keefer, K.D., Schaefer, D.W., and Ashley, C.S., J. Non-Cryst. Solids 48 (1982) p. 47.CrossRefGoogle Scholar
7.Brinker, C.J., Keefer, K.D., Schaefer, D.W., Assink, R.A., Kay, B.D., and Ashley, C.S., J. Non-Cryst. Solids 63 (1984) p. 45.CrossRefGoogle Scholar
8.Pekala, R.W. and CAlviso, T., in Better Ceramics Through Chemistry IV, edited by Brinker, C.J., Clark, D.E., Ulrich, D.R., and Zelinski, B.J. (Mater. Res. Soc. Symp. Proc. 180, Pittsburgh, PA, 1990) p. 791.Google Scholar
9.Pekala, R.W., J. Mat. Sci. 24 (1989) p. 3221.CrossRefGoogle Scholar
10.Pekala, R.W. and Kong, F.M., J. de Physique Coll. Suppl. 50(4) (1989) p. C4–C33.Google Scholar
11.Pekala, R.W. and Kong, F.M., Polym. Preprints 30(1) (1989) p. 221.Google Scholar
12.Brinker, C.J. and Scherer, G.W., J. Non-Cryst. Solids 70 (1985) p. 301.CrossRefGoogle Scholar
13.Tillotson, T.M., Hrubesh, L.W., and Thomas, I.M., in Better Ceramics Through Chemistry III, edited by Brinker, C.J., Clark, D.E., and Ulrich, D.R. (Mater. Res. Soc. Symp. Proc. 121, Pittsburgh, PA, 1988) p. 685.Google Scholar
14.Tillotson, T.M. and Hrubesh, L.W., in Better Ceramics Through Chemistry IV, edited by Brinker, C.J., Clark, D.E., Ulrich, D.R., and Zelinski, B.J. (Mater. Res. Soc. Symp. Proc. 180, Pittsburgh, PA, 1990) p. 309.Google Scholar
15.Hrubesh, L.W., Tillotson, T.M., and Poco, J.F., in Better Ceramics Through Chemistry IV, edited by Brinker, C.J., Clark, D.E., Ulrich, D.R., and Zelinski, B.J. (Mater. Res. Soc. Symp. Proc. 180, Pittsburgh, PA, 1990) p. 315Google Scholar
16.Werstler, D.D., Polymer 27 (1986) p. 757.CrossRefGoogle Scholar
17.Sebenik, A., Osredkar, U., and Vizovisek, I., Polymer 22 (1981) p. 804.CrossRefGoogle Scholar
18.Schaefer, D.W., Science 243 (1989) p. 1023.CrossRefGoogle Scholar
19.Schaefer, D.W., MRS Bulletin 13(2) (1988) p. 22.CrossRefGoogle Scholar
20.Pekala, R.W. and Ward, R.L., Polym. Preprints 31(1) (1990) p. 167.Google Scholar
21.Blank, W.J., J. Coatings Tech. 51(656) (1979) p. 61.Google Scholar
22.Updegraff, I.H., in Encyclopedia of Polymer Science and Engineering (John Wiley & Sons, New York, 1985) p. 752.Google Scholar
23.Hench, L.L. and Fosmoe, A., in Multifunctional Materials, edited by Ulrich, D.R., Buckley, A.J., Karasz, F.E., and Gallagher-Daggitt, G. (Mater. Res. Soc. Symp. Proc. 175, Pittsburgh, PA, 1990) p. 23.Google Scholar
24.Mandelbrot, B.B., The Fractal Geometry of Nature (Freeman, San Francisco, 1982).Google Scholar
25.Teixeira, J., J. Appl. Cryst. 21 (1988) p. 781.CrossRefGoogle Scholar
26.Martin, J.E. and Hurd, A.J., J. Appl. Cryst. 20 (1988) p. 61.CrossRefGoogle Scholar
27.Schaefer, D.W., Wilcoxon, J.P., Keefer, K.D., Bunker, B.C., Pearson, R.K., Thomas, I.M., and Miller, D.E., AIP Conf. Proc: Phys. and Chem. Porous Media II 154 (1987) p. 63.CrossRefGoogle Scholar
28.Schaefer, D.W. and Keefer, K.D., Phys. Rev. Lett. 56(20) (1986) p. 2199.CrossRefGoogle Scholar
29.Gibson, L.J. and Ashby, M.F., Proc. Royal Soc. Lond. 382(A) (1982) p. 43.Google Scholar
30.Woignier, T., Phalippou, J., and Vacher, R., J. Mater. Res. 4(3) (1989) p. 688.CrossRefGoogle Scholar
31.Meinecke, E.A. and Clark, R.C., Mechanical Properties of Polymeric Foams (Technomic Publ., Westport, CT, 1973).Google Scholar
32.LeMay, J.D., Pekala, R.W., and Hrubesh, L.H., Pacific Polym. Preprints 1 (1989) p. 295.Google Scholar
33.Pekala, R.W., Alviso, C.T., and LeMay, J.D., J. Non-Cryst. Solids, in press; Lawrence Livermore National Laboratory Report No. UCRL-102969, February, 1990.Google Scholar
34.LeMay, J.D., Tillotson, T.M., Hrubesh, L.W., Pekala, R.W. in Better Ceramics Through Chemistry IV, edited by Brinker, C.J., Clark, D.E., Ulrich, D.R. and Zelinski, B.J (Mater. Res. Soc. Symp. Proc. 180, Pittsburgh, PA, 1990) p. 321.Google Scholar