Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-09T20:22:57.151Z Has data issue: false hasContentIssue false
  • English
  • Français

A Rapid Supercritical Extraction Process for the Production of Silica Aerogels*

Published online by Cambridge University Press:  10 February 2011

J. F. Poco ,
P. R. Coronado ,
R. W. Pekala  and
L. W. Hrubesh
J. F. Poco
Affiliation:
Chemistry & Materials Science Department, Lawrence Livermore National Laboratory, Livermore, CA94550 [email protected]
P. R. Coronado
Affiliation:
Chemistry & Materials Science Department, Lawrence Livermore National Laboratory, Livermore, CA94550 [email protected]
R. W. Pekala
Affiliation:
Chemistry & Materials Science Department, Lawrence Livermore National Laboratory, Livermore, CA94550 [email protected]
L. W. Hrubesh
Affiliation:
Chemistry & Materials Science Department, Lawrence Livermore National Laboratory, Livermore, CA94550 [email protected]
Get access

Abstract

Silica aerogels are a special class of porous materials in which both the pore size and interconnected particle size have nanometer dimensions. This structure imparts unique optical, thermal, acoustic, and electrical properties to these materials. Transmission electron microscopy and small angle x-ray scattering show that this nanostructure is sensitive to variations in processing conditions that influence crosslinking chemistry and growth processes prior to gelation. Recently, Lawrence Livermore National Laboratory (LLNL) has demonstrated that a Rapid Supercritical Extraction (RSCE) process can be used to prepare near-net shape silica aerogels in hours rather than days. Preliminary data from RSCE silica aerogels show that they have improved mechanical properties and slightly lower surface areas than their conventionally dried counterparts, while not compromising their optical and thermal performance.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 431: Symposium P – Microporous and Macroporous Materials , 1996 , 297
Copyright
Copyright © Materials Research Society 1996

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.)

Footnotes

*

Work performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48

References

1. Fricke, J. and Emmerling, A., in Chemistry. Spectroscopy, and Applications of Sol-Gel Glasses, edited by Reisfeld, R. and Jorgensen, C.K., (Springer Series on Structure and Bonding, Vol.77, Springer-Verlag, Heidelberg, Germany, 1991), p. 37.Google Scholar
2. Scherer, G.W., J. Am. Ceram. Soc. 69, 473 (1986). G.W. Scherer, in Ultrastructure Processing of Advanced Materials, edited by D.R.Google Scholar
3. Uhlmann, and Ulrich, D.R., (J. Wiley & Sons, N.Y., 1992), p. 181. C.J. Brinker and G.W. Scherer, Sol-Gel Science (Acad. Press, N.Y., 1990), p. 413.Google Scholar
4. Scherer, G.W., J. Non-Cryst. Solids 145, 33 (1992).Google Scholar
5. Scherer, G.W., Hdach, H. and Phalippou, J., J. Non-Cryst. Solids 130, 157 (1991).Google Scholar
6. G Scherer, W., Sol-Gel, J. Science Science and Technology 3, 127 (1994);Google Scholar
7. Woignier, T., Scherer, G.W. and Alaoui, A., Science Science and Technology, 3 p.141 (1994). J. Phalippou, G.W. Scherer, T. Woignier, D. Bourret and R.Sempe're',Google Scholar
8. J. Non-Cryst. Solids 186, 64 (1995); vanBommel, M.J. and deHaan, A.B., Science Science and Technology, 3, p.78 (1994). G.W. Scherer, S.A. Pardenek, and R.M. Swiatek, J. Non-Cryst. Solids 107, 14 (1988).Google Scholar
9. Hrubesh, L.W., Tillotson, T.M., and Poco, J.F., in Chemical Processing of AdvancedGoogle Scholar
10. Materials, edited by Hench, L.L. and West, J.K., (J. Wiley & Sons, N.Y., 1992), p. 19.Google Scholar