Hostname: page-component-669899f699-7tmb6 Total loading time: 0 Render date: 2025-04-27T00:13:15.142Z Has data issue: false hasContentIssue false
  • English
  • Français

Thermal properties of organic and inorganic aerogels

Published online by Cambridge University Press:  03 March 2011

Lawrence W. Hrubesh  and
Richard W. Pekala
Lawrence W. Hrubesh
Affiliation:
Chemistry and Materials Science Department, Lawrence Livermore National Laboratory, Livermore, California 94551-9900
Richard W. Pekala
Affiliation:
Chemistry and Materials Science Department, Lawrence Livermore National Laboratory, Livermore, California 94551-9900
Get access

Abstract

Aerogels are open-cell foams that have already been shown to be among the best thermal insulating solid materials known. This paper examines the three major contributions to thermal transport through porous materials, solid, gaseous, and radiative, to identify how to reduce the thermal conductivity of air-filled aerogels. We found that significant improvements in the thermal insulation property of aerogels are possible by (i) employing materials with a low intrinsic solid conductivity, (ii) reducing the average pore size within aerogels, and (iii) affecting an increase of the infrared extinction in aerogels. Theoretically, polystyrene is the best of the organic materials and zirconia is the best inorganic material to use for the lowest achievable conductivity. Significant reduction of the thermal conductivity for all aerogel varieties is predicted with only a modest decrease of the average pore size. This might be achieved by modifying the sol-gel chemistry leading to aerogels. For example, a thermal resistance value of R = 20 per inch would be possible for an air-filled resorcinol-formaldehyde aerogel at a density of 156 kg/m3, if the average pore size was less than 35 nm. An equation is included which facilitates the calculation of the optimum density for the minimum total thermal conductivity, for all varieties of aerogels.

Type
Articles
Information
Journal of Materials Research , Volume 9 , Issue 3 , March 1994 , pp. 731 - 738
Copyright
Copyright © Materials Research Society 1994

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.)

Article purchase

Temporarily unavailable

References

REFERENCES

1Aerogels, Springer Proc. in Physics, edited by Fricke, J. (Springer-Verlag, Heidelberg, Germany, 1986), Vol. 6.CrossRefGoogle Scholar
2Fricke, 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 (Springer-Verlag, Heidelberg, Germany, 1991), Vol. 77, p. 37.CrossRefGoogle Scholar
3Caps, R. and Fricke, J., in Aerogels, Springer Proc. in Physics, edited by Fricke, J. (Springer-Verlag, Heidelberg, Germany, 1986), Vol. 6, p. 104.CrossRefGoogle Scholar
4LeMay, J. D., Hopper, R. W., Hrubesh, L. W., and Pekala, R. W., MRS Bull. XV, 19 (1990).CrossRefGoogle Scholar
5Lu, X., Arduini-Schuster, M. C., Kuhn, J., Nilsson, O., Fricke, J., and Pekala, R. W., Science 255, 971 (1992).CrossRefGoogle Scholar
6Fricke, J., Lu, X., Wang, P., Buttner, D., and Heinemann, U., Int. J. Heat Mass Transfer 35, 2305 (1992).CrossRefGoogle Scholar
7Fricke, J., Hummer, E., Morper, H-J., and Scheuerpflug, P., in Revue de Physique Apliqueé, edited by Vacher, R., Phalippou, J., Pelous, J., and Woignier, T. (Proc. 2nd Int. Symp. Aerogels 24, C4, Les Editions de Physique, Les Ulis Cedex, 1989), p. 87.Google Scholar
8Gross, J., Fricke, J., and Hrubesh, L. W., J. Acoust. Soc. Am. 91 (4), 2004 (1992).CrossRefGoogle Scholar
9Gross, J. and Fricke, J., J. Non-Cryst. Solids 145, 217 (1992).CrossRefGoogle Scholar
10The Oxide Handbook, edited by Samsonov, G. V. (Plenum, New York, 1973).CrossRefGoogle Scholar
11Van Krevelen, D. W., Properties of Polymers (Elsevier, New York, 1990), p. 527.Google Scholar
12Gross, J., Fricke, J., Pekala, R. W., and Hrubesh, L. W., Phys. Rev. B 45 (22), 775 (1992).CrossRefGoogle Scholar
13Lu, X., Arduini-Schuster, M. C., Kuhn, J., Nilsson, O., Fricke, J., and Pekala, R. W., Science 255, 974 (1992).CrossRefGoogle Scholar
14Kaviany, M., Principles of Heat Transfer in Porous Media (Springer-Verlag, New York, 1991), p. 333.CrossRefGoogle Scholar
15Fricke, J., Lu, X., Wang, P., Buttner, D., and Heinemann, U., Science 255, 2308 (1992).Google Scholar
16Kong, F-M., Hulsey, S. S., Alviso, C. T., and Pekala, R. W., in Novel Forms of Carbon, edited by Renschler, C. L., Pouch, J. J., and Cox, D. M. (Mater. Res. Soc. Symp. Proc. 270, Pittsburgh, PA, 1992), p. 15.Google Scholar
17Tillotson, 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
18Pekala, R. W., J. Mater. Sci. 24, 3221 (1989).CrossRefGoogle Scholar
19Caps, R. and Fricke, J., in Aerogels, Springer Proc. in Physics, edited by Fricke, J. (Springer-Verlag, Heidelberg, Germany, 1986), Vol. 6, p. 110.Google Scholar
20Fricke, J., in Aerogels, Springer Proc. in Physics, edited by Fricke, J. (Springer-Verlag, Heidelberg, Germany, 1986), Vol. 6, p. 94.Google Scholar
21Martin, M., Thermalux, Inc., private communication.Google Scholar
22Lu, X., Nilsson, O., Fricke, J., and Pekala, R. W., J. Appl. Phys. 73, 581 (1993).CrossRefGoogle Scholar
23Kinoshita, K., Carbon— Electrochemical and Physicochemical Properties (John Wiley & Sons, New York, 1988), p. 12Google Scholar