Skip to main content Accessibility help
×
Home

In-Situ Pore Structure Analysis During Aging and Drying of Gels

  • Douglas M. Smith (a1), Pamela J. Davis (a1) and C. Jeffrey Brinker (a2)

Abstract

The use of NMR relaxation measurements for the in-situ study of pore structure evolution during gel aging and drying is illustrated. The change in the pore size distribution and surface area of both wet and dried gels is examined as a function of aging conditions including temporal aging, thermal aging, changing pH, and changing pore fluid. The effect of pore fluid pH on dissolution/reprecipitation in ordered packings of monodisperse silica spheres is also examined as a model system for particulate gels. As expected, the pore size distribution narrows with increasing time of treatment in high pH pore fluids. Interpretation of high pH results for the wet state is complicated by a microporous layer which forms on colloidal silica resulting in significantly larger wet surface area as compared to the final dried material. Narrowing of the pore size distribution, which is of interest for maximizing drying rates, is maximized in the least time by using either high pH or repeated ethanol washes for the base-catalyzed gel (B2) used.

Copyright

References

Hide All
1. Schaefer, D.W., and Keefer, K.D., Better Ceramics Through Chemistry I, Eds. Brinker, , Clark, , Ulrich, , Materials Research Society Pittsburgh, Ultrastructure Processing Of Advanced Ceramics, Eds. Mackenzie and Ulrich, J. Wiley and Sons, New York, (1988)
2. Keefer, K.D., in Better Ceramics Through Chemistry I, Eds. Brinker, , Clark, , Ulrich, , Materials Research Society, Pittsburgh, 15, (1984)
3. Brun, M., Lallemand, A., Quinson, J., and Eyraud, C., Thermochim. Acta, 1977, 21, 59.
4. Eyraud, C., Quinson, J.F., and Brun, M., in Characterization of Porous Solids, Eds. Unger, , Rouquerol, , Sing, , Elsevier, Amsterdam, (1988).
5. Gallegos, D.P., Munn, K., Smith, D.M., and Stermer, D.L., J. Colloid Interface Sci., 1987, 119, 127.
6. Bhattacharja, S., D'Orazio, F., Tarczon, J.C., Halperin, W.P., and Gerhardt, R., J.Am.Ceram.Soc., 1989, 72, 2126.
7. Brownstein, K.R., and Tarr, C.E., J. Mag. Resonance, 1977, 26, 17.
8. Ewing, B., Davis, P.J., Majors, P.D., Drobney, G., Smith, D.M., and Earl, W.E., J. Am. Ceram. Soc., in Press.
9. Majors, P., Smith, D.M., and Davis, P.J., Aiche Journal, Submitted.
10. Scherer, G.W., J. Non-Cryst. Solids, 1988, 100, 77.
11. Mizuno, T., Nagata, H., and Manbe, S., J. Non-Cryst. Solids, 1988, 100,236.
12. Brinker, C.J., and Scherer, G.W., Sol-Gel Science, Academic Press, New York,1990.
13. Quinson, J.F., Dumas, J. Serughetti, J., J. Non-Cryst. Solids, 1986, 79, 379.
14. Quinson, J.F., Dumas, J., Chatelut, M., Serughetti, J., Guizard, C., Larbot, A., and Cot, L., J. Non-Cryst. Solids, 1989, 113, 14.
15. Glaves, C.L., Brinker, C.J., Smith, D.M., and Davis, P.J., Chem. Materials, 1989, 1, 34.
16. Brinker, C.J., Keefer, K.D., Schaefer, D.W., Ashley, C.S., J. Non-Cryst. Solids, 1982, 48, 47.
17. Stober, W., Fink, A., and Bohn, E., J.Colloid Interface Sci., 1968, 26,62.
18. Gallegos, D.P., Smith, D.M., J. Colloid Interface Sci., 1988, 122,143.
19. Davis, P.J., Gallegos, D.P., and Smith, D.M., Pow. Tech., 1987, 53, 39.
20. Axelous, M.A.V., Tchoubar, D., and Bottero, S.Y., Langmuir, , 1989, 5, 1186.
21. Iler, R.K., The Chemistry of Silica, J. Wiley, New York, (1979).

In-Situ Pore Structure Analysis During Aging and Drying of Gels

  • Douglas M. Smith (a1), Pamela J. Davis (a1) and C. Jeffrey Brinker (a2)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed