Journal of Sol-Gel Science and Technology

, Volume 3, Issue 3, pp 169–188 | Cite as

In situ observation of phase separation processes in gelling alkoxy-derived silica system by light scattering method

  • Hironori Kaji
  • Kazuki Nakanishi
  • Naohiro Soga
  • Tadashi Inoue
  • Norio Nemoto
Article

Abstract

The investigation of phase separation processes induced by polymerization reactions of tetramethoxysilane (TMOS) was attempted by a time-resolved light scattering method for TMOS-formamide-water system under the acid-catalyzed condition. Since the early stage of the phase separation exhibits very fast kinetics and weak scattering intensity, the experimental set-up was designed so as to reduce the experimental error and to obtain higher time resolution by using a laser beam expander. For the gels whose morphologies are ‘interconnected structure’ and ‘aggregates of particles,’ it was experimentally found that the wavelength of the concentration fluctuation in the early stage of phase separation was time-independent and its amplitude grew exponentially with time. This suggests that these samples phase-separate by spinodal decomposition mechanism. In the later stages of phase separation, the coarsening process and the following structure-freezing process by gel-network formation were observed.

Keywords

porous silica gel light scattering phase separation spinodal decomposition Cahn's theory 

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References

  1. 1.
    M. Yamane, in Sol-Gel Technology for Thin Films, Fibers, Preforms, Electronics and Specialty Shapes, ed. L.C. Klein (Noyes, Park Ridge, New Jersey, 1988), p. 200.Google Scholar
  2. 2.
    L.L. Hench and G. Orcel, in Better Ceramics Through Chemistry II, eds. C.J. Brinker, D.E. Clark and D.R. Ulrich, vol. 73 (MRS, Pittsburgh, 1986), p. 35.Google Scholar
  3. 3.
    M. Toki, S. Miyashita, T. Takeuchi, S. Kanbe, and A. Kochi, J. Non-Cryst. Solids, 100 (1988) 479.Google Scholar
  4. 4.
    H. Dislich, in Sol-Gel Technology for Thin Films, Fibers, Preforms, Electronics and Specialty Shapes, ed. L.C. Klein (Noyes, Park Ridge, New Jersey, 1988), p. 50.Google Scholar
  5. 5.
    S. Sakka and K. Kamiya, J. Non-Cryst. Solids, 42 (1980) 403.Google Scholar
  6. 6.
    S. Sakka, in Sol-Gel Technology for Thin Films, Fibers, Preforms, Electronics and Specialty Shapes, ed. L.C. Klein (Noyes, Park Ridge, New Jersey, 1988), p. 140.Google Scholar
  7. 7.
    E. Matijević, in Ultrastructure Processing of Ceramics, Glasses, and Composites, eds. L.L. Hench and D.R. Ulrich (Wiley, New York, 1984), p. 334.Google Scholar
  8. 8.
    W. Stöber, A. Fink, and E. Bohn, J. Colloid Interf. Sci., 26 (1968) 62.Google Scholar
  9. 9.
    A.K. Helden, J.W. van Jansen, and A. Vrij, J. Colloid Interf. Sci., 81 (1981) 354.Google Scholar
  10. 10.
    R.D. Shoup, in Colloid and Interface Science, III (Academic Press, New York, 1976), p. 63.Google Scholar
  11. 11.
    For the dispersed system, detailed but not in situ studies for the formation of monodispersed particles according to Stöber process [8] are carried out by Bogush et al. [12, 13].Google Scholar
  12. 12.
    G.H. Bogush and C.F. Zukoski IV, in Ultrastructure Processing of Advanced Ceramics, eds. J.D. Mackenzie and D.R. Ulrich (Wiley, New York, 1988), p. 477.Google Scholar
  13. 13.
    G.H. Bogush, G.L. Dickstein, P. Lee, and C.F. Zukoski IV, in Better Ceramics Through Chemistry III, eds. C.J. Brinker, D.E. Clark and D.R. Ulrich (North-Holland, New York, 1988).Google Scholar
  14. 14.
    H. Kaji, K. Nakanishi, and N. Soga, submitted to J. Non-Cryst. Solids.Google Scholar
  15. 15.
    P. Li, C. Ohtsuki, T. Kokubo, K. Nakanishi, N. Soga, T. Nakamura, and T. Yamamuro, J. Amer. Ceram. Soc., 75 (1992) 2094.Google Scholar
  16. 16.
    N. Tanaka, N. Ishizuka, K. Hosoya, K. Kimata, H. Minakuchi, K. Nakanishi, and N. Soga, submitted to Anal. Chem.Google Scholar
  17. 17.
    H. Kaji, K. Nakanishi, and N. Soga, J. Sol-Gel Sci. and Technol., 1 (1993) 35.Google Scholar
  18. 18.
    F.S. Bates and P. Wiltzius, J. Chem. Phys., 91 (1989) 3258.Google Scholar
  19. 19.
    R.S. Stein and J.J. Keane, J. Polym. Sci., 17 (1955) 21.Google Scholar
  20. 20.
    T. Hashimoto, M. Itakura, and H. Hasegawa, J. Chem. Phys., 85 (1986) 6118.Google Scholar
  21. 21.
    Y.C. Chou and W.I. Goldberg, Phys. Rev. A, 20 (1979) 2105.Google Scholar
  22. 22.
    Laser Speckle and Related Phenomena, ed. J.C. Dainty, Topics in Applied Physics, vol. 9 (Springer-Verlag, Berlin, 1984).Google Scholar
  23. 23.
    Y.C. Chou and W.I. Goldberg, Phys. Rev. A, 23 (1981) 858.Google Scholar
  24. 24.
    H. Kaji, K. Nakanishi, and N. Soga, submitted to J. Non-Cryst. Solids.Google Scholar
  25. 25.
    R.A. Assink and B.D. Kay, J. Non-Cryst. Solids, 99 (1988) 359.Google Scholar
  26. 26.
    H. Kaji, K. Nakanishi, and N. Soga, in preparation.Google Scholar
  27. 27.
    T. Hashimoto, K. Sasaki, and H. Kawai, Macromolecules, 17 (1984) 2812.Google Scholar
  28. 28.
    R.L. Scott, J. Chem. Phys., 17 (1949) 268.Google Scholar
  29. 29.
    D. Patterson, Polym. Eng. and Sci., 22 (1982) 64.Google Scholar
  30. 30.
    A. Onuki and T. Hashimoto, Macromolecules, 22 (1989) 879.Google Scholar
  31. 31.
    T. Dobashi, M. Nakata, and M. Kaneko, J. Chem. Phys., 72 (1980) 6693.Google Scholar
  32. 32.
    P.J. Flory, Principles of Polymer Chemistry (Cornell University, Ithaca, New York, 1971).Google Scholar
  33. 33.
    P.-G. de Gennes, Scaling Concept in Polymer Physics (Cornell University Press, Ithaca, New York, 1979), Chapter 5.Google Scholar
  34. 34.
    J.W. Cahn, J. Chem. Phys., 42 (1965) 93.Google Scholar
  35. 35.
    S. Katano and M. Iizumi, Phys. Rev. Lett., 52 (1984) 835.Google Scholar
  36. 36.
    S. Komura, K. Osamura, H. Fujii, and T. Takeda, Phys. Rev. B, 31 (1985) 1278.Google Scholar
  37. 37.
    T. Hashimoto, M. Itakura, and N. Shimidzu, J. Chem. Phys., 85 (1986) 6773.Google Scholar
  38. 38.
    K. Binder and D. Stauffer, Phys. Rev. Lett., 33 (1974) 1006.Google Scholar
  39. 39.
    I.M. Lifshitz and V.V. Slyozov, J. Phys. Chem. Solids, 19 (1961) 35.Google Scholar
  40. 40.
    E.D. Siggia, Phys. Rev. A, 20 (1979) 595.Google Scholar
  41. 41.
    H. Hasegawa, T. Shiwaku, A. Nakai, and T. Hashimoto, in Dynamics of Ordering Processes in Condensed Matter, eds. S. Komura and H. Furukawa (Prenum Press, New York, 1988).Google Scholar
  42. 42.
    T. Hashimoto, M. Takenaka, and T. Izumitani, J. Chem. Phys., 97 (1992) 679.Google Scholar
  43. 43.
    K. Yamanaka and T. Inoue, Polymer, 30 (1989) 662.Google Scholar
  44. 44.
    K. Yamanaka, Y. Takagi, and T. Inoue, Polymer, 30 (1989) 1839.Google Scholar
  45. 45.
    K. Yamanaka and T. Inoue, J. Mater. Sci., 25 (1990) 241.Google Scholar
  46. 46.
    T.M. Rogers and R.C. Desai, Phys. Rev. B, 39 (1989) 11956.Google Scholar

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Hironori Kaji
    • 1
  • Kazuki Nakanishi
    • 2
  • Naohiro Soga
    • 2
  • Tadashi Inoue
    • 3
  • Norio Nemoto
    • 3
  1. 1.Department of Industrial Chemistry, Faculty of EngineeringKyoto UniversityKyotoJapan
  2. 2.Division of Material Chemistry, Faculty of EngineeringKyoto UniversityKyotoJapan
  3. 3.Institute for Chemical ResearchKyoto UniversityKyotoJapan

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