Gelation Point In Borosilicate Sols From Rheological Experiments

Abstract

Dynamic oscillatory experiments are used to monitor the gelation of the borosilicate systems prepared through the sol-gel process from metal alkoxides. The rheological experiments show that tan δ = G”/G’ is independent of frequency at the gel point in agreement with the results of others on organic gelling systems. The dynamic moduli at the gel point followed power-law behavior with respect to frequency. The power-law exponent is found to be ~0.70. The apparent fractal dimension, dp, of the network cluster at the gel point is determined. The dF values for the samples ranged from 2.5 to 3.8 depending on the final structure of the evolved products at the gel point. The large values (dF > 3) exclude a simple geometric interpretation of the results. The effect of processing parameters, such as composition of reactants and temperature, on the resulting microstructures near the gel point is discussed.

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References

  1. 1

    S. Sakka and H. Kozuka J., Non Crystalline Solids, 100, 142–153 (1988)

    CAS  Article  Google Scholar 

  2. 2

    T. Seki, and K. Ichimura, Macromolecules, 20, 2957–2958 (1987).

    Article  Google Scholar 

  3. 3

    K.C. Song, and I.J. Chung, J. Non-Crystalline Solids, 107, 193–198 (1989).

    CAS  Article  Google Scholar 

  4. 4

    M.D. Sacks, and H. Kozuka, J. Non-Crystalline Solids, 100, 142–153 (1988).

    Article  Google Scholar 

  5. 5

    H.H. Winter, and F.J. Chambón, Rheology, 30(2), 367–382(1976).

    Article  Google Scholar 

  6. 6

    F. Chambón and H.H. Winter, Journal of Rheology 31 (8), 683–697(1987).

    Article  Google Scholar 

  7. 7

    F. Chambón, Z.S. Petrovic, W.J. MacKnight, and H.H. Winter, Macromolecules., 19 2146(1986).

    Article  Google Scholar 

  8. 8

    H.H. Winter, Polymer Engineering and Science 27 (22), 1698–1702 (1987).

    CAS  Article  Google Scholar 

  9. 9

    H.H. Winter, P. Morganelli, and F. Chambón, Macromolecules, 21, 532–535 (1987).

    Article  Google Scholar 

  10. 10

    S.A. Khan, E.M. Rabinovich, R.K. Prud’homme, M.J. Sammon, N.J. Kopylov in Better Ceramics through Chemistry III, edited by C.J. Brinker, D.E. Clark, D.R. Ulrich, (Mater. Res.Soc.Proc. 121 Pittsburg, PA 1990) pp.73–80.

  11. 11

    S.A. Khan, E.M. Rabinovich, R.K. Prud’homme, M.J. Sammon, N.J. Kopylov, Mat.Res. Soc., Proc., 121, 73(1988).

    CAS  Article  Google Scholar 

  12. 12

    M.D. Sacks and R.S. Sheu, Science of Ceramic Chemical Processing, eds L.L. Hench and D.R. Ulrich (Wiley, New York,1986)100–107.

  13. 13

    M.D. Sacks and R.S. Sheu, J. Non. Cryst. Sol. 92 383–396, (1987).

    CAS  Article  Google Scholar 

  14. 14

    M.J. Keesman, P.H.G. Offermans and E.P Honig, Materials Letters Volume 5, number 4 (Elseviaer Science Publishers North-Holland Physics Publishing Division,1987) p. 140.

    Google Scholar 

  15. 15

    C.J. Brinker and G.W. Scheren Sol-Gel Science. The Physics and Chemistry of Sol-Gel Pro-cessing. (Academic Press Inc. 1990).

    Google Scholar 

  16. 16

    C.W Mackosco, M.L. MeCartney and L.E. Scriven, Mat.Res.Soc.Symp.Proc, 180, 555 (1990).

    Article  Google Scholar 

  17. 17

    B.E. Yoldas, Journal of Non-Crystalline Solids, 63, 145–154 (1984).

    CAS  Article  Google Scholar 

  18. 18

    CH-YM Tung, PJ Dynes J. Appl. Polym. Sci. 27, 569 (1982).

    CAS  Article  Google Scholar 

  19. 19

    M. Muthukumar, J. Chem.Phys., 83, 3161 (1985).

    CAS  Article  Google Scholar 

  20. 20

    D. Stauffer, A. Coniglio and M. Adam, Adv. Polym. Sci., 44, 74 (1982).

    Google Scholar 

  21. 21

    P.J. Flory, Principles of Polymer Chemistry. (Cornell, University Press, Ithaca, NY, 1953)

    Google Scholar 

  22. 22

    B. Zimm and W.H. Stockmayer, J.Chem.Phys., 17 1301 (1949)

    CAS  Article  Google Scholar 

Download references

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Correspondence to Srinivas Surapanani.

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Surapanani, S., Mullins, M.E., Morrison, F. et al. Gelation Point In Borosilicate Sols From Rheological Experiments. MRS Online Proceedings Library 346, 785–795 (1994). https://doi.org/10.1557/PROC-346-785

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