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Gelation Point In Borosilicate Sols From Rheological Experiments

  • Srinivas Surapanani (a1), Michael E. Mullins (a1), Faith Morrison (a1) and Bahne C. Cornilsen (a2)


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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1 Sakka, S. and Kozuka, H. J., Non Crystalline Solids, 100, 142153 (1988)
2 Seki, T., and Ichimura, K., Macromolecules, 20, 29572958 (1987).
3 Song, K.C., and Chung, I.J., J. Non-Crystalline Solids, 107, 193198 (1989).
4 Sacks, M.D., and Kozuka, H., J. Non-Crystalline Solids,100,142153 (1988).
5 Winter, H.H., and Chambón, F.J., Rheology, 30(2),367382(1976).
6 Chambón, F. and Winter, H.H., Journal of Rheology 31 (8), 683697(1987).
7 Chambón, F., Petrovic, Z.S., MacKnight, W.J., and Winter, H.H., Macromolecules., 19 2146(1986).
8 Winter, H.H., Polymer Engineering and Science 27 (22), 16981702 (1987).
9 Winter, H.H., Morganelli, P., and Chambón, F., Macromolecules, 21, 532535 (1987).
10 Khan, S.A., Rabinovich, E.M., Prud'homme, R.K., Sammon, M.J., Kopylov, N.J. in Better Ceramics through Chemistry III, edited by Brinker, C.J., Clark, D.E., Ulrich, D.R., (Mater. Res.Soc.Proc. 121 Pittsburg, PA 1990) pp. 7380.
11 Khan, S.A., Rabinovich, E.M., Prud'homme, R.K., Sammon, M.J., Kopylov, N.J., Mat.Res. Soc.,Proc.,121,73(1988).
12 Sacks, M.D. and Sheu, R.S., Science of Ceramic Chemical Processing, eds Hench, L.L. and Ulrich, D.R. (Wiley, New York, 1986) pp 100107.
13 Sacks, M.D. and Sheu, R.S., J. Non. Cryst. Sol.92 383396, (1987).
14 Keesman, M.J., Offermans, P.H.G. and Honig, E.P, Materials Letters Volume 5, number 4 (Elseviaer Science Publishers North-Holland Physics Publishing Division, 1987) p. 140.
15 Brinker, C.J. and Scheren, G.W. Sol-Gel Science. The Physics and Chemistry of Sol-Gel Pro-cessing. (Academic Press Inc. 1990).
16 Mackosco, C.W, MeCartney, M.L. and Scriven, L.E., Mat.Res.Soc.Symp.Proc, 180, 555 (1990).
17 Yoldas, B.E., Journal of Non-Crystalline Solids, 63,145154 (1984).
18 Tung, CH-YM, Dynes, PJ J. Appl. Polym. Sci. 27,569 (1982).
19 Muthukumar, M., J. Chem.Phys., 83, 3161 (1985).
20 Stauffer, D., Coniglio, A. and Adam, M., Adv. Polym. Sci., 44, 74 (1982).
21 Flory, P.J., Principles of Polymer Chemistry. (Cornell, University Press, Ithaca, NY, 1953)
22 Zimm, B. and Stockmayer, W.H., J.Chem.Phys., 17 1301 (1949)


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