Hostname: page-component-76fb5796d-r6qrq Total loading time: 0 Render date: 2024-04-26T16:30:02.539Z Has data issue: false hasContentIssue false
  • English
  • Français

Gelation Point In Borosilicate Sols From Rheological Experiments

Published online by Cambridge University Press:  21 February 2011

Srinivas Surapanani ,
Michael E. Mullins ,
Faith Morrison  and
Bahne C. Cornilsen
Srinivas Surapanani
Affiliation:
Department of Chemical Engineering, Michigan Technological University, Houghton,MI 49931
Michael E. Mullins
Affiliation:
Department of Chemical Engineering, Michigan Technological University, Houghton,MI 49931
Faith Morrison
Affiliation:
Department of Chemical Engineering, Michigan Technological University, Houghton,MI 49931
Bahne C. Cornilsen
Affiliation:
Department of Chemistry, Michigan Technological University, Houghton, MI 49931
Get access

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.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 346: Symposium N – Better Ceramics Through Chemistry VI , 1994 , 785
Copyright
Copyright © Materials Research Society 1998

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.)

References

REFERENCES

1 Sakka, S. and Kozuka, H. J., Non Crystalline Solids, 100, 142–153 (1988)Google Scholar
2 Seki, T., and Ichimura, K., Macromolecules, 20, 2957–2958 (1987).Google Scholar
3 Song, K.C., and Chung, I.J., J. Non-Crystalline Solids, 107, 193–198 (1989).Google Scholar
4 Sacks, M.D., and Kozuka, H., J. Non-Crystalline Solids,100,142–153 (1988).Google Scholar
5 Winter, H.H., and Chambón, F.J., Rheology, 30(2),367–382(1976).Google Scholar
6 Chambón, F. and Winter, H.H., Journal of Rheology 31 (8), 683–697(1987).Google Scholar
7 Chambón, F., Petrovic, Z.S., MacKnight, W.J., and Winter, H.H., Macromolecules., 19 2146(1986).Google Scholar
8 Winter, H.H., Polymer Engineering and Science 27 (22), 1698–1702 (1987).Google Scholar
9 Winter, H.H., Morganelli, P., and Chambón, F., Macromolecules, 21, 532–535 (1987).Google Scholar
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. 73–80.Google Scholar
11 Khan, S.A., Rabinovich, E.M., Prud'homme, R.K., Sammon, M.J., Kopylov, N.J., Mat.Res. Soc.,Proc.,121,73(1988).Google Scholar
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 100–107.Google Scholar
13 Sacks, M.D. and Sheu, R.S., J. Non. Cryst. Sol. ‘92 383–396, (1987).Google Scholar
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.Google Scholar
15 Brinker, C.J. and Scheren, G.W. Sol-Gel Science. The Physics and Chemistry of Sol-Gel Pro-cessing. (Academic Press Inc. 1990).Google Scholar
16 Mackosco, C.W, MeCartney, M.L. and Scriven, L.E., Mat.Res.Soc.Symp.Proc, 180, 555 (1990).Google Scholar
17 Yoldas, B.E., Journal of Non-Crystalline Solids, 63,145–154 (1984).Google Scholar
18 Tung, CH-YM, Dynes, PJ J. Appl. Polym. Sci. 27,569 (1982).Google Scholar
19 Muthukumar, M., J. Chem.Phys., 83, 3161 (1985).Google Scholar
20 Stauffer, D., Coniglio, A. and Adam, M., Adv. Polym. Sci., 44, 74 (1982).Google Scholar
21 Flory, P.J., Principles of Polymer Chemistry. (Cornell, University Press, Ithaca, NY, 1953)Google Scholar
22 Zimm, B. and Stockmayer, W.H., J.Chem.Phys., 17 1301 (1949)Google Scholar