Phase separation kinetics in silica sol-gel system containing polyethylene oxide. I. Initial stage
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Domain formation kinetics in gelling alkoxy-derived silica solutions containing polyethylene oxide (PEO) has been investigated. The time-resolved light scattering measurement was performed for the polymerizing solutions which underwent phase separation in the length scale of micrometer. Domain formation processes which resulted in various sizes of inter-connected morphology were examined, focusing mainly on the initial stage. For all the samples, the scattering intensity grew exponentially with time forming a single peak at a fixed wave-number in the first few tens seconds, which is the characteristic of the linearized regime of the spinodal decomposition. An analysis based on the linearized theory proposed by Cahn gave a reasonable description of the kinetic parameter of phase separation induced in various stages of the sol-gel transition.
Keywordssilica poly(ethylene oxide) light scattering spinodal decomposition initial stage
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- 1.Nakanishi, K. and Soga, N., J. Am. Ceram. Soc., 74, 2518–30 (1991).Google Scholar
- 2.Nakanishi, K. and Soga, N., J. Non-Cryst. Solids, 139, 1–13 (1992).Google Scholar
- 3.Nakanishi, K. and Soga, N., in Chemical Processing of Advanced Materials, eds. L.L., Hench, and West, J.K., John Wiley & Sons Inc., New York, 1992. Chap. 3Google Scholar
- 4.Nakanishi, K., Yamasaki, Y., Kaji, H., and Soga, N., Proceedings of 2nd Izumi Forum (Osaka), Ed. S. Sakka, to be Published.Google Scholar
- 5.Hashimoto, T., Kumaki, J., and Kawai, H., Macromolecules, 16, 641–648 (1983).Google Scholar
- 6.Nakanishi, K., Komura, H., Takahashi, R., and Soga, N., submitted to J. Sol-Gel Sci. Tech.Google Scholar
- 7.Nakanishi, K., Yamasaki, Y., Kaji, H., Soga, N., Inoue, T., and Nemoto, N., in preparation.Google Scholar
- 8.Cahn, J.W., J. Chem. Phys., 42, 93–99 (1965).Google Scholar
- 9.For example, see; Sasaki, K. and Hashimoto, T., Macromolecules, 17, 2818–2815 (1984); Lee, H.-S., Kyu, T., Gadkari, A., Kennedy, J.P., Macromolecules, 24, 4852–4856 (1991).Google Scholar
- 10.Langer, J.S., Bar-on, M., and Miller, H.D., Phys. Rev. A, 11(4), 1417–1429 (1975).Google Scholar