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Microstructural Studies of Transparent Silica Gels and Aerogels

  • Param H. Tewari (a1), Arlon J. Hunt (a1), K. D. Lofftus (a1) and J. G. Lieber (a1)

Abstract

Transmission electron microscopy, spectroscopy, light scattering and surface area measurements have been used to characterize the microstructural details of transparent silica aerogels. Light scattering intensity measurements have also been used to differentiate acid and base catalyzed hydrolysis and condensation reaction kinetics of Si(OC2H5)4. A plot of logarithm of the light scattering intensity vs. logarithm of time diring gelation gives distinctly different slopes for acid and base catalyzed systems (6 for acid and 2 for base). These slopes for the two systems can be explained on the basis of the point of zero charge of silica and the resulting interactions of the uncharged and charged particles in the systems.

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Microstructural Studies of Transparent Silica Gels and Aerogels

  • Param H. Tewari (a1), Arlon J. Hunt (a1), K. D. Lofftus (a1) and J. G. Lieber (a1)

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