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Structural Development In Silica Systems

Published online by Cambridge University Press:  21 February 2011

W.H. Dokter
Affiliation:
Schuit Institute of Catalysis, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
T.P.M. Beden
Affiliation:
Schuit Institute of Catalysis, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
H.F. van Garderen
Affiliation:
Schuit Institute of Catalysis, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
R.A. van Santen
Affiliation:
Schuit Institute of Catalysis, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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Abstract

Results obtained with small angle neutron and X-ray scattering will be presented of systems with various silica concentrations. Silica gels with low silica concentration exhibit uniform mass fractal behaviour and after prolonged aging, dual mass fractal behaviour. A zeolite (silicalite) synthesis precursor gel with a high silica concentration was also investigated and was found to exhibit surface fractal behaviour. A model is presented, explaining the occurrence of dual fractality after prolonged aging. The change-over from mass fractal behaviour to surface fractal behaviour is explained, supported by scattering spectra calculated from simulated aggregate structures.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

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