Patra, Amitava and Kundu, Debtosh and Ganguli, Dibyendu (1997) Spectroscopic study of cerium-doped silica gel monoliths and their densified derivatives. Journal of Sol-Gel Science and Technology, 9 (1). pp. 65-69. ISSN 0928-0707

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Abstract

Cerium is exploited as a probe cation for elucidating the structure of an alkoxide-derived silica gel and its progressive evolution to a glass network as a function of heat-treatment up to 1000 degrees C. At intermediate temperatures, the host structure exhibits inhomogeneity due to insufficient formation of siloxane bonds, which is reflected by at least two different sites and co-ordination spheres (termed `'high'' and `'low'' water ligation) for cerium. This is proved by the response of the gels heated up to 700 degrees C to rehydration. Further formation of Si-O-Si network (900 degrees C) leads to the destruction of the `'high water'' sites of cerium and progression towards a glassy structure. It is, however, only after heat-treatment at 1000 degrees C that a dense silica glass network, not responding to rehydration, is finally obtained with cerium ions embedded in it.

Item Type:	Article
Uncontrolled Keywords:	sol-gel; cerium; silica gel; rehydration
Subjects:	Microstructure and Characterization Engineering Materials
Divisions:	Sol Gel
Depositing User:	Bidhan Chaudhuri
Date Deposited:	19 Jul 2012 07:19
Last Modified:	28 Sep 2015 06:32
URI:	http://cgcri.csircentral.net/id/eprint/1627

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