Patra, Amitava and Ganguli, Dibyendu (1992) Effects of PB2+-doping on alkoxide-derived silica sols and gels. Journal of Non-Crystalline Solids, 139 (2). pp. 165-171. ISSN 0022-3093

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Abstract

Five sols prepared from tetraethyl orthosilicate (TEOS) with 0 to 2 equivalent mol% PbO displayed sharp and progressive changes in the viscosity of the sols, and an increase in viscosity with time and gelling time. Activation energies of gelation (calculated from gelling times at 10, 24, 30, 40 and 50-degrees-C) showed similar sharp changes. The acceleration of gelling time with Pb2+ was found to be much more pronounced than with divalent cations Mg2+, Ca2+ and Zn2+. UV absorption edges of the gels showed significant changes with increase in dopant content, as did the corresponding optical gaps. The acceleration of gelation was considered to be caused by the linkage of Pb2+ with small polymeric clusters via = SiO- terminal groups, and the consequent aggregation of the clusters.

Item Type:	Article
Subjects:	Engineering Materials
Divisions:	Sol Gel
Depositing User:	Bidhan Chaudhuri
Date Deposited:	28 Nov 2013 08:15
Last Modified:	28 Feb 2016 18:30
URI:	http://cgcri.csircentral.net/id/eprint/2343

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