Pal, Rahul and Kundu, Debtosh (2009) Sol-gel synthesis of porous and dense silica microspheres. Journal of Non-Crystalline Solids, 355 (1). pp. 76-78. ISSN 0022-3093

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Abstract

An acidic silica sol (35 +/- 2 wt% equivalent SiO(2)) having a gelling time of 9-10 min has been used as an aqueous phase for obtaining a w/o emulsion in CCl(4) as Oil phase in presence of a surfactant, Tween 80. The silica sol was allowed to form gel at room temperature via polycondensation among the -Si-OH groups forming the porous silica gel microspheres. The surface area of the microspheres heated at 500 degrees, 700 degrees and 900 degrees C was found to be 227 m(2)/g, 167 m(2)/g and 81 m(2)/g indicating the gradual densification. The decreased surface area and unchanged -Si-O-Si- asymmetric stretching vibration at 1084 cm(-1) up to 700 degrees C probably indicate the formation of extensive cross-linked gel structure in the microsphere. The appearance of the -Si-O-Si- asymmetric stretching vibration at 1104 cm(-1) and the absence of porosity while heating at 1000 degrees C indicate the formation of dense silica glass microspheres. (C) 2008 Elsevier B.V. All rights reserved.

Item Type:	Article
Uncontrolled Keywords:	Sol-gels (xerogels)
Subjects:	Engineering Materials
Divisions:	Sol Gel
Depositing User:	Bidhan Chaudhuri
Date Deposited:	01 Mar 2012 07:53
Last Modified:	01 Mar 2012 07:53
URI:	http://cgcri.csircentral.net/id/eprint/1077

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