Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/63053
Type: Artigo de periódico
Title: Chemisorption and thermodynamic data of the interaction between a chelate free acidic center with basic groups attached to grafted silicas
Author: Arakaki, LNH
de Sousa, AN
Espinola, JGP
Oliveira, SF
Airoldi, C
Abstract: The molecule 2-aminoethanethiol was added to the grafted silylant agent [(3-chlorosilylpropyl)trimethoxysilane] (cpts) onto silica gel(dropSil-Cl), obtaining a surface (dropSil-SNH2) and giving 0.70 mmol g(-1) of nitrogen; the surface of silica was modified with [(3-mercaptosilylpropyl)trimethoxysilane] (mpts) with surface (dropSil-SH), giving 0.78 mmol g(-1) of sulphur. Both matrices, (dropSil-SNH2) and (dropSil-SH), adsorb copper and cobalt acetylacetonates from ethanolic solution. Adsorption, using a batch-wise process, showed that copper chelate was the most adsorbed. The interactions between the basic centers attached to organic chains of these modified silicas with the cations in the chelates Me(acac)(2) [M = Cu and Co] were followed through calorimetric titrations. Exothermic enthalpic results were obtained for the dropSil-SNH2 matrix. The spontaneity of these systems was reflected in negative free Gibbs energy and positive from entropic values. (C) 2002 Elsevier Science (USA).
Subject: silica gel
beta-diketonates
chemisorption
calorimetry
thermodynamic data
Country: EUA
Editor: Academic Press Inc Elsevier Science
Rights: fechado
Identifier DOI: 10.1006/jcis.2002.8290
Date Issue: 2002
Appears in Collections:Unicamp - Artigos e Outros Documentos

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