Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/60706
Type: Artigo de periódico
Title: Ion-imprinted polyvinylimidazole-silica hybrid copolymer for selective extraction of Pb(II): Characterization and metal adsorption kinetic and thermodynamic studies
Author: Tarley, CRT
Andrade, FN
de Santana, H
Zaia, DAM
Beijo, LA
Segatelli, MG
Abstract: The current paper presents a synthesis of a novel ion-imprinted hybrid copolymer (IIHC)[poly(1-vinylimidazole)-co-(3-(trimethoxysilyl)propyl methacrylate) and its application to selective adsorption of Pb2+ ions. The hybrid copolymer was prepared by coupling free radical addition and sol-gel processing, using tetraethoxysilane (TEOS) as cross-linker. Thermogravimetry (TG), FT-IR, X-ray diffraction, specific surface area (BET) and scanning electron microscopy (SEM) were used to characterize the copolymers. The equilibrium data obtained were fitted very well to the non-linear Langmuir-Freundlich isotherm model, as compared to other models, and the maximum adsorption uptake was found to be 7.6 mg g(-1). The thermodynamic parameters, including Gibbs free energy (Delta G degrees). enthalpy (Delta H degrees), and entropy (Delta S degrees) of the adsorption process, were found to be -16.23 kJ mol(-1), -10.37 kmol(-1) and -19.42J K-1 mol(-1), respectively. These results demonstrate that the adsorption of Pb2+ onto the hybrid copolymer takes place by a spontaneous and exothermic process with further decrease in the degree of freedom without disordering at the solid-solution interface due to the negative Delta S degrees value. Furthermore, the pseudo-first-order and pseudo-second-order models were used to describe the kinetic data. The experimental data were fitted well to the pseudo-first-order kinetics. Under competitive adsorption conditions, the ion-imprinted hybrid copolymer was 8.8, 64.9 and 16 times more selective when compared to the blank copolymer (NIC - non-imprinted copolymer) for Pb2+/Cu2+, Pb2+/Cd2+, and Pb2+/Zn2+ systems. (C) 2011 Elsevier Ltd. All rights reserved.
Subject: Lead
Ion-imprinted hybrid copolymer
Adsorption
Kinetic and thermodynamic data
Country: Holanda
Editor: Elsevier Science Bv
Rights: fechado
Identifier DOI: 10.1016/j.reactfunctpolym.2011.10.008
Date Issue: 2012
Appears in Collections:Unicamp - Artigos e Outros Documentos

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