Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/97396
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 C.R.T.
Andrade F.N.
Santana H.D.
Zaia D.A.M.
Beijo L.A.
Segatelli M.G.
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 Pb 2+ 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 (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) of the adsorption process, were found to be -16.23 kJ mol -1, -10.37 kmol -1 and -19.42 J K -1 mol -1, respectively. These results demonstrate that the adsorption of Pb 2+ 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 ΔS° 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 Pb 2+/Cu 2+, Pb 2+/Cd 2+, and Pb 2+/Zn 2+ systems. © 2011 Elsevier Ltd. All rights reserved.
Editor: 
Rights: fechado
Identifier DOI: 10.1016/j.reactfunctpolym.2011.10.008
Address: http://www.scopus.com/inward/record.url?eid=2-s2.0-81355147297&partnerID=40&md5=f07f35465e47e94a46d3cac621cb5e81
Date Issue: 2012
Appears in Collections:Unicamp - Artigos e Outros Documentos

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