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|Type:||Artigo de periódico|
|Title:||Sodium alginate films modified by raw and functionalized attapulgite for use of thorium(IV) adsorption: A thermodynamic approach (Retracted article. See vol. 73, pg. 142, 2012)|
da Costa, LP
|Abstract:||Hybrid composite films were prepared by incorporating 0.2, 0.4 and 0.6 g of natural and modified attapulgite clays particles into sodium alginate films. Attapulgite sample has been chemically modified with organofunctionalization of 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane. These hybrid films were used for thorium adsorption from aqueous solutions under batch process with pH and Th(4+) concentration as variables. The effect of attapulgite incorporation in sodium alginate films has been investigated by silicon and carbon nuclei solid-state MAS/NMR, elemental analysis, CHN, textural analysis, SEM, and mechanical properties (0-30 wt% of clay samples). The reactive centers attached to the pendant chains inside the sodium alginate films can coordinate thorium(IV), by presenting and isotherm saturated at 33.70 x 10(-5) mol g(-1) of this actinide. From calorimetric determinations the quantitative thermal effects for all thorium/film surfaces gave exothermic enthalpy (Delta(int)H=-4.35 to -5.90 kJ mol(-1)), negative Gibbs free energy (Delta(int)G=-22.62 to -24.51 kJ mol(-1)), and positive entropy (Delta(int)S=61.18 to 62.36 JK(-1) mol(-1)). These thermodynamic data confirmed the energetically favorable condition of such interaction solid/liquid for all systems. (C) 2009 Published by Elsevier Ltd.|
|Editor:||Pergamon-elsevier Science Ltd|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
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