Artículos de revistas
Thermodynamics of the nickel and cobalt removal from aqueous solution by layered crystalline organofunctionalized barium phosphate
Registro en:
Journal Of Chemical Thermodynamics. Academic Press Ltd Elsevier Science Ltd, v. 41, n. 1, n. 21, n. 25, 2009.
0021-9614
WOS:000262195600004
10.1016/j.jct.2008.08.005
Autor
Lazarin, AM
Airoldi, C
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The available hydroxyl groups inside the lamellar cavity of barium phosphate (BaP) reacted with the silylating agents (RO)(3)Si(CH(2))(3)L(x) (L(1)= NH(2), L(2) = NH(CH(2))(2)NH(2), and L(3) = NH(CH(2))(2) NH(CH(2))(2)NH(2)), to yield organofunctionalized BaPSiL(1), BaPSiL(2) and BaPSiL(3) nanomaterials. The amounts of organofunctional groups covalently attached to the inorganic layer were (1.24, 1.46, and 1.23) mmol . g(-1), respectively. The basic nitrogen atoms attached to the distinct pendant organic chains adsorb divalent nickel and cobalt from aqueous solutions, as represented by well-established isotherms. The energetic effects caused by metallic cation interactions were determined through calorimetric titration at the solid/liquid interface and gave a net thermal effect that enabled enthalpy and equilibrium constant calculations. Complete thermodynamic results composed of exothermic enthalpy, negative free Gibbs energy and positive entropy result in a set of favourable cation/basic centre interactions, to indicate that these nanomaterials could be useful tools to eliminate undesirable cations from aqueous systems. (C) 2008 Elsevier Ltd. All rights reserved. 41 1 21 25 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)