caa a22 4500 463193253 CHVBK 20180406164915.0 cr unu---uuuuu 170326e20070301xx s 000 0 eng 10.1007/s10973-006-7756-2 doi (NATIONALLICENCE)springer-10.1007/s10973-006-7756-2 Interactionof divalent cations Zn, Cd and Hg on surface of silica gelwith aminoethanethiolas evaluated by calorimetric titration [Elektronische Daten] [Vera da S. Augusto Filha, Oberto da Silva, J. da Costa, Albaneide Wanderley, Maria da Fonseca, Luiza Arakaki] Calorimetric titration was applied to study the interaction of zinc, cadmium and mercury on surface of silica gel modified with 2-aminoethanethiol, using 3-chloropropyltrimetoxysilane as precursor silylating agent. The anchored Sil-SNH2 surface gave 0.70 mmol g-1 of molecules covalently bonded per gram of silica. This surface displayed a chelating moiety containing sulfur and nitrogen basic centers, which are potentially capable of extracting cations from aqueous solutions, such as MCl2 (M=Zn, Cd, Hg). This process of extraction was carried out by the batch method when similar chemisorption isotherms were observed for all cations. The data were adjusted to modified Langmuir equation. The sequence of the maximum retention capacity was Hg>Cd>Zn. The processes of cation interactions showed exothermic enthalpies. The calculated ΔG values are in agreement with the spontaneity of the proposed reactions and conformed to the values found by using Langmuir model applied to these systems. The endothermic entropic values, as expected, indicated that the reactions are favorable. Springer-Verlag, 2007 2-aminoethanethiol nationallicence calorimetry nationallicence divalent metal of group 12 nationallicence silica gel nationallicence thermochemical data nationallicence da S. Augusto Filha Vera Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut da Silva Oberto Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut da Costa J. Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut Wanderley Albaneide Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut da Fonseca Maria Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut Arakaki Luiza Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut Journal of Thermal Analysis and Calorimetry Kluwer Academic Publishers 87/3(2007-03-01), 621-625 1388-6150 87:3<621 2007 87 10973 https://doi.org/10.1007/s10973-006-7756-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10973-006-7756-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- da S. Augusto Filha Vera Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut NATIONALLICENCE 700 1- da Silva Oberto Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut NATIONALLICENCE 700 1- da Costa J. Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut NATIONALLICENCE 700 1- Wanderley Albaneide Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut NATIONALLICENCE 700 1- da Fonseca Maria Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut NATIONALLICENCE 700 1- Arakaki Luiza Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Paraíba, Brazil aut NATIONALLICENCE 773 0- Journal of Thermal Analysis and Calorimetry Kluwer Academic Publishers 87/3(2007-03-01), 621-625 1388-6150 87:3<621 2007 87 10973 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer