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Cellulose acetate-Al2O3 hybrid material coated with N-Propyl-1,4-diazabicyclo [2.2.2] octane chloride: preparation, characterization and study of some metal halides adsorption from ethanol solution

Texto completo
Autor(es):
Gislene Splendore [1] ; Edilson V. Benvenutti [2] ; Yuriy V. Kholin [3] ; Yoshitaka Gushikem [4]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Universidade Estadual de Campinas. Instituto de Quimica - Brasil
[2] Universidade Federal do Rio Grande do Sul. Instituto de Química - Brasil
[3] V.N. Karazin Kharkov National University. Chemical Faculty - Ucrânia
[4] Universidade Estadual de Campinas. Instituto de Quimica - Brasil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Journal of the Brazilian Chemical Society; v. 16, n. 2, p. 147-152, 2005-04-00.
Resumo

The preparation, characterization as well as the adsorption properties of MCl n (M= Fe(III), Co(II) and Cu(II)) from ethanol solutions by the new hybrid material cellulose acetate /Al2O3 coated with N-propyl-1,4 diazabicyclo [2.2.2] octane chloride group are described. The diamine is bonded to the cellulose acetate /Al2O3 surface by Al-O-Si covalent bonds and thus, the material obtained is chemically very stable and shows high adsorption capacity in adsorbing MCl n from ethanol solutions. When the material (designated as sigma-L+Cl-) comes into contact with the metal halide solutions, the salts diffuse into the substrate-solution interface as neutral species and are fixed in the form of the anionic complexes. The latter are held near the surface due to the electrostatic interactions with the positively charged centers ~L+. The adsorption capacities of the material (t, in mmol g-1) and its affinities to the metal halides were determined by analyzing the adsorption isotherms with the help of the model of fixed polydentate centers. The constants of the adsorption equilibria (beta, in L mol-1) were used as the quantitative characteristics of affinity. For the FeCl3 adsorption equilibrium <IMG SRC="/img/revistas/jbchs/v16n2/en_a04img01.gif">the specific concentration of the sorption centers <IMG SRC="/img/revistas/jbchs/v16n2/en_a04img02.gif">is equal to 1.42 and log beta11 = 3.14. The adsorption of CoCl2 and CuCl2 (MCl2) is described in a more complicated way: <IMG SRC="/img/revistas/jbchs/v16n2/en_a04img03.gif"> The following values of parameters were obtained: <IMG SRC="/img/revistas/jbchs/v16n2/en_a04img04.gif" > or = 0.20 and 0.115; log beta21 = 4.08 and 3.3 for CoCl2 and CuCl2 respectively. (AU)

Processo FAPESP: 00/11103-5 - Materiais porosos: preparação, propriedades e aplicações
Beneficiário:Yoshitaka Gushikem
Modalidade de apoio: Auxílio à Pesquisa - Temático