Chemisorption of Cu(II) chloride and nitrate in aqueous and non-aqueous solutions on matrix containing ethylenimine anchored on thiol modified silica gel surface

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2002-04, Vol.203 (1), p.129-136
• Main Authors: Arakaki, Luiza N.H, Espı́nola, José G.P, de Oliveira, Severino F, de Freitas, José M.P, Gouveia, Antonio G, Airoldi, Claudio
• Format: Article
• Language: English
• Subjects: Adsorption; Copper; Polarity index; Selectivity factor; Silica gel; Solvents
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/S0927-7757(01)01098-6

Matrix of silica gel organofunctionalized with thiol-ethylenimine group containing 2.60 mmol of nitrogen per gram of silica, caused extraction of CuX 2 (X=Cl − and NO 3 −) from aqueous and non-aqueous solvents like ethanol, methyl ethyl ketone and acetonitrile at 298±1 K. Extraction was performed by the batchwise process whose maximum adsorption obtained showed the decreasing sequence methyl ethyl ketone>ethanol>acetonitrile>water for both salts. Cu(II) cation in all solvents was more adsorbed under nitrate form and the calculated selectivity ( Γ n ) of the matrix related to Cu(II) was more than twice larger in the chloride form. The stoichiometry of the copper complex formed on the surface of the silica matrix was 1:1 in nitrate counteranion, in all solvents we used. Thus, with respect to chloride counteranion the stoichiometry, metal:ligand, obtained was 1:1 in the solvents methyl ethyl ketone and ethanol, and 1:2 in acetonitrile and water.