Adsorption of divalent cations on the silica-gel surface modified with N-(2-aminoethyl-3-aminopropyl) groups

2019/6/8

Features of the metal—ligand interactions of some divalent cations of the first transition series with N-(2-aminoethyl-3-aminopropyl)trimethoxysilane anchored on a silica-gel surface were studied in both ethanol and acetone solution. The adsorption capacity and equilibrium constant for each metal was determined, from the solvents, through the adsorption isotherms. Co(II) and Cu(II) in both solvents and Zn(II) in acetone formed surface complexes in the ratio  Si (CH2)3, NH(CH2)2 NH2 : M (II) = 2:1, while for Ni (II) and Zn (II) in ethanol this ratio was 1:1. The enthalpies of reaction were more exothermic in acetone than in ethanol.