New amino-inorganic hybrids from talc silylation and copper adsorption properties

The aminated trialkoxysilanes were immobilized on natural talc mineral surface. The obtained inorganic-organic hybrids, designated as TCx (x = 1 to 3) are related to 3-aminopropyl-, N-propylethylenediamine- and N-propyltriethylenediaminetrimethoxysilane, respectively. The number of amino groups attached to the pendant organic chains were 4.38, 2.56 and 2.03 mmol g-1 for TCx (x =1 to 3), respectively. The obtained materials maintain the original structure of the precursor talc and some changes in basal spacing were observed. The infrared spectra showed bands associated with the organic moieties ν(NH) at 3363 and 3293 cm-1, symmetric and assymmetric ν(C-H) at 2930 and 2867 cm-1 and the weak δ(Si-C) band at 1130 cm-1. The decrease in intensity of the absorption, corresponding to ν(Mg-OH) vibration was detected, whose behavior is in agreement with XRD data, that indicated a functionalization only on surface. The adsorption properties for copper cation in aqueous solutions were also observed due to the presence of amino groups of the attached organic chains covalently bonded on surface.