Resumen de Characterisation of the grafting of (3-aminoethyl)aminopropyltrimethoxy silane on precipitated silica
S. de Monredon
In this study, we have investigated the reaction between (3-aminoethyl)amino-propyltrimethoxysilane (AEPTS) and a precipitated silica in organic solvents. Solid-state 29Si NMR and Karl Fischer titration have been used to produce useful information on the grafted silica samples. AEPTS was chosen in order to characterise the distribution of alkoxysilanes at the silica surface. Indeed, this alkoxysilane has an ethylene diamine function that can form coloured and paramagnetic complexes with copper in 1 ∶ 1 and 2 ∶ 1 molar ratios ([Cu(AEP-Si[triple bond, length as m-dash])]2+ and [Cu(AEP-Si[triple bond, length as m-dash])2]2+). These species have been further identified and quantified by UV-visible and ESR spectroscopies, and the proximity of the alkoxysilanes at the surface was thus traced back through the detection of the 2 ∶ 1 complex [Cu(AEP-Si)2]2+.
