Synthesis of amino-functionalized MCM-41 via direct co-condensation and post-synthesis grafting methods using mono-, di- and tri-amino-organoalkoxysilanesElectronic supplementary information (ESI) available: XRD patterns of (A) x-dNN-MCM-41 and (B) x-dNNN-MCM-41 after the extraction of the surfactant, 29Si MAS NMR spectra of MCM-41 samples prepared by (A) direct co-condensation and (B) post-synthesis grafting methods. See http://www.rsc.org/suppdata/jm/b3/b310576h/