Functionalization with amine-containing organosilane of mesoporous silica MCM-41 and MCM-48 obtained at room temperature

Functionalized ordered MCM-41 and MCM-48 materials have been obtained by a post-grafting method using 3-aminopropyltrimethoxysilane (APS) as modifying agent. The dependence of APS concentration, and reaction time on average pore size, grafted APS content, pore volume, superficial area, and morphology was studied. The modified silicas were characterized by powder X-ray diffraction (XRD), infrared spectroscopy (FT-IR), transmission electron microscope (TEM) and nitrogen adsorption-desorption experiments. MCM-41 appeared to be more prone to pore blockage than MCM-48 in the grafting procedure. According to the TEM results, no morphological changes were observed in the modified MCM-41 and MCM-48 silicas by comparing with bare silicas. These amine-grafted silicas could have potential application to be used as adsorbents of CO2 in the natural gas sweetening process or as fillers in the preparation of mixed matrix membranes.