Thermal stability of amine-functionalized MCM-41 in different atmospheres

In the present work, we report on the thermal stability of NH ₂-MCM-41 hybrid material under different atmospheres (nitrogen and air). The thermal stability of this hybrid material is very important because of its common use in catalysis, adsorption, biomedical and biotechnological applications, based on mesoporous and aminopropyl functionalities. Samples were prepared by one pot co-condensation method with different loadings of 3-aminopropyltriethoxysilane (APTES). The thermal stability of hybrid samples (NH₂-MCM-41) heat treated in nitrogen and air at 30-800 C has been investigated. Samples were synthesized under basic media in the presence of cetyltrimethylammonium bromide (CTABr) as structure-directing agent, tetraethyl orthosilicate as silica source, and APTES as functionalizing agent with molar composition of 0.055 CTABr:045 SiO₂:0.054 APTES:5.32 NH ₄OH:14.99 H₂O at 50 C for 24 h at pH 12.4. The obtained hybrid materials have been characterized by thermogravimetric analysis (TG), derivative thermogravimetric analysis, differential scanning calorimetry, X-ray powder diffraction, Fourier-transform infrared spectroscopy, transmission electron microscopy, and surface area determination by the BET method. Based on TG measurements of the treated samples, it was found out that the thermal stability varied greatly in different atmospheres.