Effect of Polyethylenimine Loading on the Physicochemical Properties of Amine-Functionalized Si-MCM-41

Si-MCM-41 with highly ordered uniform mesopores was synthesized hydrothermally at 100 oC. The calcined Si-MCM-41 was then functionalized with 10-50% (w/w) polyethylenimine (PEI) via impregnation method. The physicochemical properties of these samples were characterized using FTIR, TGA, FESEM, TEM and CHNS analysis. Results show that the Si-MCM-41 was successfully functionalized with PEI. FTIR analysis shows that all the characteristic peaks of Si-MCM-41 i.e. 794, 1080 & 1240 cm-1 are still present in PEI-functionalized Si-MCM-41, which means that the mesoporous frame work is preserved. TGA analysis shows that the PEI-functionalized Si-MCM-41 is thermally stable up to 200-250 oC. FESEM images show that as the PEI weight percent increases to 50wt%, the PEI-functionalized Si-MCM-41 became agglomerated, which indicates that the PEI is distributed into the pores and on the external surface of the Si-MCM-41. TEM results also show that the hexagonal pore structure remains intact and the pores are filled with PEI. CHNS analysis confirms the presence of nitrogen in the PEI-functionalized Si-MCM-41.