Well-Defined Mesostructured Organic−Inorganic Hybrid Materials via Atom Transfer Radical Grafting of Oligomethacrylates onto SBA-15 Pore Surfaces

Well-ordered mesoporous organic−inorganic hybrid materials based on ATRP of methacrylate monomers inside SBA-15 pores have been synthesized maintaining the mesoporosity. Initially SBA-15 materials were funtionalised with the ATRP initiator by reaction of surface hydroxyl groups with (3-aminopropyl)-triethoxysilane (APTES) and 2-bromo-2-methylpropionyl bromide (BMPB); thus growth of oligomethacrylates occurred directly from the mesoporous walls. Two methacrylate monomers (MMA and GMA) and different monomer/initiator molar ratios (5/1 − 25/1) were tested. The characterization of the hybrid materials included N 2 adsorption−desorption porosimetry, X-ray diffraction, 29 Si MAS NMR, FT-IR spectroscopy, TEM and TG analysis. The results show that mesostructured hybrid materials with grafted oligomethacrylates maintain good porosity (∼ 0.4 cm 3 /g) and BET surface area (∼ 300 m 2 /g) with potential for use as catalyst components in chemical processes. The grafting of GMA-based oligomers is particularly important because the epoxide functionality allows further facile and versatile chemical modification, for example to introduce particular ligand structures and thence specific metal complexes.