Abstract: A sample of SBA-15 mesoporous silicate was synthesized and characterized by XRD and N₂ adsorption. It is confirmed from N₂ adsorption and ¹³C, ²⁹Si NMR techniques that the surface of SBA-15 was chemically modified with 3-aminopropyltrimethoxylsilane. According to integration of the curve of the ²⁹Si MAS(Magic Angle Spinning) NMR calculation it can be interpreted that about a quarter of the silonol(Si—OH) surface of the mesoporous material was modified. Under gentle conditions the optically active compound, (+)-dibenzol-tartaric anhydride, can be easily absorbed onto the surface of modified SBA-15 material. FTIR spectrum confirms that this absorption procedure results in covalently tethering to the silonol surface rather than just physical absorption. Subsequently, pore size distribution experiments reveal that the state of aminopropyl group absorbed onto the surface is in head to head position with a pore size of 4.00 nm. Whereas, when the (+)-dibenzoyl-tartaric acid was attached to the modified SBA-15 surface, it is orientated in a layered format over the SBA-15-(CH₂)₃NH₂ surface, resulting in a pore diameter of 3.50 nm.

Key words: SBA-15 molecular sieve, Chiral grafting on the surface, Nitrogen adsorption, FTIR analysis