NMR INVESTIGATIONS OF NANOSTRUCTURED CERAMICS

Nanostructured mesoporous silicates displaying hexagonally arranged ch annels, templated using a liquid crystal mesophase, were investigated using H-2 and N-15 NMR spectroscopy. It is shown that N-15 MAS NMR spe ctroscopy allows to estimate the surface acidity of mesoporous materia ls by measuring the N-H bond length via the N-15 chemical shift. Furth er, H-2 and N-15 NMR spectroscopy identify significant differences bet ween the structure of the surface area of Hr silica and MCM-41. Static N-15 NMR spectroscopy was used to differentiate between pyridine loca ted in channels perpendicular to the magnetic field from, for example, pyridine located in channels orientated parallel to the field. This o bservation offers the possibility of separating the NMR signals and th us pursuiting the goal of ''liquid phase single crystal NMR spectrosco py''.