THE SOL-GEL METHOD - A NEW WAY TO REVERSED-PHASE MATERIALS - SYNTHESIS AND CHARACTERIZATION BY SOLID-STATE NMR-SPECTROSCOPY

The sol-gel method offers a new approach for the synthesis of reversed -phase materials used in chromatography. Co-condensation of different amounts of tetraethoxysilane (Q(0)) and trifunctional alkylsilanes (T- 0) leads to novel polymer networks with new properties, for example, h igh degrees of cross-linking and high ligand densities. Two different steps in synthesis, the sol-gel transition and the precipitation of ho mogeneous sols, are discussed. These new materials were studied by C-1 3 and Si-29 solid-state NMR spectroscopy. Further characterization was performed by BET measurements and scanning electron microscopy.