Synthesis and solid-state NMR investigations of radiation-immobilized polysiloxanes on bare, titanium-grafted, and zirconium-grafted silicas

Three different reversed-phase materials for high-performance liquid chromatography, obtained by sorption of poly(methyloctylsiloxane) (PMOS) onto bare silica, titanized silica, and zirconized silica pores, followed by immobilization with gamma -radiation, were characterized by means of solid-state NMR spectroscopy. The surface properties of these stationary phases were investigated by Si-29 CP/MAS and C-13 CP/MAS NMR spectroscopy, gamma -Radiation causes the formation of new bonds, either between PMOS and the different supports or between different siloxane chains, which leads, in either case, to a higher amount of polysiloxane immobilized onto the silica support material.