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 γ-radiation, were characterized by means of solid-state NMR spectroscopy. The surface properties of these stationary phases were investigated by 29 Si CP/MAS and 13 C CP/MAS NMR spectroscopy. γ-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.