The living radical polymerization (iniferter) method was used to prepare the polymer-encapsulated silica as a chromatographic stationary phase. The 2-ethylhexyl methacrylate and ethylene dimethacrylate were polymerized and grafted on the silica surface by the initiation of the iniferter bound on the silica. The influence of the synthetic conditions on the polymer layers and the chromatographic separation was studied. The linear relation between the polymerization time and the amount of the polymer grafted on the silica in certain reaction period was observed. Meanwhile, polymer-encapsulated silica could be re-initialized for the successive grafting reaction, which showed the character of the living radical polymerization. The polymer-encapsulated silica has shown good separation ability and column efficiency for the alkylbenzene, alkaline compounds and hydroxybenzoate. The alkaline compounds have small peak tailings on the polymer-encapsulated silica stationary phase, which indicated that silanol groups on the silica surface were effectively covered by the polymer layer. The work provided a new method for the synthesis of polymer-encapsulated silica.

Key words: polymer-encapsulated silica, living radical polymerization, iniferter, chromatographic stationary phase