Preparation of core-shell stationary phase by in-situ polymerization of hydrophilic polymer on silica surface and its chromatographic performance

With N-isopropylacrylamide (NIPAM) as monomer, a core-shell material was succeefully prepared by in-situ polymerization on silica microspheres surface (noted as NIPAM@Sil), which feature as hydrophilic interaction chromatography (HILIC) stationary phase. A method for in situ polymerization of polymer monomers on silica surface has been developed. It was shown that the NIPAM is evenly wrapped on the surface of silica, in the results of scanning electron microscope (SEM). The synthesized NIPAM@Sil possessed polar group of acylamino arising from the polymerization of NIPAM. As demonstrated hydrophilicity, the NIPAM@Sil showing excellent HILIC performance for separation of hydrophilic compounds. This method provide a simple approach to prepare a class of polymer coated silica core-shell stationary phase.