[Preparation of polymer modified stationary phases through surface radical chain transfer reaction]

It is demonstrated that radical chain transfer to thiol-terminated self-assembled monolayer and surface-initiated polymerization could be used for in-situ grafting ultra-thin polymer film on silica. The widely used silane coupling agent mercaptopropyltrimethoxysilane (MPS) was used to prepare the thiol-terminated silica, and in the presence of which, chain-transfer reaction and polymerization of methyl methacrylate (MMA) was carried out using azo di-isobutylnitrile (AIBN) as the initiator. Both thiol-terminated silica and polymer film modified silica were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA) and elemental analysis. The results showed that the grafting amount of polymer on silica was higher than the traditional methods, which can effectively relieve the non-specific adsorption of solute with uncovered hydroxyl groups on the surfaces of silica in subsequent chromatographic application. The obtained polymethylmethacrylate (PMMA) modified silica exhibited excellent separation capacity on the separation of the polar compounds and polycyclic aromatic hydrocarbons. This kind of surface initiated polymerization prospects for the preparation of polymer modified stationary phases.