Facile synthesis of high-density poly(octadecyl acrylate)-grafted silica for reversed-phase high-performance liquid chromatography by surface-initiated atom transfer radical polymerization

To introduce high-density polymeric organic phase onto silica, initiator-modified silica was prepared and then surface-initiated atom transfer radical polymerization (ATRP) (grafting-from method) was carried out with octadecyl acrylate. The resultant polymer-grafted silica was characterized by diffuse reflectance infrared Fourier transform, suspension-state H-1 NMR, solid-state C-13 cross-polarization magic angle spinning nuclear magnetic resonance (CP-MAS-NMR), solid-state Si-29-CP-MAS-NMR spectroscopies, elemental analysis and differential scanning calorimetry measurements. ATRP-based poly(octadecyl acrylate)-grafted silica (Sil-ODA(n)-1), was used as a stationary phase in high-performance liquid chromatography (HPLC) and the chromatographic behavior was evaluated by the retention studies of polycyclic aromatic hydrocarbons (PAHs) and aromatic positional isomers. Compared with previous poly(octadecyl acrylate)-grafted silica (Sil-ODA(n)), which was prepared by the grafting-to method, we have observed longer retention and greater selectivity for Sil-ODA(n)-1 towards PAHs event at higher temperature. (c) 2008 Elsevier B.V. All rights reserved.