Pore expansion of highly monodisperse phenylene-bridged organosilica spheres for chromatographic application

Monodisperse phenylene-bridged organosilica spheres show great potential as chromatographic stationary phase. In this paper, the tunable particle size of monodisperse phenylene-bridged organosilica spheres were prepared by co-condensing different proportion of 1,4-bis(triethoxysilyl)benzene (1,4-BTEB) and tetraethylorthosilicate (TEOS), and then pore size was expanded by two-step post-synthesis hydrothermal treatments using N,N-dimethyldecylamine (DMDA)/dodecylamine (DDA) and tris-(hydroxymethyl)-aminomethane (TRIS) in turn. Phenylene-bridged organosilica spheres with particle size of 3.0–3.5 μm and pore size of 85 Å were further surface modified by C18 group and tested in reversed-phase high performance liquid chromatography (RP-HPLC). The primary chromatographic results demonstrated that C18 bonded phenylene-bridged organosilica stationary phase has high retention and good chemical stability in the high pH mobile phase, which indicated that the phenylene-bridged organosilica can be used for HPLC packing supports.