Synthesis of Large-Pore Silica Microspheres Using Dodecylamine as a Catalyst, Template and Porogen Agent

This paper reports a strategy combing a modified Stober method and a post-hydrothermal treatment for the fabricating of silica microspheres with large pores. Dodecylamine (DDA), used as a catalyst, template and porogen agent, plays an important role in controlling both the particle morphology and the pore expansion. By adjusting the concentration of DDA (20, 40 and 80 mmol/L) and the temperature of hydrothermal treatment (80–140 °C), the pore size ranging from 3.5 to 16 nm could be obtained. The synthesized sub-2 µm silica spheres were modified with dimethyloctadecylchlorosilane (C18) and successfully applied for the separation of aromatic compounds in high-performance liquid chromatography (HPLC). The silica may be a good candidate as HPLC packing materials.