Submicron sized organo-silica spheres for capillary electrochromatography

Spherical, non-porous organo-silica materials in the submicron size range were synthesized by sol-gel processing and tested for capillary electrochromatography (CEC). The organo-silica spheres were prepared by copolymerization of alkyltriethoxy-silanes and tetraethoxysilane under ambient conditions. The synthetic approach provides silica spheres that are uniform in size (<10% R.S.D.) and contain organic moieties (e.g., C₈) ready to be used as stationary phase for CEC, eliminating the step of stationary phase attachment after particle fabrication. The final particle size is controlled by the water concentration in the initial reaction mixture. The particles were characterized using transmission electron microscopy, gas adsorption, and FT-IR. Fast CEC separations with high efficiency can be achieved using the fabricated submicron particles.