In-situ Synthesis and Normal Chromatographic Properties of Nonporous SiO₂/ZrO₂ Core-shell Composite Microspheres

Abstract

Sub-2 μm core-shell SiO₂/ZrO₂ composite microspheres with nonporous SiO₂ as the cores and ZrO₂ nanoparticles as the shells were synthesized by sol-gel method in the current work. The fabrication consisted of (1) preparing monodisperse silica spheres; (2) coating the spheres with zirconia nanoparticles in-situ; and (3) calcining the composite microspheres at 823 K. Then uniform, regular, and ordered arrays of nanometer-scale zirconia crystalline particles were formed and dispersed on the surfaces of nonporous silica microspheres. A potential deposition mechanism in the synthesis process was proposed according to isoelectric point theory and to observe microstructural characteristics. The result showed that this stationary phase also has an advantage in the separation of basic compounds in the normal phase.