Layer-by-layer self-assembly of multilayer zirconia nanoparticles on silica spheres for HPLC packings

A novel zirconia-based HPLC packing material, ZrO2/SiO2, which consists of micrometer-sized silica spheres as core and nanometer-sized zirconia particles as surface coating, was prepared by a layer-by-layer self-assembly technique. The material exhibits favorable characteristics for HPLC applications, including high surface area and pore volume, good pore structure, narrow particle size, and pore size distribution. Not only the support ZrO2/SiO2 but also the stationary-phase C18 bonded ZrO2/SiO2 exhibits excellent chemical stability. In addition, good permeability was observed for both of them. High specific area surface and good permeability of ZrO2/SiO2 permit a high loading amount of chiral polymer on it and greatly improved the enantioselectivity and resolution for some chiral separations.