Fabrication of monodisperse zirconia-coated core–shell and hollow spheres in mixed solvents

The monodisperse zirconia-coated polystyrene core–shell spheres were prepared in mixed solvents. The influence of the different catalyst with deionized water or ammonia and the volume fraction of acetonitrile in the mixture were investigated systematically with TEM and SEM. The shell thickness of the zirconia-coated polystyrene spheres was found to be correlated in a quasilinear fashion with the concentration of zirconium n-propoxide. The corresponding zirconia hollow particles were obtained through calcinations. XRD results showed that calcination promoted the transformation of amorphous zirconia into monoclinic phase. And the ZrO2 hollow spheres retained spherical shape up to 900 °C.