Fabrication of silica hollow spheres using a sacrificial template method assisted with spray drying process

Core-shell composites of silica-coated MF microspheres were prepared by the hard template of MF microspheres whose surface were clad with silica colloid in a spray drying induced in-situ coating process. Furthermore, silica hollow spheres were obtained by removal of MF cores at calcinations in air. The influence of the concentration of the SiO2 colloid and the ratio of MF microspheres to the core/shell composites and the hollow spheres on the composition, the morphology and size were studied with fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).