The fabrication of nanometer- and micrometer-sized silica hollow spheres

摘要

Using melamine formaldehyde (MF) microspheres as hard templates and silica colloid as shell precursors, core-shell structures of silica-coated MF microspheres were prepared by the electrostatic adsorption process or spray drying inspired in-situ coating and drying process. Furthermore, nanometer- and micrometer-sized silica hollow spheres were obtained by calcinations in air. The influence of preparation methods and ratio of silica colloid to MF microspheres on the composition, the morphology and size of the core-shell intermediates and the hollow spheres were studied with FTIR, SEM and TEM techniques.