Synthesis of three-dimensionally ordered macroporous silica spheres by evaporation-induced assembling template process

Three-dimensionally ordered macroporous silica microspheres were fabricated by colloidal crystal templating method. The colloidal crystals were assembled through the crystallization of monodisperse charged polystyrene (PS) particles during the evaporation of suspension droplets in the self-assembly process. Viscous silicone oil was used as dispersion medium to confine specific geometry. Followed by infusing silica precursor into colloidal crystals and a final calcination for PS removal, silica skeleton was formed in the interstices and macropores were left at PS′s sites. The macroporous silica made by this method was macroscopically spherical with a diameter of few tens of micrometers and the pores were close-packed and well-ordered in three-dimensions. This paper provides a facile technique to fabricate ordered colloidal crystal microballs and macroporous materials.