Polymer-Derived Ceramic Microspheres with Controlled Morphology via Novel Phase Separation-Assisted Pyrolysis

In this contribution, a novel and versatile strategy named phase separation assisted pyrolysis for the preparation of polymer-derived ceramic (PDC) microspheres with controlled morphology is reported. Various Si-C-N-(Ni) magnetic microspheres with a dimension from micro- to nanoscale can be conveniently prepared by using polymeric precursor with an assistance of polymer template of linear polystyrene. The morphology of PDC microspheres could be controlled through the feed ratio of precursor and template, pyrolysis temperature, and centrifugal fractionation, which were proved with dense structure, tunable crystals, and ferromagnetic property with an ultralow hysteresis loss. During phase separation and pyrolysis, the polymeric precursor or molecular precursor as well as various polymer templates can be employed. So, this strategy to synthesize ceramic microspheres with a dimension from micro- to nanoscale is indeed general and convenient for functional PDC microspheres with well-controlled morphology.