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

Abstract

In this contribution, a novel and versatile strategy named phase separation assisted pyrolysis for the preparation of polymerderived 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.

Enhanced electromagnetic wave absorption of Fe‐doped silicon oxycarbide nanocomposites

“…In recent years, PDC‐based absorbing materials have been receiving considerable attention due to their high temperature resistance, good oxidation resistance, and regulable structures . However, the sole PDCs are not suitable for EMI absorbing materials considering their insufficient dielectric loss .…”

“…7 In recent years, PDC-based absorbing materials have been receiving considerable attention due to their high temperature resistance, good oxidation resistance, and regulable structures. [34][35][36][37][38][39][40] However, the sole PDCs are not suitable for EMI absorbing materials considering their insufficient dielectric loss. [41][42][43][44] To overcome this issue, considerable researches have been devoted to improve the EMI absorbing capability of the PDC.…”

Synthesis of cross‐linked polymer microspheres and pyrolysis conversion to polymer‐derived ceramics

“…Zhang et al. have prepared various Si–C–N–(Ni) magnetic ceramics microspheres with dimensions from micro‐ to nanoscale with an assistance of polymer template of linear polystyrene via a novel phase separation assisted pyrolysis strategy. Kang et al .…”

“…[25][26][27][28] Much effort has been devoted to prepare spherical PDCs. Zhang et al 29 have prepared various Si-C-N-(Ni) magnetic ceramics microspheres with dimensions from micro-to nanoscale with an assistance of polymer template of linear polystyrene via a novel phase separation assisted pyrolysis strategy. Kang et al 30 have fabricated SiC/Si 3 N 4 ceramic microspheres via the combination of emulsion technology and the PDC process.…”

High temperature self-healing SiBCN ceramics derived from hyperbranched polyborosilazanes

“…Nowadays, the high-temperature-resistant ceramic materials and ceramic matrix composites are widely used in refractory mortar, aeronautics, aerospace, and nuclear power industries as shielding coating, gas turbines, and nuclear fuel cladding materials due to their cross significant mechanical properties, electromagnetic properties, and high temperature resistance [1][2][3][4][5][6]. In the harsh environment with both high temperature and oxygen, the oxidation of ceramics always received attentions as an important topic.…”