Polysiloxane Derived Macroporous Silicon Oxycarbide Microspheroidal Particles and Their Decoration with 1D Structures

Abstract

A simple method of synthesis for the macroporous SiOC spheroidal microparticles was developed. Preceramic polysiloxane macroporous microbeads were obtained by a one-step aqueous emulsion process involving poly(hydromethylsiloxane) (PHMS) with the addition of FeCl3·6H2O. Thermal treatment of these particles gave various SiOC materials depending on the pyrolysis temperature. Hierarchically porous spheroidal mezo-macroporous ceramers were obtained at 600 °C. Heating at 850–1000 °C gave SiOC ceramic spheroidal particles with about 60% open porosity. Ceramization at 1200–1400 °C led to the particles decorated with ceramic whiskers and wires. Heating at 1600 °C gave wires and spilled ceramic particles. These 1D ceramic structures were formed by a Vapor–Liquid–Solid (VLS) mechanism.