Structure and Morphology of Carbon Nanofiber-Polycarbosilane Precursor Derived Nanocomposites

Carbon nanofibers have been mixed with a liquid silicon carbide precursor material, polycarbosilane, to produce unique structures with a high weight fraction of nanofibers. The liquid precursor and carbon nanofiber fillers were mixed and then compacted together followed by an 850 degrees C heat treatment to crosslink and pyrolyze the precursor polymer/carbon nanofiber mixture into silicon carbide/carbon nanofiber nanocomposites. Electron microscopy and energy dispersive spectroscopy performed on the nanocomposites samples suggest good interfacial bonding between the amorphous silicon carbide and nanofiber. A thin coating of silicon carbide is formed on the carbon nanofiber surface and this coating is oxidized into silicon oxide particles that decorate the nanofibers when exposed to high transient heating by a laser pulse. Nanofibers with well adhered silicon carbide on the surfaces could lead to composites with good interfacial properties.