Preparation of SiC Nanofibers by Using the Polymer Blend Technique
SiC nanofibers were prepared by using polymer blend and melt-spinning techniques. Polycarbosilane (PCS) as a SiC precursor polymer was dispersed finely in novolac-phenolic resin (PF) as a carbon precursor polymer with a ratio of PCS/PF=3/7. The polymer blend was melt-spun continuously. The fibers were then soaked in an acid solution in order to stabilize them (to convert into an infusible state) and finally heat-treated at 1000°C. The resulting fibers consisted of PF-derived carbon matrix including elongated nanofibers derived from PCS. Finally, the fibers were oxidized with nitric acid to remove the carbon matrix, and the released nanofibers were collected with a membrane filter. The resulting nanofibers were several 100 nm in diameter and 100 μm or more in length. They were amorphous and contained a large amount of oxygen. A part of the nanofibers was further heated to 1500°C in a graphite tube resistance furnace, resulting in crystallization into β-SiC. The behaviors were quite similar to those of a commercially available SiC fibers derived from PCS. In order to obtain optimum conditions, the processes were examined.
P. VINCENZINI and G. MARLETTA
Z. Correa et al., "Preparation of SiC Nanofibers by Using the Polymer Blend Technique", Advances in Science and Technology, Vol. 51, pp. 60-63, 2006