1992 Volume 1992 Issue 155 Pages 307-314
The stabilized polyacrylonitrile (PAN) fiber being heat-treated in an atmosphere of nitrogen, black color material was formed at 1000-1200°C and white color material was formed at 1300-1400°C on surface of a graphite vessel.
The black color material was investigated with electron microscope; this material was observed as filamentous carbon of diameter 0.1-2μm, mainly about 0.5μm, which consisted of thin skin and many nodes such as a bamboo. A distance between two nodes was about equal to diameter or a little shorter than diameter. The thin skin of black color material was composed of 10 to 20-sheet carbon layers, of which interlayer spacing was about 0.34nm. The carbon layer of these skin and nodes was arranged such as a bag-like.
The white color material was identified as a silicon-nitride (Si3N4) filament of diameter about 1μm.
