STUDY BY SCANNING TUNELING MICROSCOPE ON POLYACRYLINITRILE BASED CARBON FIBERS
聚丙烯腈基炭纤维的扫描隧道显微镜研究

Scanning tunneling microscope (STM) was used to characterise the surface topography of Polyacrylonitrile (PAN) based carbon fibers beforc and after electrochemical treatment, stretch resistance test and high temperature-treatment. A new kind of structure, the spiral structure was found not only on the sur-face but also in the inner layer. This kind spiral structure was caused by spinning process. The structure of fi-bers contained the shape of the precursor. There were some large cracks in the carbon fibers after stretching resistance test. The large cracks would result in carbon fibers breaking under certain stress condition. The dif ference in carbon fibers before and after the high temperaturc-treatment was compared- The change of the crystalline grains was also analysed.