SURFACE-ANALYSES OF POLYACRYLONITRILE-BASED ACTIVATED CARBON-FIBERS BY X-RAY PHOTOELECTRON-SPECTROSCOPY

In this work, polyacrylonitrile (PAN)-based activated carbon fibers (A CFs) were developed by the common processes of stabilization, carboniz ation, and steam activation. Those fibers were successively subjected to heat treatment in a vacuum at high temperature and reactivation in steam. The changes in specific surface area and surface chemical chara cteristics were studied. The vacuum treatment reduced the surface area dramatically, while the surface nitrogen decreased after activation i n steam and the surface oxygen was lowered upon the vacuum treatment. By curve-fitting the X-ray photoelectron spectroscopy (XPS) of C1s, O1 s, and N1s, it was shown that the forms and compositions of the oxygen -containing functionalities seemed not to be affected significantly by the above-mentioned heat-treatment processes, whereas the nitrogen-co ntaining functionalities showed some changes with these treatments. (C ) 1996 John Wiley & Sons, Inc.