Ry. Qin et Jp. Donnet, STUDY OF CARBON-FIBER SURFACES BY SCANNING-TUNNELING-MICROSCOPY .3. CARBON-FIBERS AFTER SURFACE TREATMENTS, Carbon, 32(2), 1994, pp. 323-328
The effect of surface treatments on carbon fibers has been studied by
scanning tunneling microscopy (STM). The results show that over a wide
range of oxidation degrees the anodic or electrochemical oxidation do
es not change the surface aspects, neither at microscopic scale nor at
nanometric scale, while the air plasma oxidation under the experiment
al conditions gives rise to surface roughness and surface degradation.
The results at atomic resolution have also revealed that the electroc
hemical treatment yields a modest oxidation on the surface of carbon f
iber and that the oxidation attack takes place preferentially at edge
sites of graphitic crystallites. The microstructure of the fibers afte
r anodic oxidation resembles very much that of low-temperature carboni
zed fibers observed by STM. The structural imperfection has been tenta
tively interpreted in terms of the formation of intercalated graphite
compounds that render the graphite layer stacking imperfect.