Advantage of the scanning tunnelling microscope in documenting changes in carbon fibre surface morphology brought about by various surface treatments

The scanning tunnelling microscope (STM) was used to examine the surfaces of P-55 pitch-based carbon fibres before and after they had experienced various surface treatments (to < 1% weight loss), which included treatment in an argon plasma, as well as oxidation in air at elevated temperature, oxygen plasma at room temperature, nitric acid bath, and an electrochemical bath. The effects of these surface treatments on the filaments could be differentiated from the micrometre scale down to the nanometre scale. The STM has been shown to be a valuable tool for viewing the surface morphology of these 10 μm filaments non-destructively in air down to the atomic scale.