Popis: |
Courtaulds AS carbon fibres have been studied by the ESCA technique after oxidation treatments in a mixture of H2SO4 and HNO3 to increase the amount of oxygen containing groups on the fibre surface. The elements C, O, N, S, Cl, Na, Ca and Si were observed within the fibre subsurface, and their mole fractions are given. It was possible to distinguish between the contributions to the ESCA spectra originating from the fibre subsurface and the contributions coming from overlayers formed on these fibres after treatments with epoxides or amines. The analysis of the ESCA spectra taken of the epoxy or the amine treated fibres revealed that there exist oxygen and carbon concentration gradients within the fibre subsurface. |