A study of electrochemically treated PAN based carbon fibres by IGC and XPS

Inverse gas chromatography (IGC) has been used with conventional and novel probes in conjunction with X-ray photoelectron spectroscopy (XPS) to assess the surface chemistry of a range of aged polyacrylonitrile carbon fibres. Using conventional probes the thermodynamic surface properties were investigated at 100 °C. The dispersive component of the surface free energy, , was determined and ranged from 73.1 mJ m⁻² to 92.2 mJ m⁻². Unconventional probes, chosen as analogues of the functionalities present in a potential matrix material, were also eluted through the IGC columns. Surface compositions and peak fitting of C 1s spectra from XPS analysis helped identify groups on the fibre surface. Using these results, mechanisms of interactions occurring at the interface of a carbon fibre reinforced polymer composite have been proposed. Hydrogen bonding and stronger acid-base interactions are the main mechanisms of interactions. Although, the carbon fibres are aged, oxygen and nitrogen functionalities introduced from surface treatment have remained active.