Effect of an ultraviolet/ozone treatment on the surface texture and functional groups on polyacrylonitrile carbon fibres

• Published in: Carbon (New York) Vol. 49; no. 13; pp. 4322 - 4330
• Main Authors: Osbeck, S., Bradley, R.H., Liu, C., Idriss, H., Ward, S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-11-2011; Elsevier
• Subjects: Carbon fiber reinforced plastics; Carbon fibres; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fibers; Fibres; Fullerenes and related materials; diamonds, graphite; Functional groups; Materials science; Physics; Specific materials; Texture; Ultraviolet; X-ray photoelectron spectroscopy; Scanning electron microscopy; Alkoxides; Oxygen; Shear; Electrochemical treatment; Saturation; Ozone; Raman spectroscopy; Photoelectron spectroscopy; Texture; Surface structure; Carbon fibers; Acrylonitrile polymer; Graphite; X radiation; Hydroxyl; Carbonyls; Functional group
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2011.06.005

The effect of an ultraviolet generated ozone treatment (UV/O
3), on the surface and near surface functionality and structure of polyacrylonitrile based carbon fibres has been studied using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy, and Raman spectroscopy. Results were compared to electrochemically treated fibres. The UV/O
3 treated fibres showed increased levels of oxygen functionalities. Levels of oxygen comparable to a high level electrochemical shear treatment were achieved within 5
min of treatment (O/C 0.11
±
0.03 for both treatments). XPS O1s/C1s ratios as high as 0.3 were produced, with saturation occurring at approximately 40
min exposure. The main functional groups introduced were, in addition to hydroxyl species, alkoxides (ca. 286.5
eV), carbonyl (288.0
eV), and carboxyl (289.5
eV). Examination of the full width half maximum of the graphite peak from XPS C1s showed some disorder was introduced to the first few layers of the fibre with treatment but the effect was not evident in the Raman, i.e. in the bulk of the fibre.