High frequency capacitively coupled RF plasma discharge effects on the order/disorder structure of PAN-based carbon fiber

• Published in: Journal of theoretical and applied physics 2014-06, Vol.8 (2), p.1-8, Article 127
• Main Authors: Güngör, Ümmugül E., Bilikmen, Sinan, Akbar, Demiral
• Format: Article
• Language: English
• Subjects: Applied and Technical Physics; Atomic; Carbon fibers; Condensed Matter Physics; Disorders; Hafnium; High frequencies; Joining; Medical and Radiation Physics; Molecular; Nanoscale Science and Technology; Nitrogen plasma; Optical and Plasma Physics; Order disorder; Physics; Physics and Astronomy; Plasma (physics)
• ISSN: 1735-9325; 2251-7227; 2251-7235
• DOI: 10.1007/s40094-014-0127-7

High-resolution confocal Raman microscopy was used to investigate the effects of nitrogen plasma on unsized high strength (HS) PAN-based carbon fiber surfaces. The fibers were treated by a high frequency (40.68 MHz) capacitively coupled single RF-PECVD reactor under different processing conditions (exposure times, RF powers and gas pressures). It was found that the order/disorder structure of the treated carbon fiber changed with different processing conditions. At low pressures, the degree of disordered structure increased with HF–RF power and process time. However, at high pressures, high-order structure ( I G / I T = 84.51 ) was observed and almost no observable structural effects appeared at long treatment time. Also, the first-order Raman-band peaks (D and G) of the treated carbon fibers shifted. And, FWHM ( w D / w G ), intensity ( I D / I G ) and D-band relative integrated intensity ( I D / I T ) ratios increased with ordering whereas they decreased with disordering.