Surface analysis of unsized and sized carbon fibers

• Published in: Carbon (New York) Vol. 37; no. 7; pp. 1105 - 1114
• Main Authors: Dilsiz, Nursel, Wightman, J.P
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1999; Elsevier Science
• Subjects: A. Carbon fibers; Applied sciences; Atomic force microscopy (AFM); B. Surface treatment; Building materials. Ceramics. Glasses; C. X-ray photoelectron spectroscopy (XPS); Ceramic and carbon fibers; Ceramic industries; Chemical industry and chemicals; D. Surface properties; Exact sciences and technology; Technical ceramics; A. Carbon fibers; C. X-ray photoelectron spectroscopy (XPS); Atomic force microscopy (AFM); D. Surface properties; B. Surface treatment; Atomic force microscopy; Surface properties; Photoelectron spectrometry; X ray; Contact angle; Surface analysis; Experimental study; Surface energy; Surface treatment; Carbon fiber
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/S0008-6223(98)00300-5

Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle analyses were performed on unsized and sized carbon fibers to better understand the mechanism of adhesion in carbon fiber/polymer matrix composites. AFM images and surface roughness analyses showed that the sizing changes the surface topography on a microscopic scale. The total surface energy decreased from 70 mJ/m 2 for unsized fiber to 54 mJ/m 2 for Ultem® sized and to 36 mJ/m 2 for PTPO sized fibers. The percentage of functional groups on the sized fibers decreased slightly compared to the unsized fibers. The surface functional groups and surface energies of fibers are critical properties in predicting fiber/matrix adhesion. Angle dependent XPS, voltage contrast XPS, and perimeter measurements revealed that the thickness of the poly(thioarylene phosphine oxide) (PTPO) sizing on the carbon fiber surface was greater than for the poly(etherimide) (Ultem®) sizing.