Carbon fibers surface properties

Lee RN, Carbon fiber surface properties, Lee SM, ed.. International Encyclopedia of Composites,... 

Dai, Z.S., Shi, F.H., Zhang, B.Y., Li, M., Zhang, Z.G., 2011. Effect of sizing on carbon fiber surface properties and fibers/epoxy interfacial adhesion. Apphed Surface Science 257, 6980-6985. 

Bell, 1989 Rhee and Bell, 1991), random copolymers of methyl acrylate and acrylonitrile were directly polymerized onto the carbon fiber surface. Dimethyl formamide, dimethyl sulfoxide and distilled water proved to be useful as solvents for this process. Polymerization can take place on the carbon fiber electrode, with initial wetting of the fiber surface leading to better adhesion of the polymer formed. The structure and properties of the polymer can be varied by employing different vinyl and cyclic monomers in homopolymerization. Chemical bond can also be formed, such as polymer grafting to the carbon fiber surface. 

In order to improve the surface properties of carbon fibers without affecting the mechanical properties of the reinforcing fibers, various monomers, including pyrrole and carbazole, were used to electrograft conjugated copolymers and produce homogeneous and continuously coated carbon fiber surfaces <2001SM391>. 

VUKOV GRAY Properties of Carbon Fiber Surfaces... 

Even though carbon fiber surfaces usually contain small amounts of hetero-atoms (for example, 0, N), they are composed primarily of graphitic basal planes and prismatic edge surfaces, and thus their surface properties should be close to those of graphites and graphltlzed carbon black. 

The nature of carbon fiber surfaces were investigated by IGC in terms of dispersive and non dispersive contributions to total surface energy. The acidic or basic properties of the thermoplastic polymers was quantified by CIGC. 

A. Shindo, Chemical Property of Carbon Fiber Surface and Interfacial Compatibility of Composites, Proc. 1st Int. Conf. Composite Interfaces, North Holland, NY, 1986, pp. 93-100. 

Fitzer E, Geigl KH, Hiittner W, The influence of carbon fiber surface treatment on the mechanical properties of carbon/carbon composites. Carbon, 18, 265, 1980. 

Manocha LM, Yasuda E, Tanabe Y, Kimura S, Effect of carbon fiber surface treatment on mechanical properties of C/C composites. Carbon, 26, 333, 1988. 

Shindo A, Chemical property of carbon fiber surface and interfacial compatibility of composites, Ishida H, Koenig JL, eds.. Composite Interfaces, North Holland, New York, 93, 1986. 

ABSTRACT. The paper focuses on carbon fibers including carbon fiber preparation, the physical properties of carbon fibers, functional groups present on carbon fiber surfaces and the relationship of surface chemistry to composite properties. Specific topics include thermal treatment of PAN-based carbon fibers, carbon fiber structure, tensile breaking strength and modulus, surface area and surface energy, XPS analysis, and chemical derivatization. 

Adhesion between fiber and matrix can be altered by surface treating the fiber [16,17], Surface treatments of carbon fibers have been developed for epoxy systems, but the optimum surface treatment for epoxy systems may be inadequate for newer resin systems. It may also be possible that by tailoring the interface between fiber and matrix, the mechanical properties of the composite can be controlled. To tailor the interface, it is necessary to understand the nature of carbon fiber surfaces and their reactions when surface treated. 

There are many techniques for probing the chemical and physical properties of a solid surface to predict the tending of organic polymers to solid surfaces. The electronic structure of solid surfaces has been studied by measuring the thermodynamic interaction of the solid surface with simple liquids of known molecular structure. Experimental techniques for measuring the thermocfynamic interaction between solid and liquid include contact angle measurement, calorimetry, and gas chromatography. Some of these techniques are discussed below. Specific techniques related to characterization of carbon fiber surfaces are also discussed. 

To improve the interfacial properties of carbon fiber (CF) reinforced composites, an innovative and simple functionalized strategy has been proposed by grafting 4,4 -oxydianiline on to the carbon fiber surface using N3P3CI6 as novel coupling agent (Scheme 24). ... 

Carbon fibers, when used without surface treatments, produce composites with low mechanical properties. This has been attributed to weak adhesion and poor bonding between the fiber and matrix. Therefore, the carbon fibers are given surface treatments, the exact nature of which is a trade secret. This surface treatment increases the surface active sites which results in the improvements of the bonding between the fibers and the resin matrix. This tends to increase the wettability of the carbon fibers and enhances the mechanical properties [4-7]. Surface treatments may be classified into oxidative and nonoxidative treatments. An oxidative treatment involves gaseous oxidation, liquid-phase oxidation carried out chemically or electrochemically and catalytic oxidation. The nonoxidative surface treatments involves deposition of more active forms of carbon or metals such as whiskerization, pyrolytic coating, the grafting of the polymers, and metal deposition on the carbon fiber surfaces [8-11]. 

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