Structure of carbon fibers

Figure 8. (a) Schematic structure of carbon fibers and (b) an SEMof a Melblon 3100 fiber showing the fiber and internal structure of a fracture. 

Morpholine chromate, molecular formula, properties, and uses, 6 562t Morphology. See also Structure of carbon fibers, 26 737-739 of high density polyethylene, 20 162 of polymer blends, 20 356 of polymer colloid, 20 386-388 of PVC particles, 25 658-661, 661-663, 664-665... 

Structural steels, tellurium in, 24 425 Structure(s), see also Chain structure Chemical structures Cocontinuous structures Controlled structure Crystal structure Molecular structure Morphology Phase structure of carbon fibers, 26 737-739 detersive systems for, 8 413t HDPE, 20 157-162 LLDPE, 20 182-184, 203-205 polyesterether elastomer, 20 72-73 polyester fiber, 20 21 polyether antibiotics, 20 137-139 polyimide, 20 276-278 polymer, 20 395-405 protein, 20 449 PTT, 20 68t... 

Creation of the advanced emitting surface of the field emission cathode is provided not only by an internal structure of carbon fibers, but also by corresponding preliminary forming of the cathode. 

Using the plasmachemical method [3] of etching it was possible to receive the corresponding structure of carbon fibers bundle. 

Figure 8.8 (a) Two-dimensional representation of the lamellar structure of carbon fiber (b) lamellar structure of carbon fiber as seen in TEM (courtesy of D.J. Johnson). 

Theoretical predictions of carbon nanotubes are largely unknown in the literature. Still there is a rich collection of publications on the structure of carbon fibers that include in their discussion the tubular core of the fibers. However, these facts were largely ignored until after the discovery of carbon nanotubes because it seemed unhkely ever to be able to obtain the isolated core of such a fiber. 

Catalysts were prepared by impregnation of Pt inside the pore structure of carbon fibers. Care was taken to eliminate the active metal from the external surface of the support. A very high dispersion of Pt was measured. Four reactions were carried out in a fixed-bed reactor competitive hydrogenation of cyclohexene and 1-hexene, cyclization of 1-hexene, n-heptane conversion and dehydrogenation of cyclohexanol. Three types of carbon fibers with a different pore size and Pt-adsorption capacity along with a Pt on activated carbon commercial catalyst were tested. The data indicate a significant effect of the pore size dimension on the selectivity in each system. The ability to tailor the pore structure to achieve results drastically different from those obtained with established supports is demonstrated with heptane conversion. Pt on open pore carbon fibers show higher activity with the same selectivity as compared with Pt on activated carbon catalysts. 

Nakamura, A. and Iji, M. (2009) Enhancement of thermal diffusivity of poly(L-lactic acid) composites with a net-like structure of carbon fibers. Journal of Materials Science, 44, 4572—4576. 

Figure 5.18 Schematic of an idealized diagram for the structure of carbon fiber summarized from X-ray diffraction evidence. Si, void Sa, subgrain twist boundary S3, intercrystalline boundary. and are thickness and diameters of carbon layer stacks and D the distance between them. Source Reprinted from Johnson DJ, Tyson CN, The fine structure of graphitized fibres, Brit J Appi Phys (J Phys D), 2(2), 787-795, 1969.

Figure 5.19 Interlinked structure and resulting void in an idealized structure of carbon fiber. Source Reprinted from Johnson DJ, Structure property relationships in carbon fibres, J Phys D AppI Phys, 20(3), 285-291, 1987.

Figure 12.7 Structure of carbon fiber, (a) A schematic iiiustralion of tree trunk or onion skin structure (ieft) and radial structure (right), (b) A typicai opticai micrograph of carbon fiber cross sections under polarized light in crossed nicols condition showing maltose cross patterns. Polarizer and analyzers are parallel to picture edges. Source Reprinted from Nyo H, Heckler AJ, Hoemschemeyer DL, Characterizing the structures of PAN based carbon fibers, 24 Nat Symposium, San Francisco, 179, 51-60, May 8-10.

---