Carbon structure, 140 table: fibers

What is striking in Table 2 is the extremely carbonized structure of T40. The functional group analysis of the derivatized carbon fiber surfaces is given in Table 3. 

In addition to the particulate adsorbents listed in Table 16-5, some adsorbents are available in structured form for specific applications. Monoliths, papers, and paint formulations have been developed for zeolites, with these driven by the development of wheels (Fig. 16-60), adsorptive refrigeration, etc. Carbon monoliths are also available as are activated carbon fibers, created from polymeric materials, and sold in the forms of fabrics, mats, felts, and papers for use in various applications including in pleated form in filters. Zeolitic and carbon membranes are also available, with the latter developed for separation by selective surface flow [Rao and Sircar, J. Membrane Sci., 85, 253 (1993)]. 

Physisorption measurements showed that carbon nanomaterials exhibit rather meso- and macroporous structures (maximum micropore fraction, 15% see Table 2.1). The lowest specific surface area was measured with the platelet fiber catalyst exhibiting slightly more than 100 m2/g. The Co/HB material offers 120 m2/g of surface area, and the highest BET value was determined with the Co/ MW catalyst featuring nearly 290 m2/g. Carbon nanomaterials, though, are not really porous, as the space between the graphene layers is too small for nitrogen molecules to enter. The only location of adsorption is the external surface of the nanomaterials and the inner surface of the nanotubes. 

Table 1. Micropore structure development during steam activation for CFCMS monoliths manufactured from P-200 carbon fibers.

Carbon is the most versatile element in the periodic table. Due to various bond structures such as sp3, sp2, sp hybrids, and multiple pK-pK bonds, it can form one-, two-, and three-dimensionally bond-structured substances and provide a wide range of applications.1 Carbon materials such as graphite, diamond, activated carbons, carbon fibers, and C-C composites have been extensively investigated and used for many years. Since the discovery of carbon nanotubes in 1997, carbon materials have been newly focused as frontier materials in various fields.2-15... 

As indicated by the decrease of the melting point in Table 1 and the results presented in Figures 1 and 2 the penetration of the carbon dioxide into the PET seems to accelerate changes in the crystalline structure by swelling of the fiber. For PET this effect is also well known with other swelling agents [12,13],... 

Table 8.2 Some commerciaUy important precursors, their chemical structure, and the carbon fiber yield (after Riggs, 1985).

In Table 15.3 are shown the chemical structures and Tg and of some representative thermoplastic polymers for use at high temperature (3,9). These matrices have high continuous service temperatures (120-200° C) even under wet environmental conditions. Advantages of thermoplastic over thermoset matrices are their shorter fabrication cycle (generally controlled environment storage is not required) and the possibility to be reprocessed and reconsolidated after manufacture. Poly(ether ether ketone) is a strong contender with epoxy resins for use as a matrix in composite prepregs with carbon fibers to be utilized in structural aircraft components. 

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