Carbon materials classification

Thus in this chapter on ACF we are dealing with the overlap or intersection of two classes of carbon materials carbon fibers and active carbons. This is illustrated in the Venn diagram. Fig. 1, which is based on a classification of carbon materials recommended by lUPAC [11]. 

Fig. 1. Venn diagram illustrating where active carbon fibers lie in the classification of carbon materials.

Because of the variety of available carbons, a classification is inevitable. Most carbonaceous materials which are capable of reversible lithium intercalation can be classified roughly as graphitic and non-graphitic (disordered). 

There are several classifications of carbon materials, given in accordance with their different properties. Hard carbon is meant as a carbon... 

Fig. 15.1 Classification of sp2- and sp3-hybridized nanostructured carbon materials. CNTs are considered as open-end tubes, thus also exposing prismatic edge surfaces.

FIGURE 2.27 Classification of nanotexture for carbon materials in graphite family. 

Structural criteria provided by techniques such as X-ray diffraction, Raman spectroscopy, and, especially, transmission electron microscopy help to establish a rational classification of the tvide range of carbon materials. The degrees of graph tization and orientation of the basic constituents justify the properties of very different types of carbon solids. 

TABLE 5.3 Classification of pore formation in carbon materials... 

Estimates of filler consumption in plastics vary considerably because of different materials classifications and because different applications are considered. According to one estimate, 12 M toimes of fillers were used in plastics worldwide in 2002. Another suggests that around two million toimes of mineral fillers are used in plastics in North America, including 1.5 M tonnes of ground calcium carbonate, but not counting titanium dioxide (which is classed as a pigment rather than a filler). The US fillers for plastics business is worth 500 M a year, and the European market is only slightly smaller. 

C, and the graphite crystallites are very small and their content is not much. Formerly accordingly to whether become graphitized easily or difficultly, carbons are divided into soft carbons and hard carbons. This classification is just based on the precursors and could not differentiate the final carbonaceous materials. 

In this book, the applications of carbon materials are classified by product functions such as chemical, structural, electrical, and optical. This classification corresponds roughly to the various segments of industry including aerospace and automotive, metals and chemicals, electronics and semiconductor, optics, and photonics. 

Adsorption isotherms are normally developed to evaluate the capacity of AC for the adsorption of a particular molecule. The shape of the isotherms is the first experimental tool (of considerable utility) to diagnose the nature of a specific adsorption phenomenon, and it is expedient to classify the most common types, phenomenologically. There are several types of isotherms (of adsorption from solution) but those mainly found in carbon materials are the five depicted in Figure 8.4. (Note that this classification of Moreno-Castilla (2004) presents isotherm shapes in a way which differs from that of Figure 4.8 (for gas-phase adsorption)). 

Based on the graphihzation degree, carbon materials are classified into graphitized and amorphous. In fact, both consist of graphite crystallites and amorphous areas but with different contents of each species. This classification is not quantitative but qualitative. It is similar to polymers where crystallite and amorphous areas are interwoven. Generally, there are strains in amorphous areas that arise from sp -hybridized carbon atoms and graphene molecules in the ordered area. 

Material classification. The product is a mixture of carbon and graphite that may be impregnated with various metals and resins to enhance the wear properties and improve the life of the materials. 

Production and Shipment. Estimated adiponitrile production capacities in the U.S. in 1992 were about 625 thousand metric tons and worldwide capacity was in excess of lO metric tons. The DOT/IMO classification for adiponitrile is class 6.1 hazard, UN No. 2205. It requires a POISON label on all containers and is in packing group III. Approved materials of constmction for shipping, storage, and associated transportation equipment are carbon steel and type 316 stainless steel. Either centrifugal or positive displacement pumps may be used. Carbon dioxide or chemical-foam fire extinguishers should be used. There are no specifications for commercial adiponitrile. The typical composition is 99.5 wt % adiponitrile. Impurities that may be present depend on the method of manufacture, and thus, vary depending on the source. 

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