Heteroatom Contribution From Disordered Materials to Graphite through Carbonization

3 HETEROATOM CONTRIBUTION FROM DISORDERED MATERIALS TO GRAPHITE THROUGH CARBONIZATION 

Until the 1960s, crystallographers were mainly physicists, so that elemental analysis was not in fashion. They did not account for the initial stages of carbonization during which heteroatoms play an essential role. As a consequence, the gap noted in Section 1.2 between the amorphous state and turbostratic order was neither 

Organic matter exposed to a heat treatment temperature (HTT) of 1000°C was assumed to be pure carbon polluted by other forms of carbon often referred to as amorphous [14,16] and sometimes as interstitial carbons [69-70]. 

It is hardly credible that a process (carbonization) involving a low HTT leads to pure carbon. In fact, this notion is well known not to be true abundant hetero-atoms are still present after carbonization, regardless of the sample studied (e.g., chlorine in polyvinyl and polyvinylidene chloride H,0,N,S in coals, chars, cokes, or nongraphitizable carbons). Even the hydrogen inherent to aromatic molecules is too often not taken into account, a notable exception being the pioneering studies by Biscoe and Warren [71] and Warren [72]. 

FIGURE 1.26 Fourier transform infrared (FTIR) data (absorption band between 700 and 920 cm ) versus heat treatment temperature giving the concentration of aromatie C-H groups for a kerogen (kerosen shale) and a eoal (lignite). (From M. VUley. Simulation thermique de I evolution des kerogenes. These d Etat Orleans 1979. With permission.) 

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