Graphitizing and non-graphitizing carbons: Difference between revisions

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The precursors for graphitizing carbons pass through a fluid stage during pyrolysis ([[carbonization]]). This fluidity facilitates the molecular mobility of the aromatic molecules, resulting in intermolecular dehydrogenative polymerization reactions to create aromatic, lamellar (disc-like) molecules. These “associate” to create a new liquid crystal phase, the so-called mesophase. A fluid phase is the dominant requirement for production of graphitizable carbons.<ref name= Mesophase >H. Marsh and M.A. Diez (1994) " Mesophase of Graphitizable Carbons" In: Shibaev V.P., Lam L. (eds) Liquid Crystalline and Mesomorphic Polymers. Springer, New York, NY {{DOI| 10.1007/978-1-4613-8333-8_7 }}</ref>

Non-graphitizing carbons generally do not pass through a fluid stage during carbonization. Since the time of Rosalind Franklin, researchers have put forward a number of models for their structure . Oberlin and colleagues emphasised the role of basic structural units (BSU), made of planar aromatic structures consisting of less than 10-20 rings, with four layers or fewer. Cross-linking between the BSUs in non-graphitizing carbons prevents graphitization.<ref>{{cite journal|author= A. Oberlin |title= Carbonization and graphitization |journal= Carbon|volume=22|pages=521–541 |year=1984|issue= 6 |doi = 10.1016/0008-6223(84)90086-1}}</ref> More recently, some have put forward models that incorporate pentagons and other non-six-membered carbon rings.<ref>{{cite journal|author= P.J.F. Harris |title= Fullerene-like models for microporous carbon |journal= Journal of Materials Science |volume=48|pages=565–577|year=2013 |issue= 2 |doi= 10.1007/s10853-012-6788-1|s2cid= 14903411 |url= http://centaur.reading.ac.uk/28956/1/Revised%20JMS%2031%20July%20For%20Centaur.pdf }}</ref>

==See also==