First-stage intercalation compound

Frontier between Polynuclear Aromatic Compounds and Graphite. The calcined petroleum coke shows chemistry that contains components of both graphite and polynuclear aromatic hydrocarbons. Like graphite, the calcined petroleum coke forms first-stage intercalation compounds with both potassium and cesium metals. These compounds are iden-... 

Herold et al. have suggested that the insertion of elements into graphite could be applied to the separation of isotopes. In a study of the equilibrium between rubidium and the first-stage intercalation compound RbCg, it has been shown that the inserted metal is more rich in the heavier isotope than the free metal. A coefficient of enrichment, K, has been estimated from the data ... 

Pure perchloric acid has been observed to react slowly with graphite at room temperature, to give the first-stage intercalation compound C24.9, CIO4,2HCIO4 and chlorine trioxide... 

Structure of the first-stage intercalation compounds EuCg and YbC 96... 

Stages. Intercalation compounds have a large spread of composition as the percentage of intercalated material changes by regular steps as shown in Fig. 10.4.1 In the first stage, intercalation reaches a maximum and the material is considered stoichiometric and is known as a first-stage compound. 

Simplified schematic of the intercalation/exfoliation process. Graphite is intercaiated with potassium to form the first-stage intercalation graphite compound, KCs, and then exfoliated in aqueous solvent to produce GNPs with 40 15 layers thick. (Adapted from reference 112). 

The reversible intercalation of various oxoacids under oxidizing conditions leads to lamellar graphite salts some of which have been known for over a century and are now particularly well characterized structurally. For example, the formation of the blue, first-stage compound with cone H2SO4 can be expressed by the idealized equation... 

Figure 8.5 Schematic representation of staging in graphite intercalation compounds (a) third stage (b) second stage and (c) first stage.

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