Electrical conductivity of graphite

The low cost, light weight, and exceUent electrical conductivity of graphite anodes have made this impressed current protection system valuable for cathodic protection of pipelines, storage vessels, process equipment, and also for weU casings both on- and offshore. 

The HF-SbFs system is known to be a superacid H34). The possible relevance of this to the intercalation process was pointed out by Vogel V12), who first reported on the extremely high electrical conductivity of graphite-SbFj measured normal to the crystallographic c-axis. The measured conductivity was approximately 40 times that of pristine graphite, and 50% greater than that of pure copper. Other workers... 

The electrical conductivity of graphite parallel to its planes is different from that perpendicular to them. Parallel to the planes, the conductivity decreases as the temperature is raised but perpendicular to them, it rises. In what sense is graphite a metallic conductor or a semiconductor ... 

The non-localization of the tt electrons, as described by the molecular orbital treatment, explains the high electrical conductivity of graphite. The various layers of graphite are held together by... 

T. E. Thompson, E. M. McCarron and N. Bartlett, The Electrical Conductivity of Graphite-AsFs Intercalation Compounds and Their Relationship to Other Graphite-MFe Salts, Synthetic Metals 3 (1981) 255-267. 

Consists structurally of large sheets of fused benzene-like hexagonal units. A n-bonding network of delocalized electrons accounts for the high electrical conductivity of graphite. 

The four valence electrons of carbon are involved in three a bonds and one tt bond with its neighbors in plane. The electrical conductivity of graphite is due to TT bonded electrons. In contrast to insulator diamond, the electrical resistance of graphite along the basal plane direction is 4.1 X cm, a figure of the same... 

One 2p orbital remains unhybridized on each carbon and is perpendicular to the plane of carbon atoms, as shown in Fig. 16.28. These orbitals combine to form a group of closely spaced tt MOs that are important in two ways. First, they contribute significantly to the stability of the graphite layers because of the ir bonding. Second, the ir MOs with their delocalized electrons account for the electrical conductivity of graphite. These closely spaced orbitals are exactly analogous to the conduction bands found in metal crystals. 

X10 S cm . However, the electric conductivity of graphite obtained from poly( 1,4-phenylene ethyny-lene) is still higher, namely, 0.80 x 10 S cm . ... 

Graphite is an allotrope of carbon in which each carbon atom is bound to three other carbon atoms and has a fourth electron which is able to move about between carbon atoms. This stmcture accounts for the excellent electrical conductivity of graphite. Another important properly of graphite is that it is a layered material composed of multilple layers of single sheets, called graphene, which are bound together by weak van der Wall attractions. 

In contrast, the bond between the planes of h-BN is very weak and even weaker than that of graphite. It is readily broken and layers can be cleaved with a knife like an onion skin. However this bond is electronically different from that in graphite. In graphite, it stems from the hybridized fourth valence electron which is paired with another delocalized electron of the adjacent plane by a weak van der Wools bond (pi bond). The high electrical conductivity of graphite is attributed to these delocalized electrons. 

Anisotropic Characterized by having physical properties that vary along different axes, for example, the electrical conductivity of graphite. 

Compare the structures of diamond and graphite. How do the structures of these substances explain the hardness of diamond and the electrical conductivity of graphite ... 

Xiao M, Du X S, Meng Y Z, Gong K C (2004), The influence of thermal treatment conditions on the structures and electrical conductivities of graphite oxide . New Garbon Materials, 19(2), 92-96. 

---